TII Swap Won't Start, My Compression ok? (Videos inside)
05-01-11, 12:02 PM
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TII Swap Won't Start, My Compression ok? (Videos inside)
I swapped in an S4 13BT motor this last week into my S4 N/A. This thing will not start and run. It will crank over and once in a blue moon will catch for a sec, but thats about it. I am getting spark from the leading Coils, and the plugs are covered in fuel so I know I'm getting that. Also, Vacuum leaks seem to be non-existant. I have searched through the forum non stop for a week.
My injectors were apparently cleaned before my purchase, fuel lines are hooked up correctly, as are all vacuum lines, except brake booster (which I think the PO blocked off before giving me the engine). Have tried hooking up other ECU's, checked to see if i switched the injector plugs, Have deflooded the hell out of the car time and tme again. Also had 0 luck with the ATF trick which I tried 3 times. I dont want to put any more money into the swap if it's blown.
Here are videos from my compression tests yesterday, I performed 2 for each housing. On the second test for each housing, when my finger was off the pressure release button, they scored at about 100. Maybe that can help for reference because of the quality.
Front Rotor Housing, 1st Test
<iframe width="480" height="390" src="http://www.youtube.com/embed/46zpmyMEks4" frameborder="0" allowfullscreen></iframe>
Front Rotor 2nd Test
<iframe width="480" height="390" src="http://www.youtube.com/embed/OxmI9aRXcE4" frameborder="0" allowfullscreen></iframe>
Rear Rotor 1st Test
<iframe width="480" height="390" src="http://www.youtube.com/embed/Gqfl98RegxA" frameborder="0" allowfullscreen></iframe>
Rear Rotor 2nd Test
<iframe width="480" height="390" src="http://www.youtube.com/embed/xBYPy-hmSy8" frameborder="0" allowfullscreen></iframe>
My injectors were apparently cleaned before my purchase, fuel lines are hooked up correctly, as are all vacuum lines, except brake booster (which I think the PO blocked off before giving me the engine). Have tried hooking up other ECU's, checked to see if i switched the injector plugs, Have deflooded the hell out of the car time and tme again. Also had 0 luck with the ATF trick which I tried 3 times. I dont want to put any more money into the swap if it's blown.
Here are videos from my compression tests yesterday, I performed 2 for each housing. On the second test for each housing, when my finger was off the pressure release button, they scored at about 100. Maybe that can help for reference because of the quality.
Front Rotor Housing, 1st Test
<iframe width="480" height="390" src="http://www.youtube.com/embed/46zpmyMEks4" frameborder="0" allowfullscreen></iframe>
Front Rotor 2nd Test
<iframe width="480" height="390" src="http://www.youtube.com/embed/OxmI9aRXcE4" frameborder="0" allowfullscreen></iframe>
Rear Rotor 1st Test
<iframe width="480" height="390" src="http://www.youtube.com/embed/Gqfl98RegxA" frameborder="0" allowfullscreen></iframe>
Rear Rotor 2nd Test
<iframe width="480" height="390" src="http://www.youtube.com/embed/xBYPy-hmSy8" frameborder="0" allowfullscreen></iframe>
05-01-11, 12:28 PM
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you are not correctly checking your compression..
You need to remove the schrader valve in the tip of the guages hose or u can hold the release valve
then watch for 3 individual bounces
You need to remove the schrader valve in the tip of the guages hose or u can hold the release valve
then watch for 3 individual bounces
05-01-11, 12:53 PM
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compression only seams to be around 60 in the rear but its really hard to tell with the quality..
front seemed about the same but more stable..
are you sure the crank angle sensor is coreectly stabbed?
how are u deflooding it?
front seemed about the same but more stable..
are you sure the crank angle sensor is coreectly stabbed?
how are u deflooding it?
05-01-11, 02:32 PM
#6
A little help
.
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/rotary-compression-tester-734840/
Here is jackhild59's methodology for uniform compression test results on a rotary engines
Fully charge the battery. Slow rotation will yield deceptively low results.
Use the bottom spark plug hole; take both bottom spark plugs out for the duration of the test.
Remove the EGI fuse: you don't want the thing trying to try to run.
The throttle should be held to the floor or the throttle plate tied fully open. Failure to do this will yield very low results.
You will need an assistant to operate the ignition (and throttle) or a remote start switch with the throttle tied open.
