Very rough idle... Popping and spluttering!
09-30-17, 11:17 AM
#26
Full Member
Thread Starter
I know when you search this topic on this forum you have reputable members explaining that the power increase is a placebo and it only leads to idle issues. Unfortunately I have no first hand experience to share.
Are you checking the TPS with the diode method? Mazda's diode method is supreme imo. I set my TPS to 1v and it was very close to perfect but it wasn't perfect because both lights were on when I tested via diode method. I forget what my voltage is on my TPS is but do remember that it isn't sitting at 1.00v.
If nothing else has changed accept the removal of the plates then I would suspect, logically, that the problem has cropped up because of the mod. If all else fails I would reinstall the plates and see if it fixes the issue.
Keep us updated!
Are you checking the TPS with the diode method? Mazda's diode method is supreme imo. I set my TPS to 1v and it was very close to perfect but it wasn't perfect because both lights were on when I tested via diode method. I forget what my voltage is on my TPS is but do remember that it isn't sitting at 1.00v.
If nothing else has changed accept the removal of the plates then I would suspect, logically, that the problem has cropped up because of the mod. If all else fails I would reinstall the plates and see if it fixes the issue.
Keep us updated!
My plan is to reinstall everything which at least puts me back to a blank slate. I'll report back when done.
09-30-17, 01:28 PM
#27
Sucker for Punishment
Aaron Cake has a detailed write up on the 1V technique at idle(paperclip method?). This method works very well at getting you very close to perfect. At least for my car. However people seem to satisfied with the results of both techniques. Hands down though, using the diode method(checker lamp method in the FSM) lets you visually observe, without a doubt, that you are set correctly. As I mentioned, your car might not want to see 1k or 1V, it may be expecting 1.1k or .9V. That's why there is a range of settings... every car is unique to itself when it comes to the perfect idle mixture. The confusion starts when someone says it has to be set to exactly this or that.
When they were compiling research for the FSM I'm sure they set so many cars and then observed that on average the readings were 0.8k to 1.2 k resistance or whatever the spec is. I imagine even, that 1-3% of our cars are out of this range and run perfectly fine because the settings are right for that car. These things are not explained in the FSM and I can see how it leads people(even me until I had the revelation) to believe that the settings can be between this and that.
I'd say that in all the years of working on this freakin' frankenstein that the TPS has proven itself to be the most complicated part on the car. The FSM has merely one page of info but when you expand that info into practical terms it can literally turn into pages and pages of information haha.
When they were compiling research for the FSM I'm sure they set so many cars and then observed that on average the readings were 0.8k to 1.2 k resistance or whatever the spec is. I imagine even, that 1-3% of our cars are out of this range and run perfectly fine because the settings are right for that car. These things are not explained in the FSM and I can see how it leads people(even me until I had the revelation) to believe that the settings can be between this and that.
I'd say that in all the years of working on this freakin' frankenstein that the TPS has proven itself to be the most complicated part on the car. The FSM has merely one page of info but when you expand that info into practical terms it can literally turn into pages and pages of information haha.
Last edited by Rotary Alkymist; 09-30-17 at 01:37 PM.
10-06-17, 02:41 PM
#28
Full Member
Thread Starter
Okay, update.
Had a day working on the car today, tried a lot of stuff, but its still got exactly the same problem. Rough idle, engines shaking and its not idling high enough no matter that I set it to. (Around 600rpm ish is the most it will go when warmed up.)
Drives perfectly, apart from it has some flat spots it never used to have.
So today I reinstalled the secondary butterflies that I removed before, adjusted the fast idle (works perfectly now), while the UIM was off I triple checked all connections, vacuum lines etc, all good.
Reinstalled it all, same issue, no matter how I set the idle speed, or the mixture resistor.
To see if it was the cause of my problems I next removed the ACV, and fabbed up some ally plates to fit on the exhaust and intake manifold where I had removed ACV parts. I then removed the AAV and Air Relief solenoids and capped off all vacuum lines associated with those systems.
It runs just the same, but now I get a pop from the exhaust when changing gear, even at steady speeds around town! So I may end up refitting it all.
I'm trying to work out what to do next, I'm sure there are no vacuum leaks, and everything is hooked up correctly.
I'm going to try and arrange for a proper compression test as soon as I can find somewhere not a 100 miles away, although as it drives fine and its just the idle then I don't think it will help too much .
