Cavalier 99 2.4 engine 110,000 miles
Got rough idle at 650 rpm and my mpgs around 280 miles a tank mostly highway miles
Its kind of an intermittent miss fire its not too bad but it aggravate me idle is steady but I can feel the car shaking a little bit
Just replaced :
Spark plugs EM AC deco...old ones where worn out
NO sings of oil or water on old plugs ,seemed clean no residue
Fuel tanks pressure sensor... got cell code P0453
intake manifold gasket... (was leaking)
Injectors o rings upper and lower...(was leaking from lower,but replaced all just in case)
Inspected fuel injectors turning the on outside seemed working properly NO dripping
Cleaned fuel system with SEA FOAM twice and another bottle on the intake side(vacuum line)
Fuel filter...was very dirty inside
Air filter
Fuel cap
Cleaned throttle body
Cleaned Idle Air Control Valve and passage
cleaned intake manifold ,inspected for cracks or leaks seems ok
Cleaned intake ports on cilinder head
Inspected again for vacuum leaks seems OK
Tested with Carb and choke cleaner no a parent vacuum leaks anymore
No fuel smell on exhaust pipe, no smoke.
No more CEL but still got the rough idle and the low mpgs
I'm assuming this cars get 26-30 mpgs
Fresh oil and filter semi synt rotella shell
Fresh oil and filter transmission
Any help would be appreciated, thanks
Car doesn't hesitate or misses at load
Compression test was done today...
208
209
209
210
with engine at operating temp.
Plugs look clean ...
The numbers looks kind of high to me but I guess is the gauge
Thinking about fuel pressure regulator,camshaft sensor and coils
Don't want to be dumping parts in just because...
I have no CEL on
today I noticed that when I Reved the engine in neutral it does a little shaking at 2,5k rpm and kind of goes up and down a little bit
Any help would be great,thanks and sorry for the long posts
Replaced crank sensor was craked on top and soaked in grim and oil ...still nothing
I would check the resistance on your coil packs. And get your ignition control module tested. If that all passes, then check your fuel pressure and etc...
I quoted myself from another thread, lol.
Freelancer1988 wrote:Check the resistance Your coil is the c852. HERE is a link. Also take your ICM to advance or autozone and they can hook it to a wells tester. If you also have no way of testing it, then ask to use a ohmmeter as well. I recently had a similar problem and it was one of my coil packs. I had no power when trying to accelerate and it was intermittent. I had no resistance at the secondary check.
Got the multimeter, checking those coils tomorrow.
Replaced upper o2 sensor and still rough idle...
Shaking comes from 2,200 rpm trough 2,500 rpm then its fine
Tested coils and ICM they are with in specs...
Inspected fuel pressure regulator, its OK
Map sensor is on specs,
Put another sea foam on gas tank ...
Any ideas?
Need help please ...
The last thing is my gas pressure
Replaced cam sensor ,still nothing
Replace the coil mounting bracket, aka the distributor cap.
Just ordered it yesterday ,I hope that would solve the problem...
Gas prices are starting to go up again
I am experiencing similar issues. OP did the coil mounting bracket fix your problem? Whatever happened to this?
