Starts and dies right away 90TSI

[theox1010]

I am an old muscle car guy that needs some help with diags on my son’s 90 Talon TSI 4g63. He is away at school and I told him I would drive the car once a week or so to keep it fresh (and have some fun). Problem is it won’t start. It has been sitting idle for a few weeks and It cranks, fires right up and runs a couple revs then dies. I have looked at normal things like fuses, connectors and relays but all look good. The ECU is putting out a normal code (on off on off) does that mean it is ok? Spark appears normal. I did monitor the CAS at the connector and it seems to be putting out a signal train on two leads. I have jumped the fuel pump at the test connector and can hear it run but do not know if it is really pumping at the correct pressure. Seems like I used to hear the fuel pump run when the key was first turned to on but I no longer hear it. I do hear it run a little after when the engine dies. Would appreciate any suggestions on where to look next.

 

[krisj144]

I'd really like to hear an answer for this guy because my gsx seems to be doing the same thing. C'mon somebody, fix two cars with one solution!

 

[Raph]

and your son didnt loosen the negative terminal or something and didnt tell you? go check that.

 

[theox1010]

Last thing my son did was to try and install one of those strut braces and drew a nice arc on the Battery connectors. I cleaned all terminals and they look

 

[92awddsm]

Am I correct in assuming this just happened without warning? Any odd smell or odors in the car? Any clicking or buzzing noises in the console behind the radio? Pull the ecu, remove the cover and check for leaking capacitors or a damaged circuit board.

 

[Old Mitsu Tech]

It could be several things. Being a 90 and all, and with the arcing on the battery I might take a look at the pcm. At least give it the smell test to see if it has had the smoke let out of it. I've seen pcm's, cam angle sensors, igniters and all give problems. Mostly the pcm's especially in your case. Might borrow one to see if it could be the source of the problem. If it won't start, use a test light and probe one of the injector wires. If it shows hot with the key on, then that part is at least ok. Now hook the light to the pos side of the battery and probe the "other" wire on the injector. Does it flicker? Steady or no light means pcm "computer" problems.

Let us know.

 

[steve]

If you leave the fuel pump powered up via the test connector does the car stay running?

One symptom of capacitor leakage damage is the ECU not being able to feel the fuel pump running after the starter circuit primes the fuel system during starting,

Steve

 

[theox1010]

thanks for replys - does not run with fuel pump jumped. I will try the injector thing and smell or look at the ECU and will let you know.

 

[Rex2342]

Not that it's much help but in my 90 I don't hear the pump when I turn the key on. I tested an ECu once that I thought might be bad and it did something similar to this. It started once and died but wouldn't start again. With the arcing you should also check the fuse box on the positive battery terminal. I arced my alternator on my lower IC pipe once and it blew one of those fuses. I can't remember exactly which one but it was in that box.

 

[theox1010]

Pulled the ECU and opened it up. Does not smell bad but there is some black goo around one of the capacitors. Does any one repair ECUs? What are my options here?

 

[92awddsm]

Contact steve who posted above. He does ecu repairs.

 

[theox1010]

Steve truly is the DSM Wiseman! I bow to the GURU of ECUs. The Talon lives again – Problem was the leaking caps in the ECU. Steve repaired my CPU and it works great – this thing is scary fast. Thanks for all the help. I will be back