official whats wrong with my car thread
06-21-12, 11:46 PM
#1
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official whats wrong with my car thread
Tired of starting up a new thread for each question or issue I have with my 7. I figured I can just bring it all here. And I will get some pics here for everyone to laugh at. Seriously my white car has some black panels. Paint peeling off so gray is showing through and my new right side mirror is red. Oh and the underneath of my hood is blue.
The car was my moms '90 N/A auto and the seals went out in it and seized. I got the car from her and ordered a Jspec front clip for a '90 TII 5 speed. Since I had the whole front clip I went ahead and made a few new holes in my firewall and made it right hand drive. The worst part about the whole swap was the fact that the wire harnesses going to the rear was cut right where they cut the car in half. A lot of the wires were different colors so it took some time to follow wires and do some research to get what I needed in the rear to work. After I got it going it sat for years and I would start and run it occassionally.
Now that I'm back at it I want to get it going good. Here is what I have done to the car.
I started with upgraded exhaust. Shop was suppose to do 3'' in just found out it is only 2.5''. That goes back to monza pacesetter dual exhast.
720cc primary and secondary injectors
koyo radiator
rtec1.8
FMIC 3'' piping
aftermarket BOV
Hallman manual boost controller
aftermarket boost gauge
ported wastegate
255lph fuel pump is on its way
rats nest, air pump,thermowax removed only thing I kept was BAC
after fixing a couple issues I took it down the road a little and opened it up a little, and it seems to be running well plenty of power. It is boosting to about 8 psi with the boost controller turned all the way down. I havent messed with that yet. The hiccup I was having at 5000rpms is gone. Found a plug wire that broke.
Just checked compression and I have 3 even bumps at 80 psi on both rotors. 80psi seems low to me, the last time I checked it I remember it being higher. but that was years ago and it has been sitting.
The spark plugs look black and a little wet. So it appears to be running rich.
I hooked up a volt meter to my O2 sensor but the numbers seem off from what I have read. The volt meter was reading around .05v and when I would rev the engine the number would go down to 0.00 and down to -.05. When I checked it earlier I thought I was getting .6volts at idle but each time I checked it since then I havent got that. The Idle is jumpy like there is a miss so I'm going to clean the spark plugs and see if that helps.
That should be enough for now, mainly I want to find out what the voltage reading I got from my O2 mean and also reasons why my idle is jumpy.
The car was my moms '90 N/A auto and the seals went out in it and seized. I got the car from her and ordered a Jspec front clip for a '90 TII 5 speed. Since I had the whole front clip I went ahead and made a few new holes in my firewall and made it right hand drive. The worst part about the whole swap was the fact that the wire harnesses going to the rear was cut right where they cut the car in half. A lot of the wires were different colors so it took some time to follow wires and do some research to get what I needed in the rear to work. After I got it going it sat for years and I would start and run it occassionally.
Now that I'm back at it I want to get it going good. Here is what I have done to the car.
I started with upgraded exhaust. Shop was suppose to do 3'' in just found out it is only 2.5''. That goes back to monza pacesetter dual exhast.
720cc primary and secondary injectors
koyo radiator
rtec1.8
FMIC 3'' piping
aftermarket BOV
Hallman manual boost controller
aftermarket boost gauge
ported wastegate
255lph fuel pump is on its way
rats nest, air pump,thermowax removed only thing I kept was BAC
after fixing a couple issues I took it down the road a little and opened it up a little, and it seems to be running well plenty of power. It is boosting to about 8 psi with the boost controller turned all the way down. I havent messed with that yet. The hiccup I was having at 5000rpms is gone. Found a plug wire that broke.
Just checked compression and I have 3 even bumps at 80 psi on both rotors. 80psi seems low to me, the last time I checked it I remember it being higher. but that was years ago and it has been sitting.
The spark plugs look black and a little wet. So it appears to be running rich.
I hooked up a volt meter to my O2 sensor but the numbers seem off from what I have read. The volt meter was reading around .05v and when I would rev the engine the number would go down to 0.00 and down to -.05. When I checked it earlier I thought I was getting .6volts at idle but each time I checked it since then I havent got that. The Idle is jumpy like there is a miss so I'm going to clean the spark plugs and see if that helps.
That should be enough for now, mainly I want to find out what the voltage reading I got from my O2 mean and also reasons why my idle is jumpy.