I got a video, the quality got killed on the upload, and its hard to tell. The idle speed you hear is the absolute highest it will go without throttle input.
RX7 Idle
Had a day working on the car today, tried a lot of stuff, but its still got exactly the same problem. Rough idle, engines shaking and its not idling high enough no matter that I set it to. (Around 600rpm ish is the most it will go when warmed up.)
Drives perfectly, apart from it has some flat spots it never used to have.
So today I reinstalled the secondary butterflies that I removed before, adjusted the fast idle (works perfectly now), while the UIM was off I triple checked all connections, vacuum lines etc, all good.
Reinstalled it all, same issue, no matter how I set the idle speed, or the mixture resistor.
To see if it was the cause of my problems I next removed the ACV, and fabbed up some ally plates to fit on the exhaust and intake manifold where I had removed ACV parts. I then removed the AAV and Air Relief solenoids and capped off all vacuum lines associated with those systems.
It runs just the same, but now I get a pop from the exhaust when changing gear, even at steady speeds around town! So I may end up refitting it all.
I'm trying to work out what to do next, I'm sure there are no vacuum leaks, and everything is hooked up correctly.
I'm going to try and arrange for a proper compression test as soon as I can find somewhere not a 100 miles away, although as it drives fine and its just the idle then I don't think it will help too much .
I got a video, the quality got killed on the upload, and its hard to tell. The idle speed you hear is the absolute highest it will go without throttle input.
RX7 Idle
Last edited by theDevilX; 10-06-17 at 02:53 PM.
10-07-17, 09:27 AM
#29
rotorhole
that's not nearly as bad as you made it sound, i've seen people running on one rotor who made it sound like their car barely had a problem, lol.
spray around the intake with some carb cleaner to double check for vacuum leaks is where i'd start.
unfortunately i don't know how the eurospec cars drop down into idle timing mode with the distributor like the USDM cars do with the digital timing. what you can do is tell us what timing you are seeing with the car at idle though, ours idles with the leading at 5ATDC and trailing at 20ATDC, it makes a huge difference once the timing goes into the positive numbers for advance as to how smooth the engine idles. your car does sound identical to how a USDM car would idle above 1000 RPMs and out of the base idle timing mode once the timing begins to advance, so i suspect your timing is somehow the culprit.
spray around the intake with some carb cleaner to double check for vacuum leaks is where i'd start.
unfortunately i don't know how the eurospec cars drop down into idle timing mode with the distributor like the USDM cars do with the digital timing. what you can do is tell us what timing you are seeing with the car at idle though, ours idles with the leading at 5ATDC and trailing at 20ATDC, it makes a huge difference once the timing goes into the positive numbers for advance as to how smooth the engine idles. your car does sound identical to how a USDM car would idle above 1000 RPMs and out of the base idle timing mode once the timing begins to advance, so i suspect your timing is somehow the culprit.
10-07-17, 10:58 AM
#30
Full Member
Thread Starter
That's the next thing I'll check then, we have a green initial set coupler for setting the timing like you guys, so I assume you mean I should leave it off and just see what the timing is like 'as is'?
For timing, according to the Training manual, for the distributor vacuum is cut by the VCV solenoid when the engine speed is less than 1200 rpm, leaving just the centrifugal advance. Once the engine speed is above that then vaccum is applied to advance the timing.
It also looks like the painted marks are long gone from the pulley, so I'll take off the fan (for better access) and hopefully there'll be something scribed in place.
For timing, according to the Training manual, for the distributor vacuum is cut by the VCV solenoid when the engine speed is less than 1200 rpm, leaving just the centrifugal advance. Once the engine speed is above that then vaccum is applied to advance the timing.
It also looks like the painted marks are long gone from the pulley, so I'll take off the fan (for better access) and hopefully there'll be something scribed in place.
10-08-17, 11:04 AM
#33
Full Member
Thread Starter
The gasket between the the upper and lower intake manifolds is still in place, I've not even attempted to disturb it as it looks in good condition.
10-08-17, 11:41 AM
#34
Sucker for Punishment
Before fooling around with anything else check your plugs. You'd be surprised what kind of problems crop up from fouled/damaged/worn out plugs. I ended up inspecting my whole fuel system because the problem seemed to be fuel related in every way. Popping, backfiring, major hesitations when secondaries opened up.
