Car dies when throttle is pressed.

[hotrod406]

Hi, I'm new to the forum, but have been lurking for a while.

 

My 95 cutlass 3100 has a problem that I can't figure out. It starts okay and runs for a while, but after 5 minutes or so it will die when the throttle is opened quickly. The motor will accelerate if I open the throttle very slowly, but anything quick kills it. It runs pretty rich too, black smoke out the exhaust. I have replaced the computer, the fuel pump, and the crank sensor. I swapped the map, o2, and ignition from known good running vehicles, nothing made a difference. The TPS is reading the correct voltage and the fuel pressure is 40 psi at idle. The only sensor I haven't replaced is the cam sensor.

 

Does anyone have any ideas? Thanks

[DiscoStudd]

Have you checked the IAC motor? That may have something to do with the engine dying when you crack the throttle. Could also be a vacuum leak somewhere. Have you checked the vacuum hose that runs from the brake booster to the intake manifold? How about the small plastic hose that goes from the intake snorkel to the rear valve cover?

 

Sounds as if the problem shows itself after the car goes into "closed loop," though. After replacing all of those items, and since you say it runs rich, I'm wondering if the injectors are leaking .

 

Just my $.02

[hotrod406]

I checked for vacuum leaks by spraying brake clean on gaskets and hoses and didn't find any leaks. Unplugging the IAC doesn't make a difference and it looked fine when I took it apart.

 

I don't think it is leaky injectors because it happened all at once. It was fine one day and doing this the next.

 

I also took the EGR apart and cleaned it out.

 

It's got to have something to do with how rich it is running.

[GP1138]

Maybe your engine backfired and killed your O2S.

[1990lumina]

any ses codes??

[topless94style]

Im almost thinkin its gotta be something with the injectors too.

[hotrod406]

I just double checked the IAC by swapping the one out from a known working vehicle and that didn't help.

 

The check engine light has not come on once during this whole thing.

 

I really don't think the injectors are leaking because of how suddenly this started. It was fine one day and doing this the next.

 

Could the can sensor have anything to do with it? I've got my doubts, but could it be telling the computer that the motor is spinning faster than it really is? The tach is reading correctly.

 

How can I check for codes without a scanner?

[DiscoStudd]

On a 95 with the 3100, you absolutely have to use a scanner to check for trouble codes (the "paperclip" trick doesn't apply.)

 

The cam sensor would be a good place to start since that's what controls the "sequence" that the injectors are fired. I don't know if that'll solve the problem though because IIRC, all that happens when the cam sensor is bad is that the PCM reverts back to "batch fire" (where the injectors on one bank are fired at once, instead of individually, just like the older "MPFI" engines.)

 

One other thought just sprung to mind: Have you checked the fuel pressure regulator?

[hotrod406]

I unplugged the cam sensor and it made no difference. I don't think that is it, it is just the last thing I haven't replaced.

 

Fuel pressure is 40 psi at the rail, so the regulator should be good.

 

I don't have a scanner, but my mechanic/buddy does. I guess I'll have to bring the car down there and have him look at it. I'm out of ideas.

[Canada]

You are going to have to check for DTCs.....this is assuming that the SES light is on.

 

Otherwise, you need to look at the data list on the scan tool and go form there.

[3pt1lumina]

My $.02 for whatever it's worth seems to think it's something to do with the injectors. How is the pulse coming from each injector?

 

This is random but maybe it will help. My friends 93 Regal 3.1 did the same thing you are describing and he replaced the plugs/wires/coil pack/ PCV valve all at the same time. After this service, car was and has been fine ever since.

 

Hope I helped and didnt confuse you more. :|

[hotrod406]

I'm bringing it in tommorrow nite. I'll let you guys know what it was when I get it back.

[hotrod406]

I finally got my car back. The first guy didn't even look at it for a month and it got broken into. Another month later and I took it to the dealership. They replaced the cam sensor and the MAP sensor. I am not sure that the MAP was bad, because I tried a known good one myself.

 

It runs good, but now I have to fix the trunk and the right rear quarter window.

 

Anyone have a window for me? I also need the plastic that goes on the back of the trunk.

[Psych0matt]

you should be able to find that at almost any junkyard, but im sure some guys on here might have those

[hotrod406]

Junkyards don't let people in anymore and they don't like separating windows from doors or trim from body parts. I need some door trim and can't get it anywhere because they won't take it off a good door. Hopefully someone has some of this stuff to sell me.

[Regalblue]

Well, I have this-> http://www.cardomain.com/ride/2067474