06-22-12, 03:26 PM
#3
So what you have essentially said is that the idle is a little crappy, but the spark plugs are fouled and that you're going to remedy that situation. I can't find anything else wrong except that the o2 sensor is reading low, but we really don't know what it's reading because I don't have a chart that says what the O2 sensor should read. If there really is a problem with the car, spit it out! A jumpy idle is with a properly running car is actually something to be happy about, since that's a whole lot more than a lot of people can say about their cars.
Clean or replace those spark plugs, adjust the throttle position sensor, use some carburetor/throttle body spray to look for vacuum leaks at idle, and then let us know what the real issue with the car is. Maybe we can help if we have something more than jumpy idle and black plugs.
Clean or replace those spark plugs, adjust the throttle position sensor, use some carburetor/throttle body spray to look for vacuum leaks at idle, and then let us know what the real issue with the car is. Maybe we can help if we have something more than jumpy idle and black plugs.
06-22-12, 07:21 PM
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Your right crappy idle isnt that big of a deal. More annoying than anything and it probably is because I deleted the thermowax and other stuff. My main concern is finding out where my air fuel mixture is because those numbers seem low. Also I do have a hot start issue, could that be because of the compression? Is 80psi to low, should I tear it down or do I have some time left.
someone else posted this for O2 sensor readings.
A specific O2 sensor voltage gives you a basic idea of your air to fuel ratio.
(Found the information below on a Datsun forum. It is still relevant, though.)
Volts > A/F ratio
.1 > 17:1
.2 > 16.5
.3 > 16:1
.4 > 15.4
.5 > 14.9
.6 > 14.4
.7 > 13.8
.8 > 13.2
.9 > 12.7
.985 > 12.1
My numbers are low does that mean I'm running rich or lean?
I have other stuff, but for now this is want I'm trying to find out.
someone else posted this for O2 sensor readings.
A specific O2 sensor voltage gives you a basic idea of your air to fuel ratio.
(Found the information below on a Datsun forum. It is still relevant, though.)
Volts > A/F ratio
.1 > 17:1
.2 > 16.5
.3 > 16:1
.4 > 15.4
.5 > 14.9
.6 > 14.4
.7 > 13.8
.8 > 13.2
.9 > 12.7
.985 > 12.1
My numbers are low does that mean I'm running rich or lean?
I have other stuff, but for now this is want I'm trying to find out.
06-22-12, 08:20 PM
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Reading about compression and testing it I realized I did not compress the gas pedal when testing my compression. Its raining right now so I'm not going to go out and check it again right now. But I'm curious how much of a difference it would make. If it is at 80 now how much would it go up with the throttle open? Enough to get my compression into the okay stage?
06-22-12, 08:47 PM
#6
Man, I really shouldn't get on forums after that much beer... I had a company golf tournament this morning, and I just now woke up from sleeping it all off.
Yes, I'm well aware how an O2 sensor works. It's a galvanic battery that actually creates a voltage as it measures the concentration of oxygen in exhaust. Typically, an O2 sensor will read up to about a volt, potentially a little more. When it goes to closed loop at idle, you're looking for fluctuations around .8, .9ish. If it's reading .05v and won't go any higher, that shows inactivity of the O2 sensor. Luckily, Mazda gave the Rx7 a simple single wire sensor, so they're good and cheap
So you have a hot start issue too? First off, let's start with the shitty idle thing. You should check the throttle position sensor for proper adjustment. There are TONS of instructions about doing so. First, set idle speed, then adjust the TPS. My favorite way is to backprobe the TPS connector (meaning shove the red lead inside to touch the metal clip) at the green/yellow wire, then touch the black meter lead to a ground. If it reads 1.000v at idle, good. If not, adjust until it reads such, blip the throttle a few times, let the idle settle out, then read it again. Repeat until you can snap the throttle, and each time it returns to 1.000v. If that doesn't take care of the shitty idle, spray some carburetor cleaner (or similar) around the intake manifold. If while you're spraying the idle increases and smooths out, you've hit a vacuum leak.
As for the hot start, check voltage at the ECU for the water thermosensor. The FSM has a pinout diagram, along with a voltage chart for every pin. My hot start issue turned out to be the thermosensor connector. It would plug in, but not make connection, therefore read 5v all the time.
But definitely clean or replace your spark plugs (I let them soak in degreaser and then brush them with a stiff toothbrush) and replace the O2 sensor. Then do all the above troubleshooting.