I'll also mention that the car was parked for about two weeks and ran absolutely perfect before she sat for that time. Then boom, crappy idle, backfiring, etc. I noticed well into my fuel system inspection that my exhaust smelled like ****. I could've saved myself hours of work if I would've inspected my plugs. ALWAYS check plugs when an idle problem emerges. It's rotary 101... I just had to learn the hard way.
Question: Does your exhaust smell like your cat is working too hard? If you find that your exhaust stinks at idle like you're barreling down the highway then I would instantly suspect bad plugs. It will start fine and it will fool you into thinking it's fuel related... and it is ... because the fuel is going into your exhaust because your plugs simply aren't doing their job. It takes 20 minutes to inspect your plugs. Post pics.
If your plugs are good then NCross made a good point stating that you are the only one who can solve this.
Every setting has been tampered with.
Mixture settings should NEVER be touched unless variable resistor is being replaced.
Also variable resistor, once adjusted, should NEVER be touched.
As unfortunate as it is you have tampered with these VERY touchy settings.
The best advice I can give you is acquire a FSM not a haynes or anything else. The real deal.
Take a long hard look at Fuel and Emissions for N/A and follow the instructions to the letter. Buy or make the necessary feeler gauges.
These throttle bodies last forever man. If these settings are done in the wrong order you will fail. All settings are utterly dependent on the mechanical settings. No sensor works right when the mechanical setting is off.
Good luck man. I hope you find your issue.
EDIT: I know this is already too long but be prepared to buy tools man. Compression tester, fuel pressure gauge, vacuum gauge, feeler gauges....gauges gauges gauges...multimeter... build a checker lamp to pull codes and save time. If you own an rx7 you will need an arsenal of tools to keep your car running good and to keep your hair connected to your scalp lol. And most importantly, to keep your hard earned money in your pocket... to spend on gasoline!
I'll also mention that the car was parked for about two weeks and ran absolutely perfect before she sat for that time. Then boom, crappy idle, backfiring, etc. I noticed well into my fuel system inspection that my exhaust smelled like ****. I could've saved myself hours of work if I would've inspected my plugs. ALWAYS check plugs when an idle problem emerges. It's rotary 101... I just had to learn the hard way.
Question: Does your exhaust smell like your cat is working too hard? If you find that your exhaust stinks at idle like you're barreling down the highway then I would instantly suspect bad plugs. It will start fine and it will fool you into thinking it's fuel related... and it is ... because the fuel is going into your exhaust because your plugs simply aren't doing their job. It takes 20 minutes to inspect your plugs. Post pics.
If your plugs are good then NCross made a good point stating that you are the only one who can solve this.
Every setting has been tampered with.
Mixture settings should NEVER be touched unless variable resistor is being replaced.
Also variable resistor, once adjusted, should NEVER be touched.
As unfortunate as it is you have tampered with these VERY touchy settings.
The best advice I can give you is acquire a FSM not a haynes or anything else. The real deal.
Take a long hard look at Fuel and Emissions for N/A and follow the instructions to the letter. Buy or make the necessary feeler gauges.
These throttle bodies last forever man. If these settings are done in the wrong order you will fail. All settings are utterly dependent on the mechanical settings. No sensor works right when the mechanical setting is off.
Good luck man. I hope you find your issue.
EDIT: I know this is already too long but be prepared to buy tools man. Compression tester, fuel pressure gauge, vacuum gauge, feeler gauges....gauges gauges gauges...multimeter... build a checker lamp to pull codes and save time. If you own an rx7 you will need an arsenal of tools to keep your car running good and to keep your hair connected to your scalp lol. And most importantly, to keep your hard earned money in your pocket... to spend on gasoline!
Last edited by Rotary Alkymist; 10-08-17 at 12:06 PM.
10-08-17, 12:05 PM
#35
Full Member
Thread Starter
I'll check the plugs, although they were new just 2 months. (or about 600 miles) ago.
Regarding the cat, I don't have one, all Euro NA cars came with the thermal reactor from the earlier generation, so the exhaust always smells like there's no cat!
I wouldn't say every setting has been tampered with.
- The cold fast idle cam was stuck in the open (engine warm position) meaning the engine died when cold at idle.
