Same Car, Different Problem

[LightningAclhemist]

It's me again, the Bonnie owner with a Rebellious Bonnie.

Here's her story, again:

Previous owner seized the engine seven-eight years ago. Sat under a tree for four years. Three years ago, she was sold to my dad and we got her running again with a '98 engine. The check engine light was on, and nobody could read the code. It was the Knock sensor, and we replaced both sensors with 95 sensors. No more light until ...

Hard Stumbling, misfiring, Refusing to run nicely on occasion if she started. Turned out to be the heavy keychain. Problem solved, right?

For two months, no more problem. Then she started stumbling and misfiring again if she started (About 3/5 times she'd start). With an inconsistant check engine light. When I thought she had a solid light, I took her in and there was no light.

What she does:
Turns over, acts like she starts, then dies immediately. Regardless if your foot is on the throttle or not. Pumping the throttle doesn't work. Yes, the fuel pump starts and hums, so it's unlikely to be that. She also seems to have the most problem with short trips/runs. Getting up to operating temperature and turning off, or running for about fifteen minutes at op. temp.

Here's a link to the video that I made of this issue: https://www.youtube.com/watch?v=Pn8ugcJ3lJ8

I've replaced on this car since I got her:
Engine (120k miles with a ~150k miled one)
O2 Sensor (five times since I've had her. It seemed to work for a little while.)
Crankshaft Sensor (~133K)
Knock sensors, fixing the check engine light (~137K)
Mass Air Flow (~145k)
BG44K Fuel System Cleaner (~146,700)
Fuel Filter (147k)
Regular oil changes (Just did one at 150k)
Air Filter (just replaced it not even 200 miles ago)

What I haven't done:
Temperature Sensor
Idle Air Control
Throttle Position Sensor
Spark Plugs and Wires (Test or replace)
Fuel Injectors
Fuel Pump

I would greatly appreciate it if you could help me with this problem! I've done so much on this car to have her not work like this!

[Barry]

It seems to me that you have an electrical (ignition) problem. I'm not sure how to test for it, but I think someone else will chime in. It may need a new ignition switch.

[MattStrike]

That acts a lot like a security issue. I know you said the fuel pump is working; you might try bypassing the fuel pump relay and using a 194 light bulb in one of the fuel injector connectors to see if the pcm is cutting fuel.
The VATS module might be working, but not sending the signal to the pcm. There is a smaller single ground wire connector right next to the battery terminal, check that first. Beyond that I don't have the '95 CSM to tell you where the other grounds are.

[LightningAclhemist]

I just checked that connection. It looks a little corroded and dirty, but it's solid. Any ideas on how to clean it?

[MattStrike]

Electrical contact cleaner and a silicone based grease to seal it against further corrosion, also check that the corrosion has not caused the contacts to spread and making intermittent connection. Other option is to splice in a new connector if it's too far gone.

[LightningAclhemist]

I disconnected the battery and cleaned that little contact. I have good news, bad news, and worse news.

Worse news: Still not starting.
Bad news: The Check Engine Light in that video? Not there anymore.
Good news: I think I found a device that would bypass the VATS and help my car to start? I'm going to do more research on it. A link to the device: http://www.bakerelectronix.com/products_vats/

All things seem to be pointing toward the VATS ... Oh, the joys of electrical systems.

[RJolly87]

The only concern with those devices is that you will need to bypass the starter interrupt that the VATS also has control of, but that should prevent any more issues arising from the VATS. You basically put that in place of the VATS module to the PCM, and it just gives the all clear signal all the time.

[LightningAclhemist]

Which seems to be my best option right now. I'll have to double-check to make sure it's the thing I need before I do anything else. Thanks! I'll put up an update when I can, which might not be for a little while.