Ideally the test should be done while the engine is warm. Cold is ok, but warm numbers are what should count. If you test a cold engine, be aware the what looks like an unacceptably low number may actually turn out to be quite all right. There is no hard fast number that will be the difference from cold to hot. Warm will be consistent, cold may not be. If an engine fails the test cold, it may well pass the test when warm.
Crank the engine for about 10-15 seconds max for each test.
Bump Test:
This verifies that the apex seals are operating properly, ie. not broken or stuck.
Remove the Schroeder valve in the BOTTOM of the compression tester (NOT the side release valve) for the 'look for three uniform bump test'.
Leave the side release valve alone for this test.
Test each chamber front then rear, make notes! Those bumps should be even and somewhere around 60-70 psi minimum.
Compression Test:
This is to test the actual compression in the engine.
Replace the Schroeder valve in the BOTTOM of the compression tester.
Retest each chamber, this time allowing the pressure to pump up to the maximum psi. Write this number down.
PSI should be above 85 psi per the FSM. Lower than this and the engine is in need of a rebuild. This engine will be prone to flood. It may however run for quite sometime, especially if it is NA.
90 psi+ should be enough to run reliably;
95 psi + is great,
100psi+ is excellent.
NOTE: All pressures will tend to be lower with longer hoses and higher with shorter hoses. Experts agree that ideally, the hose should be as short as possible; Best would be if the hose were eliminated and the unit screwed directly into the sparkplug hole essentially with the gauge as closely coupled to the compression chamber as possible.
NOTE 2: In general, Turbo II's will be lower numbers than NA, S4's will be lower than S5's.
NOTE 3: This write up is a compilation from several authors, Reted, Kevin Landers, Aaroncake and others combined, clarified and hammered into one place. The intent is to create consistent documented methodology in one place so that the newbs and accomplished alike can agree on the results.
Here is jackhild59's methodology for uniform compression test results on a rotary engines
Fully charge the battery. Slow rotation will yield deceptively low results.
Use the bottom spark plug hole; take both bottom spark plugs out for the duration of the test.
Remove the EGI fuse: you don't want the thing trying to try to run.
The throttle should be held to the floor or the throttle plate tied fully open. Failure to do this will yield very low results.
You will need an assistant to operate the ignition (and throttle) or a remote start switch with the throttle tied open.
Ideally the test should be done while the engine is warm. Cold is ok, but warm numbers are what should count. If you test a cold engine, be aware the what looks like an unacceptably low number may actually turn out to be quite all right. There is no hard fast number that will be the difference from cold to hot. Warm will be consistent, cold may not be. If an engine fails the test cold, it may well pass the test when warm.
Crank the engine for about 10-15 seconds max for each test.
Bump Test:
This verifies that the apex seals are operating properly, ie. not broken or stuck.
Remove the Schroeder valve in the BOTTOM of the compression tester (NOT the side release valve) for the 'look for three uniform bump test'.
Leave the side release valve alone for this test.
Test each chamber front then rear, make notes! Those bumps should be even and somewhere around 60-70 psi minimum.
Compression Test:
This is to test the actual compression in the engine.
Replace the Schroeder valve in the BOTTOM of the compression tester.
Retest each chamber, this time allowing the pressure to pump up to the maximum psi. Write this number down.
PSI should be above 85 psi per the FSM. Lower than this and the engine is in need of a rebuild. This engine will be prone to flood. It may however run for quite sometime, especially if it is NA.
90 psi+ should be enough to run reliably;
95 psi + is great,
100psi+ is excellent.
NOTE: All pressures will tend to be lower with longer hoses and higher with shorter hoses. Experts agree that ideally, the hose should be as short as possible; Best would be if the hose were eliminated and the unit screwed directly into the sparkplug hole essentially with the gauge as closely coupled to the compression chamber as possible.
NOTE 2: In general, Turbo II's will be lower numbers than NA, S4's will be lower than S5's.
NOTE 3: This write up is a compilation from several authors, Reted, Kevin Landers, Aaroncake and others combined, clarified and hammered into one place. The intent is to create consistent documented methodology in one place so that the newbs and accomplished alike can agree on the results.