- I removed this and cleaned it up, its now operating perfectly, and once the coolant is warm the cam disengages
- I removed the secondary plates that prevent full throttle when cold, I then refitted them, but either way has made no difference. They're also opening correctly as the engine warms up.
- The TPS is set up exactly per service manual
The only other setting I have changed is the idle speed and idle mixture, but remember I changed these because of the idle issue, they didn't cause it (I also followed the adjusting procedure to the letter).
Settings like the hard throttle stop can't be adjusted as they're actually bonded into position and not actually adjustable.
I do have a the FSM and haynes manual, unfortunately they only cover USDM cars, I've spent months looking for a UK service manual and they just aren't too be found. The training manual contains most of the information I need for the EU car, but its not comprehensive.
Hopefully I get to the bottom of it eventually.
Regarding the cat, I don't have one, all Euro NA cars came with the thermal reactor from the earlier generation, so the exhaust always smells like there's no cat!
I wouldn't say every setting has been tampered with.
- The cold fast idle cam was stuck in the open (engine warm position) meaning the engine died when cold at idle.
- I removed this and cleaned it up, its now operating perfectly, and once the coolant is warm the cam disengages
- I removed the secondary plates that prevent full throttle when cold, I then refitted them, but either way has made no difference. They're also opening correctly as the engine warms up.
- The TPS is set up exactly per service manual
The only other setting I have changed is the idle speed and idle mixture, but remember I changed these because of the idle issue, they didn't cause it (I also followed the adjusting procedure to the letter).
Settings like the hard throttle stop can't be adjusted as they're actually bonded into position and not actually adjustable.
I do have a the FSM and haynes manual, unfortunately they only cover USDM cars, I've spent months looking for a UK service manual and they just aren't too be found. The training manual contains most of the information I need for the EU car, but its not comprehensive.
Hopefully I get to the bottom of it eventually.
10-08-17, 02:59 PM
#36
Sucker for Punishment
Do you use mixed fuel? I am really curious to see what your plugs look like.
I read this thread again to search for clues that might point in the right direction and I think I found one. I'd say if you're idling at 600rpm we can definitely rule out vacuum so that can be crossed off with confidence.
Your plugs have to be crossed off of the list too. Please upload pics of your plugs.
If your plugs are good then I would say, since you are able to idle at 600rpm... then I would suspect that your primary valve has to be adjusted or that your TPS voltage is too LOW.
EDIT: Do you have 89-91 manuals? There is very valuable info in there that isn't in 86-88. VERY VALUABLE!
I read this thread again to search for clues that might point in the right direction and I think I found one. I'd say if you're idling at 600rpm we can definitely rule out vacuum so that can be crossed off with confidence.
Your plugs have to be crossed off of the list too. Please upload pics of your plugs.
If your plugs are good then I would say, since you are able to idle at 600rpm... then I would suspect that your primary valve has to be adjusted or that your TPS voltage is too LOW.
EDIT: Do you have 89-91 manuals? There is very valuable info in there that isn't in 86-88. VERY VALUABLE!
Last edited by Rotary Alkymist; 10-08-17 at 03:05 PM.
10-08-17, 03:12 PM
#37
Full Member
Thread Starter
I'll download the manual. I hadn't bothered before as my car is an S4.
Fuel is standard basic 95 unleaded.
TPS was set using the resistance method. I'm not sure what you mean by the primary valve, the idle screw on top of the throttle body? Right now the most I can get is around 600rpm unless I apply throttle. The idle screw will reduce the idle (of course much lower than it is and it dies), but even at full adjustment won't increase it any more.
I'll get the plug photos, it will have to wait until wednesday though as I work 6-6 until then so there's no daylight for me to work on the car.
Fuel is standard basic 95 unleaded.
TPS was set using the resistance method. I'm not sure what you mean by the primary valve, the idle screw on top of the throttle body? Right now the most I can get is around 600rpm unless I apply throttle. The idle screw will reduce the idle (of course much lower than it is and it dies), but even at full adjustment won't increase it any more.
I'll get the plug photos, it will have to wait until wednesday though as I work 6-6 until then so there's no daylight for me to work on the car.
10-08-17, 10:04 PM
#38
Sucker for Punishment
There has to be a screw that stops the valve some slapping against the bore wall. It would be probably close to throttle cable linkage. However, if you haven't touched it then it's probably set correctly so don't touch it.
