95 3.4L big accelleration problem...

[MustangEater8251]

I am copy/pasting this post form another board.

a 95 3.4L camaro, with about 90,000 miles on it I think.
A problem started suddenly about 2 weeks ago that is really weird and I can't figure out.

When he accelerates, the car will run perfectly normal and accelerate perfectly fine up to about 3900 rpm and then it just STOPS. It will still just barely accelerate even under full throttle but the rpms climb maybe 50rpm a second at most and it wont really go above 4700. Any ideas what this could be? We've already changed out the plugs/wires, and checked for air leaks.

I'm starting to wonder if there could be an internal engine problem that could cause this. If anyone has any ideas I would really appreciate it, thanks.

[MustangEater8251]

I posted this about it.

.4L guys still looking into this thing about the computers. seems there are a bunch of OBDI with OBDII connectors, so makes it hard to get scanned anywhwere.
are you getting a SES code?

About the clogged CAT, how is your CAT on. I can take mine off and on with a little work because it is bascially on with bolts. I am not sure if stock cars have that.(On a side note open exhaust with little restriction gave me my best itmes on a 3.4L)

For some reason i think fuel may be the problem. any way you can check the fuel pressure?

When was the last time he did a fuel filter, maybe jsut thoro one on just ot have a good fuel filter on there.

Maybe check the coils. Use an ohmometer to check the secondary resistance for each coil pack, should be between 5,000-7,000 ohms, then check the primary resistance which is 0.35-1.50 ohms.

Loike said before by chuck all the senosro MAP, and such.

A semi problem with 3.4ls is they have a digital EGR valve system. It has 3 orififaces that send 7 different combination of gasses back itno the intake. Its controled by the PCM, but a problem with this system is Carbon build up is know to happen and cause it to freeze up and not work right. It will give a code 75, 76, or 77 if you are scanning your car.

EGRs are expensive to replace ~$300 I think.

I'll post your problem on another v6 board and get soem other opinions.

[zlightning]

what about tps sensor.

[Gmoney]

might wana check the clutch and such whether its a manual or not i had problems under 3000rpms but after that i was ok?? mayeb its jsut reversed for you?

[MustangEater8251]

the guy is saying he is not getting power above 3700, its a car guy I think he knows its something engine related, that the tdrivetrain is ok.

I was jsut thinking of the TPS.

Any more ideas?

[viper98885]

If he gets good acceleration at WOT through 4K RPM's or whatnot, it would not be the TPS. If it was the TPS, then somewhere in the 0% throttle to the 100% throttle, there would be a complete jolt or loss of power.

[Tiago]

could be totally dead valve springs??? Valve float...

[Fin]

I recall someone elsewhere on another board I frequent having a similar problem w/his LT1 Z28. However, he had installed a MSD ignition (which he removed, but did not fix the problem). I would definitely have the entire ignition system checked out, as well as MAP, TPS, EGR, etc. all checked out before assuming the worst (by the way you can pick up an EGR from places like Autozone for around $160). From the description of the problem, I would believe the problem isn't internally-related, but rather electrical in some way.

[Tiago]

I would guess ignition before anything else

[EyeOutThere]

I had a problum like this with my 1994 3.4L V6. It would accelerate up to about 4000rpm then it would lean-out and sputter.

The problem:
The wires going to the EGR valve were close to some exhaust parts and started to char crack. Cutting out the old wires and soldering in new ones fixed the problum.