05-01-11, 04:03 PM
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As far as the quality, I apologize. My cell phone was the best I had at the time. In each of the "step two" videos where the compression was allowed to build and stay, each reached about 100 psi before stopping. Maybe that can help as far as referencing the needle on the bounces. I deflooded using the EGI fuse pull and cranking with the throttle down method. I had to do it once and a while with my N/A and had it work successfully. As for the CAS, I had a buddy of mine walk me through the setting process, and the dimple was lined up with the notch when I inserted it back into the front cover. Should be fine.
Also let ATF sit in each leading spark plug hole overnight and cranked it over slowly by hand a couple times after putting it in. Thing didnt even want to push start. It only started when we towed it behind my friends truck.
Also let ATF sit in each leading spark plug hole overnight and cranked it over slowly by hand a couple times after putting it in. Thing didnt even want to push start. It only started when we towed it behind my friends truck.
Last edited by Insomnium; 05-01-11 at 04:08 PM.
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05-01-11, 07:19 PM
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i am having the same problems. getting spark, fuel, grounded properly, new battery, good alternator, new spark plugs, main relay is working, afm working, tps working, etc....everything is working properly but when i try to start it, it drains the battery. then, when i pull out my plugs, they are soaked and dont even look like they are sparking even though i am getting spark on all 4 tips of the coil packs. crank sensor works, omp works (i have 2 so i know they work good).
i have not tested the starter- turns the engine over (could there be a solenoid voltage drain?)
maybe this will help narrow things down for the OP and help me as well at the same time.
i even checked every single pin connection at all connectors and everything looks to be connecting properly.
i have not tested the starter- turns the engine over (could there be a solenoid voltage drain?)
maybe this will help narrow things down for the OP and help me as well at the same time.
i even checked every single pin connection at all connectors and everything looks to be connecting properly.
05-01-11, 07:35 PM
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i am having the same problems. getting spark, fuel, grounded properly, new battery, good alternator, new spark plugs, main relay is working, afm working, tps working, etc....everything is working properly but when i try to start it, it drains the battery. then, when i pull out my plugs, they are soaked and dont even look like they are sparking even though i am getting spark on all 4 tips of the coil packs. crank sensor works, omp works (i have 2 so i know they work good).
i have not tested the starter- turns the engine over (could there be a solenoid voltage drain?)
maybe this will help narrow things down for the OP and help me as well at the same time.
i even checked every single pin connection at all connectors and everything looks to be connecting properly.
i have not tested the starter- turns the engine over (could there be a solenoid voltage drain?)
maybe this will help narrow things down for the OP and help me as well at the same time.
i even checked every single pin connection at all connectors and everything looks to be connecting properly.
05-01-11, 07:59 PM
#10
No. Additionally, have you tried to start the car using starter fluid with the fuel pump unplugged? Your plugs being soaked in fuel is a recipe to fouled plugs. You need to attempt to rid the flooding problem to a point where the plugs are not in jeopardy of being flooded.
05-01-11, 08:28 PM
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Sometimes it'll get a tooth off if you touch the edge of the front cover as you put it in. Sometimes they like to jump a tooth as you hit the eccentric shaft drive gear.
Best bet is to have the cover off the CAS and hold it steady as you insert it.
05-01-11, 08:56 PM
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Should being the operative word.
Sometimes it'll get a tooth off if you touch the edge of the front cover as you put it in. Sometimes they like to jump a tooth as you hit the eccentric shaft drive gear.
Best bet is to have the cover off the CAS and hold it steady as you insert it.
Sometimes it'll get a tooth off if you touch the edge of the front cover as you put it in. Sometimes they like to jump a tooth as you hit the eccentric shaft drive gear.
Best bet is to have the cover off the CAS and hold it steady as you insert it.
I am using low impedence injectors ( 2 550 primaries and 2 680 FB secondaries) and the wiring harness I purchased had a hook up for my resistor box located under the air intake as well, so I am assuming thats all good. Using a Walbro 255 as well... could it be an FPR issue?
Last edited by Insomnium; 05-01-11 at 08:59 PM.
05-02-11, 07:00 AM
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^
Disconnect the fuel injectors, dry off the plugs (Crank it without the plugs to clear out any fuel.)
Try again with the starting fluid.
Also see of you're getting electrical pulses to the fuel injectors.
You might be getting TOO MUCH fuel from the injectors. One might be stuck open or something.
Disconnect the fuel injectors, dry off the plugs (Crank it without the plugs to clear out any fuel.)
