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The car used to start and die about 4 seconds after but I jumpered the fuel pump socket and now it does this. There are no major vacuum leaks that I can find and. the car runs relatively normal as you can hear in the video after it gets good and running. I just don't understand why it's dying like this. I give it gas when it starts but when it stalls the throttle has no effect.

Any ideas?

 

Paging hailers

 

It sounds really good once it smooths out... then it just dies.

 

Directly next to the water thermo valve, about an inch more toward the driver side, there is a hose coming off and I can't see where it would go... I can take a picture if that would help.

 

No one can help?

 

Is it really this big of a mystery? Can anyone recognize this behavior?

 

AFM plug ok?

 

It's disconnected. I have the fuel pump jumpered.

What else could make it stall like that?

 

i have the exact same problem on my SE, at first i thought it was the fuel filter or the ignition switch itself, but after swapping the filter and playing with some wiring i think the problem lays with either the TPS or ECU.

i always have a spare AFM that i swapped in, no change. weird....

 

I figured out that it is in fact a fuel problem. I sprayed some starter fluid in and it will run on the fumes. I am going to get the injectors rebuilt and see if that fixes it.

 

Plug it back in, and keep the fuel pump jumpered..

 

I have observed similar symptoms on my 86 when the BAC valve connector was disconnected. It would start and run for a couple of seconds, but when it tried to settle down to normal idle it would oscillate up and down and finally die.

Check that the BAC valve connector is connected; check the BAC valve per the FSM procedure (listen for a click when 12v applied); check the BAC valve control voltage per the FSM at the appropriate pin on the ECU.I

I thought I heard some backfiring in your video, which would suggest a too rich mixture. Very similar to what I observed, especially the inability to start it after the stall (sounds like its flooded).

 

It's definitely not flooding. The plugs are dry and deflooding thoroughly has no effect on the starting. I know I have a massive vacuum leak at the injector(s) and I have no BAC valve. I also found that the thermo sensor plug behind the alternator was unplugged. I'm not sure if that could cause my problem.

 

How would that help? I thought that jumpering the fuel pump just bypassed the afm. I'll do that tomorrow.

 

You need the AFM plugged in to keep the car running.

 

What's the point of jumpering the fuel pump then?

 

It won't idle without a BAC valve, unless you find some other way to provide bypass air in sufficient quantity to allow it to idle.

The massive vacuum leak will cause it to run too lean, especially at idle, and die.

The disconnected water thermo valve will cause the ECU to believe the start is being conducted under extremely cold conditions; high (aka infininte) resistance of the water thermo sensor corresponds to low temps. The ECU richens the mixture to compensate for the low temps. This probably compensates for the lean condition created by the 'massive vacuum leak' above a certain rpm, and is insufficient enrichment to compensate for the leak at low rpm/high vacuum.

Fix the vacuum leak(s).

Connect the water thermo sensor, and check the voltage at the ECU per the FSM, see to it that it is within limits.

Replace the BAC valve, and hook it up.

Check the AWS air bypass solenoid, and make sure it is hooked up properly.

 

Got the BAC valve connected and working. It idled for about 40 seconds then choked out. I think that if I get the AFM and the water temp in working order and get the injectors worked over it will fix my problem. I'll post another video when that stuff is finished.

 

Because on occasion the FC AFMs are known to fail on the fuel pump interlock section of the AFM. You still need it to run the car though, it meters the air as well.

 

Fuel pumps go out. Mine would run for 30-60 seconds then cut out when mine went. have someone in back with a voltage meter.. If the pump stops the voltage spikes. You would see if it was the fuel pump that is stalling out.

Or listen to the pump. and make sure it keeps running with the car off, Since you have it jumped

 

I see ty.

Yeah. That was the first thing I checked. I'm pretty sure it's a combination of the vacuum leak at the injectors and the thermo sensor being unplugged. We will see when the injectors get back. I'll post another video. I also removed the cat, so there won't be any restriction there.

 

How was the idle before it died? High? Low? Consistent or jumpy?

If you know you have a "massive vacuum leak" then that's the first thing you need to fix.