Resolved 90 Car keep shutting off.

[U8NTRDY]

Sup Guys,
I just picked up my second DSM. Its a 90 Talon TSi. The problem is that when I start it, it will start without hesitation, then run flawlessly for a minute or two then all of a sudden just die... so far I've replaced the alternator, battery, fuel pump, alternator relay, and checked the alternator fuse... any suggestions?

 

[russell3123]

get a haynes manual and check the ohms on the cam angle sensor and coil. or open it up and try cleaning it first.. sometimes oil leaks in

 

[Nasty Dream]

For starters, I would change the PCV valve. It's probably older than Moses.

That's my new first step for idle problems

-Rough idle
-stalling

etc

only about $3.50

 

[U8NTRDY]

get a haynes manual and check the ohms on the cam angle sensor and coil. or open it up and try cleaning it first.. sometimes oil leaks in

hmm.. Do you think the CAS could be causing this issue? I've had trouble with them before in my eclipse but every other time I've had any type of problem with the CAS, the car wouldn't start at all. Now the car starts but only runs for about a minute before stalling out.. I will still take your advice and do the above though. ya never know.. Thanks for the tip

For starters, I would change the PCV valve. It's probably older than Moses.

hahaha Ok I will try to replace it and see what happens

 

[Nasty Dream]

Especially because you say it's fine and then stalls after some time. This is something new to me, but fumes build up if it is clogged (PCV valve is to vent that), and that could trigger it. Something I was reading about the computer keep having to adjust. So that could make your car stall.

If it does fix it, you will want to check for sludge under the valve cover, because it could be bad in there if it was clogged.

But, just one idea. I'm sure the others have better ideas you can try.

 

[Calan]

The PCV valve won't cause the car to run and then die. (Actually, I've never seen a car completely stall or not start because of a fubared PCV valve, no matter how bad...but anything is possible I guess . Still doesn't hurt to replace it though, along with adding a check valve and improving the crankcase ventilation system in general.

It sounds to me like the car is dying once it drops into closed loop, which points to the front O2 sensor being bad.

Since you have ECMLink, post up a log. Check to see if the front O2 is cycling, and log OpenLoop (or ClosedLoop) and see if it switches right when the car dies.

 

[U8NTRDY]

The PCV valve won't cause the car to run and then die. (Actually, I've never seen a car completely stall or not start because of a fubared PCV valve, no matter how bad but anything is possible I guess . Still doesn't hurt to replace it though, along with adding a check valve and improving the crankcase ventilation system in general.

It sounds to me like the car is dying once it drops into closed loop, which points to the front O2 sensor being bad.

Since you have ECMLink, post up a log. Check to see if the front O2 is cycling, and log OpenLoop (or ClosedLoop) and see if it switches right when the car dies.

The front o2 being bad is a very possible reason that I hadn't previously thought of. I do have ECMLink v3 in my GSX but the TSi is pretty much stock aside from an MBC, exhaust, and SAFC II. So unfortunately I won't have the luxury of datalogging on this one... but then again it might be worth saving all my tune info from the GSX and doing a temporary ECU swap to get this situation figured out.

 

[Nasty Dream]

But if the o2 sensor was bad, wouldn't you get a CEL?

BTW, what happens after it stalls? Does it start back up again and do the same thing, or do you have to wait a while?

 

[kchaazz]

I say large vaccum leak between throttle body and intake manifold, between intake manifold and head, or the blow off valve. If someone replaced the throttle body to intake manifold gasket, Id check to be sure the right gasket was used because there is a very big diferrence between the 90 gasket, and the 91+ gasket and the parts slingers almost always give ya the 91+ thinking its the correct one.

 

[U8NTRDY]

But if the o2 sensor was bad, wouldn't you get a CEL?

BTW, what happens after it stalls? Does it start back up again and do the same thing, or do you have to wait a while?

I don't have a CEL while the car is running fine but the CEL does come on as the car is starting to stall out.

As for what happens after it stalls. Usually right after the first time it stalls you can start it back up but it stalls back out much faster the second time (almost immediately). After restarting and stalling a few times in a row, the car will continue to crank strong but won't start until you wait a little.

I say large vaccum leak between throttle body and intake manifold, between intake manifold and head, or the blow off valve. If someone replaced the throttle body to intake manifold gasket, Id check to be sure the right gasket was used because there is a very big diferrence between the 90 gasket, and the 91+ gasket and the parts slingers almost always give ya the 91+ thinking its the correct one.

I just got this car but I am good friends with the previous owner. No gaskets have been tampered with or replaced. The car was running great without any issue. Then the car sat for about two weeks, and the battery died. The car was jump started and this problem started happening from that moment on. I've already checked for vacuum leaks and did find a leak from the head to intake but that did not fix the problem. Next time I look at it, i'll be double checking a few other key places

 

[kchaazz]

I bet the CEL, if you pull the code, will be for the MAF, or the coolant temp sensor. If it is for the MAF, then there is definitely a nice vacuum leak. Do you have access to a boost leak tester?

Could also be that the CEL is just coming on cause the car's dying, which can be normal without any codes. Does the car "fast" idle when you start it with a cold motor?? (1000- 1200 rpms)

 

[U8NTRDY]

I bet the CEL, if you pull the code, will be for the MAF, or the coolant temp sensor. If it is for the MAF, then there is definitely a nice vacuum leak. Do you have access to a boost leak tester?

Could also be that the CEL is just coming on cause the car's dying, which can be normal without any codes. Does the car "fast" idle when you start it with a cold motor?? (1000- 1200 rpms)

I could get access to a boost leak tester. The CEL doesn't come on unless the car is in process of stalling out. Other than that there is no light and when you restart the light is gone. The car does idle slightly high until it gets close to normal operating temp then drops down to about 750-800.

 

[Calan]

The front o2 being bad is a very possible reason that I hadn't previously thought of. I do have ECM Link v3 in my GSX but the TSi is pretty much stock aside from an MBC, exhaust, and SAFC II. So unfortunately I won't have the luxury of datalogging on this one... but then again it might be worth saving all my tune info from the GSX and doing a temporary ECU swap to get this situation figured out.

Just swap the O2 sensor if you know the one in the GSX is good.

 

[U8NTRDY]

Just swap the O2 sensor if you know the one in the GSX is good.

Unless I'm mistaken, won't work.. In the GSX I have my WB in the front location with ECMLink running NB Sim. Based on all the info presented, are you leaning towards the o2 sensor?

Thanks for all the input so far, its greatly appreciated. I'm sure you guys know well how frustrating something like this can get.

So far on the checklist:
Double checking all vacuum lines,
Swap the PCV,
Test for boost leaks,
Check the CAS,
Swap out the o2 sensor

 

[6bolt4g63]

Why isnt check for codes on your list?

 

[U8NTRDY]

Why isnt check for codes on your list?

Because currently there is no CEL, it only comes on when the car is dying then disappears when you restart the car..

 

[6bolt4g63]

Check it, its easy.

 

[POS_Tsi]

The ECU should store the code so you can still pull it

 

[U8NTRDY]

Check it, its easy.

The ECU should store the code so you can still pull it

Ok cool, I'll check and see what code it gives me. I didn't know the code would still be there even without a CEL. Thanks guys.


UPDATE: Today I swapped the PCV and still had the same issue. I swapped the ECU with my ECMLink V3 ECU from my Eclipse and like magic the car ran fine. I can only assume something was wrong with the ECU. Not sure exactly what though. Thanks for all the help!