I just changed the head and intake manifold on a 94 2.2 auto Cavalier I plan to use for a daily someday.
The facts:
The car ran perfect before I tooled on it.
It had the typical external leaking head gasket problem.
I took the head from a good running 95 2.2 and had it cleaned and checked for cracks etc.
Ported/polished/gasket matched the head, then sent it back for a clean up cut and a valve job.
Took another MPFI lower intake and gasket matched/polished it.
Bolted the original 94 upper intake to the other lower I cleaned up.
Used the complete 95 head-including the whole EGR/T-stat housing... including the 95 EGR valve.
Re-used the original 94 injectors and FPR.
The good:
The car runs great at WOT.
The bad:
It pops when idling and has a slight hesitation.
It starts goofy. (Needs to be given throttle to start and not die)
When revved at WOT, it easily pulls to the rev limiter. It makes a really strange fluttering sound when revving down. Hard to explain, but to a trained ear it sounds really strange.
The diagnosis thus far:
All cylinders have good and even compression (140-145)
Vacuum is good. With the intake hose disconnected from the TB, the TB will violently pull my hand against it and kill the motor instantly.
No CELs.
Tomorrow I plan to put my scan tool on the car and look for something out of place.
Hopefully I just overlooked something simple... god knows I've done that enough!
It just baffles me that the car ran perfect before this.. Argh!
JLP
90 Cav<--- "1LE" MPFI car
79 Monte<--- 11.82 @ 112.72
Did you connect the purge valve vacuum lines correctly? I had a similar problem with mine.
IIRC, there were only two vacuum lines to reattach at the rear of the motor. One was a hose and went to a T fitting near the firewall, and the other was a plastic line that went to a plastic block right below the head on the middle of the engine block. The front two connections were FPR and EGR also IIRC. James, is that what you were referring to?
JLP
90 Cav<--- "1LE" MPFI car
79 Monte<--- 11.82 @ 112.72
Yup. There are two vacuum ports (well, one is for LMV, the other is the purge line from the fuel tank) on the EVAP purge solenoid (the plastic block). I had the hose hooked to the wrong one and it idled like crap. ALso check the vacuum manifold (the plastic thing that clips to the top of the IM where all the lines go). Sometimes the little rubber grommets slip or crap gets in the hole.
OK, had a chance to hook up my scan tool today. All systems are a go except for a bad #2 Quad Driver. Seems quite goofy an injector could crap out from just being swapped, but stranger things have happened I guess.
Does anyone know off hand what ohms the injectors should show? Am I correct in thinking any possible injector problem causing a bad quad driver should be electrical and show with an ohm test?
As odd as it seems that an injector would die like that, it seems even more far fetched that the ECM is suddenly messed up. Hmm
JLP
90 Cav<--- "1LE" MPFI car
79 Monte<--- 11.82 @ 112.72
I have 11.8 to 12.6 ohms.
Is the wiring to #2 undamaged?
Alont
Are you using the stock ecm? The quad driver is not the injector driver. The quad driver is used for things like EGR solenoid control (when equipped), TCC solenoid, A/C clutch control.
The housing for the EGR valve on the end of the head is slightly different between the 94 and the 95 engine. Either housing will work on either head, but you have to use the gasket which matches the housing or you'll end up with a vacuum leak.
Also be sure that your EGR valve isn't opening at idle. I certainly can't remember if those are positive back pressure type valves, but I know the 95+ exhaust system is different which could cause different pressures. You might be able to put your fingers around the inside of the valve and feel the diaphragm while the engine's running. If it's moving then you may have found your problem. Also make sure there's no vacuum at the EGR port at idle.
Stock injector resistance should be about 12 Ohms. A crude field test is to place the tip of a long screwdriver on the injector and place your ear to the handle to listen for the injector ticking while the engine is running. A shorted or open injector or injector driver will generally cause the injector to be silent or to operate very weakly. You can probably rule out the injector drivers for this simple reason: 1 driver controls 2 injectors and you'd have a helluva chitty idle if there were 2 injectors failing to open.
Using a vacuum gauge can help you decide whether or not your valves are adjusted properly. You should see fairly steady vacuum readings. A reading that jumps around can indicate a valve which isn't sealing or one which is too tight. A reading that drops suddenly and regularly can show a valve which is too loose. You shouldn't have a problem with valves out of adjustment but when you mix and match parts, anything is possible.
HTH
-->Slow
Yah, stock ECM slow.
Hmm, I havent had a chance to work on the car.. however I did leave out the fact that I ripped all the AC stuff off the car. That said, all my AC wiring is uncut and just tucked off to the side not hooked to anything obviously. I did the same thing on my 93 race car and it didnt affect anything... is the 94 ECM different?
JLP
90 Cav<--- "1LE" MPFI car
79 Monte<--- 11.82 @ 112.72
Had a little time to mess with the car today.
All vacuum lines are connected and accounted for. There is no vacuum at the EGR port during idle. Spark plugs are all evenly black and sooty. The car sounds so funny I thought maybe the exhaust got plugged up when it was apart (mice or who knows what.)... unhooked the downpipe from the manifold.. same thing.
When I first started the car today the brake and ABS lights were on. I cannot get the computer to go into Field service mode with my scan tool either. There is no SES light when the car is running bad, but if I randomly pull the plug on a sensor I get the SES light, and it stores correctly in the ECM.
I'm gonna grab a spare ECM to try, but if that doesnt solve it I'm gonna be pretty stumped.
JLP
90 Cav<--- "1LE" MPFI car
79 Monte<--- 11.82 @ 112.72
What kind of scan tool are you using? I've had issues with some of them not even recognizing the ECM.
James,
I bought the scan tool I have from Auto Zone a few years back. Not sure on the brand name off hand, but its been a pretty decent performer thus far.
JLP
90 Cav<--- "1LE" MPFI car
79 Monte<--- 11.82 @ 112.72
I'd say try the spare ECM.
For anyone curious, I solved the problem.
The head gasket sets for these motors (at least the ones I buy) come with 2 gaskets for the EGR housing.... and you guessed it. I had the wrong gasket in there and the EGR valve was partially open all the time. So kudos to those who guesses an EGR related problem, and thanks to all for the tips.
I've done this stuff enough where I shouldnt make mistakes like that. Oh well.
JLP
90 Cav<--- "1LE" MPFI car
79 Monte<--- 11.82 @ 112.72