You mentioned that you set your TPS. When did you do this? Do you remember which way you had to turn it? Why was it adjusted? Was the previous setting within range? Sorry to ask. It's just that this stuff should never be touched. The manual warns the mechanic at every turn of the risks involved when changing certain settings on the throttle body. It's all written in bold letters for a reason. Worst case scenario being the throttle body has to be fully re-set.
I'll say it again ... chances are that your car is not wanting 1K on the dot. This is an approximation. Don't let this confuse you into thinking that your setting can be an approximation. You have an EXACT TPS setting for YOUR car and I'll bet money that it isn't 1.00 k ohm. Do you see how the manual can be misleading? This is why I always tell guys to do the diode test. It's the only way to know that you have it set properly. There is no other way to truly know with certainty. I will argue with someone all day about this. You cannot convince me otherwise. I say this because that test is the ECU telling YOU that the setting is acceptable. That's what those jumpers are there for. There are so many cool things you can do with this car if you know and understand the function of all green connectors. Most guys hate wires and don't take the time to learn electronics side of things.
I think focusing on one thing at a time is key to solving this issue. 'Looking forward to some plug photos.
You mentioned that you set your TPS. When did you do this? Do you remember which way you had to turn it? Why was it adjusted? Was the previous setting within range? Sorry to ask. It's just that this stuff should never be touched. The manual warns the mechanic at every turn of the risks involved when changing certain settings on the throttle body. It's all written in bold letters for a reason. Worst case scenario being the throttle body has to be fully re-set.
I'll say it again ... chances are that your car is not wanting 1K on the dot. This is an approximation. Don't let this confuse you into thinking that your setting can be an approximation. You have an EXACT TPS setting for YOUR car and I'll bet money that it isn't 1.00 k ohm. Do you see how the manual can be misleading? This is why I always tell guys to do the diode test. It's the only way to know that you have it set properly. There is no other way to truly know with certainty. I will argue with someone all day about this. You cannot convince me otherwise. I say this because that test is the ECU telling YOU that the setting is acceptable. That's what those jumpers are there for. There are so many cool things you can do with this car if you know and understand the function of all green connectors. Most guys hate wires and don't take the time to learn electronics side of things.
I think focusing on one thing at a time is key to solving this issue. 'Looking forward to some plug photos.
Last edited by Rotary Alkymist; 10-08-17 at 10:08 PM.
10-08-17, 11:09 PM
#39
Full Member
Thread Starter
I think you're referring to what we'd call the throttle stop screw or something like that. Its impossible to adjust on my car as it appears to have been bonded in position, and it looks like its been that way since the factory, either way I've not adjusted it.
The TPS was adjusted because when driving at low speeds the car had a tendency to buck a bit which made driving in traffic hard. It was out by a fair way.
This was around a month before my idle problem, and after I adjusted it the car was far nicer to drive, and the idle was still good. So it seems unlikely that this is the cause of my issues as it drove on this setting for around a month with no probs.
Either way, Wednesday I'll get plug picks and check the timing.
The TPS was adjusted because when driving at low speeds the car had a tendency to buck a bit which made driving in traffic hard. It was out by a fair way.
This was around a month before my idle problem, and after I adjusted it the car was far nicer to drive, and the idle was still good. So it seems unlikely that this is the cause of my issues as it drove on this setting for around a month with no probs.
Either way, Wednesday I'll get plug picks and check the timing.
10-09-17, 09:59 AM
#40
Sucker for Punishment
There is a write up that I think you'll find useful.
FC3S Pro v2.0:  How-To - Zenki FC3S Error Codes
This will explain how to make the checker lamp for zenki engines. The great thing is that this checker lamp can be used to for TPS setting verification.
The green connector on the passenger side... three prong? Get your car up to temp then park it, turn it off, immediately plug the checker lamp into the connector and then turn on ACC.
1. If neither diode lights you're off.
2. If both diodes light your off.
3. If one diode lights you're properly set.
This is also all explained in the manual except they expect you to buy the fancy Mazda checker lamp.
It's worth anyone's time to make this little guy... one of the most important tools you can have. Throw that in the glove compartment and you will thank yourself over and over and over...
FC3S Pro v2.0:  How-To - Zenki FC3S Error Codes
This will explain how to make the checker lamp for zenki engines. The great thing is that this checker lamp can be used to for TPS setting verification.
