Replaced the alternator so now voltage is strong.
Checked the clutch switch, it is extending completely - not sticking.

Car will start, idle at 750 with ac off.
But if you just let it sit there, maybe 5 minutes until it will sputter and stall.
Same effect if it has been driven then parked to idle.

When driving, car is prone to stall at low rpm or at red lights.

Fuel filter is good. Plugs are new.

Backfiring is getting progressively worse especially when slowing down in say 2nd.

Checked for vacuum line issues, everything seems tight.
Map sensor is plugged in.

Thinking about raising the idle -- But, it should be able to sit at 750 and idle all day, right?

Thanks for any insight.

 

Have you checked the dash pot on the throttle body? That can cause stalling when coming to a light. Easy thing to check.

Dale

 

Dale,

Checked the Dashpot -- might be the culprit.
1. plunger only extends 1/8 inch -- I cleaned it but it still only does 1/8th.
2. You can grab it and pull it all the way out BUT, that's only 1/4 inch
3. it's not sticky, it is springy

could it have broken off at some point, thought it was supposed to be longer

Is there any adjustment to move the plunger out farther? I don't see any.

 

Dashpot might be the root cause but you haven't provided a list of engine modifications and you haven't given a very specific description of exactly when the engine cuts off.

 

arghx,

Car is stock.
Fresh rebuild with New Housings and New Engine Wiring Harness

stock ECU
downpipe
aluminum AST
Cold air intakes

Problem is with stalling at red lights and backfiring (more and more) while decelerating.

Thanks

 

Try the idle adjustment procedure in the service manual:



The reason why I say this is because the dashpot is only one aspect of the deceleration system. The idle speed control valve works in conjunction with the amount of bypass air through the throttlebody.

 

Thanks, I'll keep trying.

 

I'm having this exact problem with similar mods. Did the idle adjustment procedure fix the problem?

 

Replaced the dashpot, that was One of the problems.
Ran it all the way down until low fuel light came on == for some reason, that
also helped.

Backfiring is still an issue, but not nearly as bad and car does Not stall now.

 

I've had an issue similar to this before. I had a new engine put in, build by Atkins rotary, and it would be hard to start, die and back fire a lot. It ended up being that the engine was badly assembled/built. I sure hope this isn't the case for you. Have you checked engine compression?

 

I'd check your TPS if you haven't already.