Yes, I'm well aware how an O2 sensor works. It's a galvanic battery that actually creates a voltage as it measures the concentration of oxygen in exhaust. Typically, an O2 sensor will read up to about a volt, potentially a little more. When it goes to closed loop at idle, you're looking for fluctuations around .8, .9ish. If it's reading .05v and won't go any higher, that shows inactivity of the O2 sensor. Luckily, Mazda gave the Rx7 a simple single wire sensor, so they're good and cheap
So you have a hot start issue too? First off, let's start with the shitty idle thing. You should check the throttle position sensor for proper adjustment. There are TONS of instructions about doing so. First, set idle speed, then adjust the TPS. My favorite way is to backprobe the TPS connector (meaning shove the red lead inside to touch the metal clip) at the green/yellow wire, then touch the black meter lead to a ground. If it reads 1.000v at idle, good. If not, adjust until it reads such, blip the throttle a few times, let the idle settle out, then read it again. Repeat until you can snap the throttle, and each time it returns to 1.000v. If that doesn't take care of the shitty idle, spray some carburetor cleaner (or similar) around the intake manifold. If while you're spraying the idle increases and smooths out, you've hit a vacuum leak.
As for the hot start, check voltage at the ECU for the water thermosensor. The FSM has a pinout diagram, along with a voltage chart for every pin. My hot start issue turned out to be the thermosensor connector. It would plug in, but not make connection, therefore read 5v all the time.
But definitely clean or replace your spark plugs (I let them soak in degreaser and then brush them with a stiff toothbrush) and replace the O2 sensor. Then do all the above troubleshooting.
06-22-12, 08:50 PM
#7
80 psi for a non-turbo is pretty low. Retry the compression check with the engine fully warmed up, both spark leading spark plugs removed, and throttle completely open. I use leading, some say use trailing... I don't think it really matters, but I still use the leading ones because the trailing has such a tiny little hole.
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06-22-12, 09:52 PM
#8
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Just so we are clear it is a turbo. Tomorrow or sunday I will do as you said with tps and thermo sensor, and I will recheck compression with throttle open. And it sounds as if I need a new O2 sensor so I'll get on that right away.
06-24-12, 07:42 PM
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Redid the compression test got 90 psi on both. Thats a little better. Put in the Walbro 255lph fuel pump and a new O2 sensor. The new O2 sensor read around
.9 and .8 when I would open the throttle. Cleaned spark plugs. As far as the tps goes I have two sensors that look pretty much identical. When I researched tps I only saw one sensor in that area. I'm assuming if I have two I should adjust both but not really sure on that one.
Took it out on the highway for the first time. Not bad, but definetely has some turbo lag. Step on the gas it will jump to about 4 psi on the boost gauge and then climb to around 8 or 9 psi. I'm assuming this is because my intercooler and piping are to big.
Havent messed with thermo sensor yet for that hot start issue, but I will get to that.
.9 and .8 when I would open the throttle. Cleaned spark plugs. As far as the tps goes I have two sensors that look pretty much identical. When I researched tps I only saw one sensor in that area. I'm assuming if I have two I should adjust both but not really sure on that one.
Took it out on the highway for the first time. Not bad, but definetely has some turbo lag. Step on the gas it will jump to about 4 psi on the boost gauge and then climb to around 8 or 9 psi. I'm assuming this is because my intercooler and piping are to big.
Havent messed with thermo sensor yet for that hot start issue, but I will get to that.
06-24-12, 09:23 PM
#12
Yours is S5, has a narrow range and wide range tps. The wide range is used for the oil metering pump, and the narrow range is pretty much only for idle and light throttle operations. Don't ask me which one... I've never owned or messed with an S5. Do an advanced search, titles only, for %S5 TPS (yes, use the % sign).
06-26-12, 10:18 PM
#13
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Just to compare I went ahead and put the stock intercooler back on with stock intake and bypass valve.Couldnt get boost to go up as high as it was with the FMIC. And also it seemed like it was cutting out at 6psi of boost, almost like fuel cut but it was rapidly backfiring until I took my foot off the gas. I turned up the manual boost controller but didnt make a difference with a couple turns. I'll try turning it up more and trying some runs, but I'm surprised it did worse with the SMIC. I was under the impression it is good for atleast 10psi.
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