The green connector on the passenger side... three prong? Get your car up to temp then park it, turn it off, immediately plug the checker lamp into the connector and then turn on ACC.
1. If neither diode lights you're off.
2. If both diodes light your off.
3. If one diode lights you're properly set.
This is also all explained in the manual except they expect you to buy the fancy Mazda checker lamp.
It's worth anyone's time to make this little guy... one of the most important tools you can have. Throw that in the glove compartment and you will thank yourself over and over and over...
Last edited by Rotary Alkymist; 10-09-17 at 10:27 AM.
10-11-17, 01:32 PM
#41
Full Member
Thread Starter
Okay, so I got a small amount of time on the car today.
I pulled both leading plugs:
The first is the front, the second is the rear.
Trailing spark plugs were much the same, perhaps a little worse.
I noticed that I'd actually got the spark plugs mixed up, as in I put the leading into the trailing and vice versa. (Not that it should matter hugely)
Anyways so I decided to swap them the correct way around (after a little bit of cleaning with a brass wire brush), after this the car won't start.
I've run the deflood procedure several times, including with plugs out and injecting oil into the chamber, it catches a tiny bit but shows no real sign of starting. (the oil did come out the back as smoke though) There's definitely fuel so I think its ignition.
Anyway I've got some new spark plugs on order so that's my next port of call.
I pulled both leading plugs:
The first is the front, the second is the rear.
Trailing spark plugs were much the same, perhaps a little worse.
I noticed that I'd actually got the spark plugs mixed up, as in I put the leading into the trailing and vice versa. (Not that it should matter hugely)
Anyways so I decided to swap them the correct way around (after a little bit of cleaning with a brass wire brush), after this the car won't start.
I've run the deflood procedure several times, including with plugs out and injecting oil into the chamber, it catches a tiny bit but shows no real sign of starting. (the oil did come out the back as smoke though) There's definitely fuel so I think its ignition.
Anyway I've got some new spark plugs on order so that's my next port of call.
10-11-17, 02:38 PM
#43
Full Member
Thread Starter
Weather dependant tomorrow I'll take out the plugs and check them for spark when I turn over the engine using a jump lead to earth them.
10-11-17, 09:01 PM
#45
Sucker for Punishment
If you do get spark on even one plug use that plug to test your distributor.
Check them one by one to verify you have spark on all wires.
**Make sure all plugs are grounded when coils are functioning.
If you have smoke there is some spark going on. Your new spark plugs will take some questions off the table.
Check them one by one to verify you have spark on all wires.
**Make sure all plugs are grounded when coils are functioning.
If you have smoke there is some spark going on. Your new spark plugs will take some questions off the table.
Last edited by Rotary Alkymist; 10-11-17 at 09:06 PM.
10-11-17, 11:03 PM
#46
Full Member
Thread Starter
Never had a problem in the past using a soft brass brush. Its softer than the plug material and shouldn't cause damage.
I'll give that a go, thanks.
If you do get spark on even one plug use that plug to test your distributor.
Check them one by one to verify you have spark on all wires.
**Make sure all plugs are grounded when coils are functioning.
Check them one by one to verify you have spark on all wires.
**Make sure all plugs are grounded when coils are functioning.
10-12-17, 08:39 AM
#47
Full Member
Thread Starter
Okay, so I've tested today.
All 4 spark plugs are working, and I tested them all using their own distributor wire, so spark is getting to both leading and trailing.
I've since then done a full deflood procedure twice with the plugs out.
Still won't start.
After the deflood procedure it kicks a couple of times when turning over but that's it.
I'm now starting to wonder if something more significant has gone in the engine, I've pulled the schrader valve out of my compression tester and when I can get someone around to help I'll test the compression. Not sure how accurate it will be as all this attempted starting has probably washed a lot of oil off the cylinder walls.
All 4 spark plugs are working, and I tested them all using their own distributor wire, so spark is getting to both leading and trailing.
I've since then done a full deflood procedure twice with the plugs out.
Still won't start.
After the deflood procedure it kicks a couple of times when turning over but that's it.
I'm now starting to wonder if something more significant has gone in the engine, I've pulled the schrader valve out of my compression tester and when I can get someone around to help I'll test the compression. Not sure how accurate it will be as all this attempted starting has probably washed a lot of oil off the cylinder walls.