Engine missfire/stalling problem

Ok I've just done a engine replacement into my cavalier. I am getting a missfire above about 4000rpm (really suddenly and very consistantly). Also when you rev the engine a bit and then release the accelerator the rpms drop way down and the car nearly stalls (the harder you push the gas initially the lower the rpms drop after releasing). The exhuast is also rather smokey, sort of a grey color.

Could this be because the first sensor (in the exhuast manifold) is unplugged?

96 Cavalier
Z24
4 speed auto

Thanks

Wes

did you use the intake and sensors from the old engine? scan for codes, this will tell you which cylinder is missfiring or tell you if it's random. why is your O2 sensor unplugged??? it's a pretty important part of the engine management system. also replace the fuel filter it can cause this problem. by unplugging the O2 sensor the computer can't go into closed loop which is important for economy and performance. where did you get this engine?? most auto recyclers pour oil in the cylinders and it takes a while to burn off. i assume you put new plugs in. have a look at them every spark plug tells a story. does it missfire when you drive it or when reving in park?? if your in park it's just the rev limiter cutting in. good luck i hope you getter fixed up!!

Hey Amac, thanks heaps for the post! :)

The sensors and intakes etc are all from the new engine (so i actually have some spares to play with). I think you're right about the rev limiter, because its almost like hitting a brick wall rather than a missfire (and it was in park! hehe).

I had the vehicle into an auto electrician because it wasn't getting a spark (turned out to be a burnt out relay). He scanned the ecu and didn't mention any missfire codes, so i guess that is all ok. However the oxy sensor in the manifold was damaged so he disconnected it. I have a spare but it is a sod of a thing to get to to change it! I think that may be the reason why it nearly stalls when coming off revs (i hope!).

Yes and you're right again, the engine came from a wrecker so I'm hoping they have just oiled the cylinder.

I hasn't stopped pissing down with rain for the last few days so I hope I can get out soon and have a play! :)

Thanks for the tips! I'm actually in New Zealand so its a little hard to find people who know about these cars!
I'll let you know how I get on

the O2 sensors not that bad to change on that motor try using a 7/8" wrench that always works for me. take a good look at your throttle body expecially the butterfly(throttle) valve. if this motor was in a rollover there might be oil deposits on the engine side of the valve. clean it with some carb cleaner and rags. maybe swap the iac(idle air control) motor with the one from the old motor if it's full of crap it will idle like crap. good luck . let me know if you have any further issues.

Ok, heres a little more news.. looking quite bad. I put her in neutral and slowly reved upwards to see if it was the rev limiter. As I get up to 4000RPM once again its like hitting a brick wall and then I notice huge amounts of white exhaust coming out the exhaust pipe! I turn the engine off and check the engine bay. Oil has overflowed out the dipstick!

It is looking to me like there might be a compression problem here would you agree?

Wes

Just a though, could it be that I have overfilled the oil? How much does the cavie usually take?

check the coolant level. these are the symptoms of a blown head gasket. look for milky(coolant) stuff in the oil, oil in the coolant, low coolant. thats definetly the rev limiter you're hitting and a 2.2 cavie should hold around 4L of oil. if you want to confirm the head gasket you can do a compression test, cooling system pressure test, cylinder leak down test but white smoke's usually a sign.

Ok, some great news!

Turns out the engine was overfilled with oil - my bad and we'll leave it at that! hehehe

Ok so now there's no cloads of smoke coming out and it all looks like its working properly! Happy days.

After taking it for a quick spin I broke the 4000 RPM mark too sweet as! :) :) :)

I am concerned about the transmission tho. When i put it into drive it gives an almighty jolt. Same thing with reverse but not quite so bad. Could a high idle speed be causing this? Also under a bit of load there is a tinny vibration sound.. could just be something rattling or may be exhaust related. Also the timing chain is quite audable. Not overly load but certainly noticeable.. is this normal?

P.S Thanks so much for helpin me with all my stoopid problems! :)

most of the timing chains make noise on the 2.2L did you check the tranny oil level? check it after driving several miles(at least 5). check it with the engine idling in park on flat ground. tranny uses dextron III.i usually change the tranny oil/filter every 40,000km more frequent than gm recomends but good p.m. to rattle is probably a loose heat sheild somewhere on the exhaust. jack it up and smack the exhaust with a rubber hammer you'll find the rattle in no time. the timing chain is a pain to replace but if it breaks you're gonna need a new engine.

Hehehe I like the rubber hammer trick.. I'll do that. :)

Now I had a bad experience before when trying to adjust the transmission oil level. As I understand the cavies have no tranny oil level indicator, only a level adjustment bolt right? As I understood it you needed to have the engine going and have the bolt removed while adding fluid. Only when I did this the tranny promptly pumped all the fluid out the hole! Can you shed some light on this? I'd say I have about 8l in there which is about how much I took out when I drained it.

I'm not to worried about the timing chain, its just that i'm used to cars with timing belts.

i guess you have the 4sp tranny. it has a red filler plug under the air intake hose huh?? i didn't think they used that one in 96 but i guess it's possible. whenever i do a fluid/filter change on that tranny it takes exactly 6L. the fluid should be level to the bottom of that side plug. i'd say you need to drain some out. if you leave it overfilled it could blow out seals and not shift right.