Try again with the starting fluid.
Also see of you're getting electrical pulses to the fuel injectors.
You might be getting TOO MUCH fuel from the injectors. One might be stuck open or something.
05-02-11, 10:29 AM
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^
Disconnect the fuel injectors, dry off the plugs (Crank it without the plugs to clear out any fuel.)
Try again with the starting fluid.
Also see of you're getting electrical pulses to the fuel injectors.
You might be getting TOO MUCH fuel from the injectors. One might be stuck open or something.
Disconnect the fuel injectors, dry off the plugs (Crank it without the plugs to clear out any fuel.)
Try again with the starting fluid.
Also see of you're getting electrical pulses to the fuel injectors.
You might be getting TOO MUCH fuel from the injectors. One might be stuck open or something.
05-02-11, 10:35 AM
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Well, I also meant for you to try starting it without the fuel injectors and get it to run solely on the starting fluid...
What I'm suspecting is happening is that either an injector is stuck open or constantly getting power. The engine first tries to fire off, then gets flooded out due to too much fuel.
What I'm suspecting is happening is that either an injector is stuck open or constantly getting power. The engine first tries to fire off, then gets flooded out due to too much fuel.
05-02-11, 10:36 AM
#16
If you crank the engine with the plugs pulled to dry out the housings w/o disabling the injectors in some manner then you won't be able to deflood the engine if it is indeed flooded. Have you also disabled the injectors/fuel system in the process of trying to deflood?
05-02-11, 10:36 PM
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Update-
Today I tried switching wiring harnesses and plugged up two more vacuum leaks I found, still no luck on getting it to start though.
Plan on trying some new injectors tomorrow, we'll see how that goes.
So what is this fuel pump relay I keep hearing I need to jump?..
Today I tried switching wiring harnesses and plugged up two more vacuum leaks I found, still no luck on getting it to start though.
Plan on trying some new injectors tomorrow, we'll see how that goes.
So what is this fuel pump relay I keep hearing I need to jump?..
05-03-11, 04:52 PM
#20
Does it run even (smooth)? No, because it's dead.
I keep seeing users posting compression vids of the needle test and they dont know what they're looking for. It's real simple. Remove the leading plugs. Remove the EGI fuse. Hold the gas pedal to the floor to open the TB and crank the engine for 10 seconds. It goes PSHT PSHT PSHT PSHT PSHT PSHT it's good. Anything other than 6 even PSHT noises and the engine needs to be opened up and rebuilt.
The compression tester is to see the 3 even pulses of air each rotor will push out of the plug hole. You need to hold that button while you watch the needle bounce.
If you have PSHT PSHT PSHT PSHT PSHT PSHT then it will run without you having to hold the pedal to the floor.
This is also why I would never take the time to swap an engine without opening it up and inspecting the internals. Even if there is nothing wrong, for the cost of a gasket kit you can clean the 20+ years of carbon buildup off the rotors and seals and swap anything that isn't within specs.
05-03-11, 11:47 PM
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Tried your method today and everything sounded consistent I heard an apex seal is one strong and 2 weak, so even if my engine did have a side seal stuck, which i heard is one weak 2 strong, it must be unstuck now. Wish I tried your method from the get go, much easier. Thanks for the help.
05-04-11, 12:33 AM
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Didn't have the chance to rent a tester today, but by ear everything sounded consistent. Compared it to Aaroncake's sound clip of a blown engine on his website and my compression pulses were much closer together. Same on each rotor housing.
Assuming at this point that it's a TPS problem, will reinstall my old N/A one tomorrow.
Would I need a TII Fuel Sending unit? im currently running a walbro 255 in the old NA unit.
Assuming at this point that it's a TPS problem, will reinstall my old N/A one tomorrow.
Would I need a TII Fuel Sending unit? im currently running a walbro 255 in the old NA unit.
05-04-11, 09:39 AM
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Not to hijack, but what's the resulting difference of doing the compression test from the trailing vs the leading plug?
I ask because when I did it, I used the trailing, but you guys are saying to use the leading. Wondering if I should redo it?
I ask because when I did it, I used the trailing, but you guys are saying to use the leading. Wondering if I should redo it?
05-04-11, 11:20 AM
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I used the trailing in the video above too, but when I went back I used the leading. I just redid it with the leading to stay consistent with the info I was getting in different threads.