I have a 95 camaro rs with the 3.4L. starts fine everytime but has a rough idle. the motor racks violently during idle to the point where the hood can be seen moving. upon acceleration the temp gage shoots up to around 235 and stays until i get back into lower gears. The oil pressure gauge takes wild swings until i accelerate. the acceleration itself is also very poor. it will accelerate fine if i give it small amounts of gas but if i go WOT it bogs down and sputters to a point where it feel like its dying.
changed the plugs and cables
changed the egr valve
changed the thermostat
changed the water pump
fixed a small vaccum leak
changed the radiator
changed the throttle positioning sensor
changed the o2 sensors
replaced 2 leaking freeze plugs
and i still have no answer as to why it has such a loss of power and is overheating. i was thinking maybe the timing chain but i dont know if this would cause overheating too, any thoughts?

 

do a fuel pressure test, new fuel filter? i would do a compression test on your cylinders, are you losing coolant? are the radiator fans coming on? have you had it scannedd for trouble codes? how did the old plugs look when you changed?

 

What craby said but also test your coolant temp sensor. When those things go wrong your car runs like garbage because it doesn't know whether the engine is actually warm or if it's still cold.

 

I did change the fuel filter and tested the pressure and its all well within range, replaced the filter anyway. i'm not losing coolant anymore. after i replaced the freeze plugs the leaks stopped. the fan wasnt coming on so i replaced it with a dual fan and i had it scanned for codes yesterday after i replaced the tps and nothing changed. there were no codes at all. my old plugs were kinda gummed up but they were still the original factory plugs put in when the car was built, previous owner just kept regapping them i guess. i never thought to check the coolant sensor

 

have the injectors cleaned and flow tested. not exspensive and doesnt take long. should be a injector shop not to far away. i sent mine out ups and got them back three days later. used a place called doctorinjector. cost like 30 bucks for 8. it would also be a good idea to check the injector seals.

 

i've aready checked and treated my injectors and saw no problems with them. i think i may need to fix the timing chain and gears and see what happens from there

 

i would suggest you pick up a aldl setup so you can see whats goin on using your pc, got mine from moatts.

 

ok, i just finished a 8 hour run to pull apart the engine and replace the timing chain and gears. they were very worn, almost 2 inches of sloppy chain. so i put everything together excitedly thinking i had finally foundthe solution and i would have it running perfectly again, i was wrong. its all the same except that i have a little more pick up in the acceleration but still bad by far. now i'm going to move on to the fuel system as im starting to think that the fuel has to be part of it. any idea how to check fuel pressure and injectors on a 3.4

 

test the coils. could be weak spark. do a compression test, could have leaky or stuck valave

 

original plug wires?