Alright first off I have a 1996 Camaro RS 3.8
86,9XX miles motor and trans
Ever since I bought it, it has stuttered, bogged out, lacks power, hesitates, and stalls out..


I have replaced the following.
TPS
MAP
MAF
02 sensors
Cleaned the TB
Cold air intake
New injectors
fuel pump
fuel filter
fuel strainer
ECM
MAF pigtail

I was told when I bought the car the guy took it to the shop and charged in $900 to replace coils, plugs and wires (shops are outa their mind huh?)
And after he got it back from them its just gotten worse
And apparently they messed with the timing aswell.. So idk what they did. Im gunna borrow a timing light tomorrow and see where its at, and see where it should be.

Im not getting any codes. But if I pull the fuse for the ECM and let the car sit over night it will run fine for about 5min and start all over again. So im not sure on this one.

Kinda losing my mind and its annoying the F**k out of me.

so any suggestions would be a great help (besides taking it to a shop I do my work myself)

Right now im thinking plugs are bad, or not gapped correctly. Gunna pull a couple random ones tonight after she cools off and see what they look like and where they are gapped.

Timing possibly

And then theres the possibility of the CAT being clogged

 

The timing is not adjustable and is controlled by the PCM in response to inputs from various sensors. Before throwing more parts at the engine, pull all the plugs and take a good look at them, they will give you a good idea of what is going on. Also, scan the engine and see if there are any codes, if there are, take care of them first. Also test the TPS, and the ignition control module. Check the ignition wires, and make sure that they are routed properly, just because some one changed them does not mean that they are good. As for the cat, the usual symtom of a clogged cat, is that the car starts OK and seems to run OK at low RPM, but will poop out under load at high RPM because it is getting choked on its own exhaust. It will caome back to life if the RPM and load drops when there is less exhaust produced. There are exhaust pressure gages that plug in place of the O2 sensor, or you can unbolt the cat and see how the engine runs in that condition. It will be very noisy and be careful not to start a fire under the car. Also, make sure the EGR is working properly.

I am not trying to be sarcastic, but next time do not buy a car that runs poorly, unless you know exactly what is causing the problem. LOL

 

Timing is not adjustable on a DIS (direct ignition system)

Drivability 101, Your complaint and no codes.

Test your fuel pressure.

Test exhaust back pressure.

Test engine vacuum. The engine vacuum can tell a lot about what is going on in the engine. I can not expain everything, but at this point you are looking for the needle to be smooth. If it is not you MIGHT be looking are a mechanic engine issue.

Last thing I would do under the hood is remove the EGR test it for a good seal and check and or replace the PCV valve.

After all that was done I would get into the car with a scanner and start reviewing all the sensor data. You could have a bad connection at any sensor s your have already replaced.

Edit: Opps I type all this before Pete's post was there. I had to feed the baby and forgot to hit post

I will add you can install a Vacuum/Pressure gage where the O2 sensor bolts to the exhaust disable the ignition system and crank the car over. you should have less then 3 lbs of pressure.

 

Mine was doing that and I replaced the plugs, coil packs, egr valve and it had no effect on it. I replaced the cam position sensor and it corrected the problems I was having. Mine was so bad it would not even pull itself.

 

That should show up in the engine vacuum test as an erratic vacuum. Does anyone know if the CAM sensor can be checked with a dewell meter? I assume is a signal like a pickup or hall effect switch outputs.

 

seems the op has replaced everything except the cam sensor.

 

Cam sensor sounds like. Although it could be a possibility that it's a clogged cat like Pete said.

 

He needs to stop throwing parts at it and figure out whats going on. From his list of part he has replaced I see EGR valve, PVC valve, fuel pressure regulator and Cat are missing. With a no codes lack of power issue they would be the first things I would check. The fuel pressure regulator would most likely show as a code. But the other three things I would have checked even before I replaced all the wires and coils. Although the car most likely needed those things thats why they where done first.

It very well may be a Cam sensor, it could be any part of the primary side of the ignition that would cause erractic spark. I would put this as an uncommon issue. Most of the parts he has replaced have easy tests with simple pass fail indicators.

 

Alright Pulled a couple of the plugs already..
Come to find out that the ones I pulled so far are good..

Remember how I said the previous owner took it to the shop and they charged him $900 to replace the caps, wires, and plugs? Well they did that..

But they did NOT Gap them.. They looked like they were taken out of a box and thrown in there.. Gapped a few of em already test drove the car and guess what??
NO STUTTERING.. NO BOG OUT.. NO STALLING.. NOTING!!

Time to do the passanger side... this should be fun..

$3000 later and come to find out that it was the plugs not being gapped... God im stupid..

 

So here is a list of things I did to the car..
Everything is after market because I thought well if its broke might aswell blow the savings..
New injectors
New Cam
Heads were redone
Cold air intake
PCM with tune
Fuel pump
Water pump
Tensioner pully assembly
New radiator
New water neck
New hoses
New filters
PCM with tune
Rear end from a 97 Z28
1 Piece aluminum drive shaft
Drilled and slotted rotors

What needs to be done now..
Tires for the C6 rims
Paint
Install headers and buy exhaust
Rewire the door controls

And right now im looking at a NOS set-up
Estimated time on the LAS VEGAS Drag Strip. low 14's