Hello...I am new here (obviously). My step son has a 1988 Camaro with the 2.8V6. It is really hard to start and dies when put into gear. Refuses to idle at a constant speed when we do get it started. Here is a list of what we have tried:

New fuel pump/filter
new ecm temperature sensor (was throwing a code)
rebuilt throttle body with new throttle position sensor and IAC
Fuel pressure test - nice steady 40PSI
New cap, rotor, coil,wires,plugs
many cracked/broken vacuum lines replaced
New plug on the alternator - wasn't charging correctly (14.5 volts now)

I managed to get it to idle at 850 long enough to get the TPS set according to the book. This problem occurred rather suddenly so I am not even sure what to do next. I hate to throw another 300-400 bucks for a ecm and more new sensors if I'm not really sure that's the problem.

Any help would be appreciated.

 

unplug the CTS and see if it runs marginally better. Any difference in how it runs after it has sat and cooled off over night vs. when it is warmed up?

 

The egr valve might be sticking open at idle (which it shouldn't be) causing the stalling, hard starting & rough idle. Unhook the vacuum line to the egr & plug it, drive the car for a couple of days to see if it acts up.

 

WOW thanks for the quick responses. Did some more testing, pulled all the plugs, they were soaked in fuel. The wires were okay except one which the end had come off. I tested the compression and got this:

1 - 90 Lbs
2 - 80 Lbs
3 - 100 Lbs
4 - 50 Lbs
5 - 70 Lbs
6 - 50 Lbs

very bad readings but wouldn't keep it from starting. Did a static timing test to see if the timing had jumped...it hasn't. I'll try the egr and cts thing during the week.

 

Sometimes when the engine is running rich, the oil on the cylinder walls get washed off causing low compression readings.

 

Check the injectors, may be leaking. Could also check the 02 sensor, easy enough to check

 

not an expert on this but shouldnt the fuel pressure regulator also be suspect

 

I'll one up this, if the plugs were soaked in fuel, lack of fire to the plugs, or not enough to burn up all of the fuel, you may have washed the cylinder walls. I'd replace the plugs and wires, and then work your way from there. Also possibly the EGR like was mentioned before.

 

Not a master of the V6 engines, but I would start with the timing, make sure its at a reasonable degree and all plugs are firing. Move on to fuel, check the regulator..pretty sure you pull the vacuum line and if its got fuel in it its no good. Check the injectors to make sure they are all firing properly. My old Fbird had the 3.1 and it had 2 shorted injectors that caused similar issues. After that Id check the air passages including the filter, and make sure the vacuum lines are going to the right places and functioning properly.

 

I think there is a bit more wrong here than fuel washing the oil off of the pistons/cylenders , and here's my reasoning ;

Were the low numbers the result of "washing" i'd expect universally low numbers throughout the engine . You've got one cyl at 100 pounds and one with 50 pounds , that variation is far too great to be explained away by washing . If ALL of your cyls were low in the 70 to 90 realm , yea , could be washing , but to have a cyl at half the compression of any others points to a larger failure .

Leaky valves , worn pistons/rings , or some lobes worn almost clean off of the cam would be a few of my guesses of things to check .

Remember , most repair manuals call for no greater than 10% difference between cyls , and you've got one Hell of a lot more than 10% difference between 50 and 100 psi !

Best of luck with it ....

 

I agree with Init4fun. Looking at your compression pressures there is to large of a difference between them. Do you hear any odd noises when you try to start it? Things like a wiped lobe or a bent valve will make noise. You could also do a leak down test. Sounds like you got a serious problem for sure.

 

I agree- that poor beast is hurt. my neighbor has a good v-6 that we pulled out of his 86 that he'd sell fairly reasonably..it did run good when last tried. Let me know if interested and i'll get you his phone number.

 

Thanks guys for the backup on my thoughts , In this case I almost hate being correct , cause it means the OP is in for some engine work ...

Also !

Upon second and third thoughts here .... The OP said he had only 50 pounds of compression in both cylender # 4 AND cyl #6 . Now , our beloved lil six has all the odd cyls on one side and all the evens on the other . Wheras #4 and #6 are right next to each other , and both showing **** poor compression , I'd be STRONGLY considering pullin the head and likely finding a big ol chunk blown out of the headgasket between those two cyls

 

Just do a wet comp. test.

 

Well, we threw in a new computer and distributor. Started right up , ran for about 15 minutes....then went back to same problem. Radiator sprung a leak and we found oil in the water. Looks like init4fun's diagnosis of a blown head gasket is correct. Now my son has to decide on sinking $1500 for an engine or buying another car and selling this. Thanks for all the help

 

you might not have to buy a new engine. it could possibly be cheaper to have that one rebuilt. Do some research on some shops and figure out how much it will cost to have the cylinders bored and honed. freshen the heads and put it back together. also this would be a good time to internally balance the engine if it isn't already done. just cause the head gasket is blown doesn't mean the engine is trashed. this is where the fun begins.

 

Just an update. Stepsons' friend was parting out his car so we bought his engine for $200 bucks. Working on replacing the valve cover and top end gaskets. Should have it back in today or tomorrow.

 

good deal- you might think about the pan gasket and rear main seal while it's out. those parts are cheap but are a big deal if it leaks after it's in there! good luck!

 

Someone already did those things thank goodness. Engine is back in car and it runs!!! Had to go get a new alternator and battery and move the plug wires to get it retimed (new dist didn't want to line up where old one was) but it runs. It'll be on its first 90 mile trip tomorrow night

 

sounds good. good luck!

 

congrats on getting the car running. have fun on the big trip. I'm nearly done with my mods just gotta wait till tomorrow to get what i need

 

Car is running quite well. No check engine light or any of the past problems. Unfortunately one of the rear brake cylinders blew out so car is down again till step-son can get some cash to replace them.

 

Be a good stepdad and buy him his cylinders! I've got a softspot for kids with cars that "almost run"...that's why my son's cars are in great shape and the checkbook hurts!

 

I couldn't agree with you more. I've been fixing, repairing and replacing parts on my son's 87 GTA and it's coming out great. He's a full time college student and great kid to boot ! So long as he keeps up his grades and maintains his scholarship, I have no problem helping him out.... Beside, I get to drive the car once in a while !!