Have replaced injectors ,temp sensor,coil packs,spark plugs and wires what could be the problem?
Leaking intake manifold. Confirm with vacuum guage.
SOURCE: 1989 BMW 735i Hot start issue
You might want to try replacing your throttle return spring, or at least lift the hood and see if here is a change while it smooths out..
SOURCE: car wont start
I noticed you replace the crankshaft sensor, but not the CAMshaft sensor.
The Ignition module takes the input of both sensors to tell the coil when to energize.
This sensor should come up as an error code when you attach a obd reader.
Even if your light is not on - there may be a code. If it is not your vehicle originally, some people pull the bulb!
SOURCE: INTERMITTENT SPARK
Make sure the spark plugs are not platinum or anything other than regular copper plugs. The S-series uses a "waste spark" system and will destroy platinum plugs. Regular copper NGKs that came from the factory with the car work the best.
How do you know it is a spark problem? Are you able to verify spark, fuel and compression?
I ask because the usual solution to what you are describing in your problem is replacing the Engine Coolant Temperature Sensor (ECTS). The factory one is plastic and cracks. When it cracks it sends the PCM
a signal that the engine is 40F below zero. The PCM will compensate by
dumping A LOT of fuel into the engine to try and warm it up. It will
cause all kinds of starting and idling problems.
Autozone or the
dealer sells the better brass tipped one. The ECTS is located just
under and behind the upper radiator hose. You'll need to remove the air
intake tubing to see it or get to it. It has two wires going to it and
goes into a connector. Squeeze the connector at the "ears" and it will
come off.
Now is the time to check the connector for corrosion and gunk. If there is clean it out very well. If there is no gunk or corrosion continue on.
A 10MM DEEP well socket will take it out. Swap it quickly
because some coolant will come out (a couple of ounces). Hand tighten
it and snug it with the socket (not too much because it will strip
out). Connector back on (either direction it's non polar). Put the
intake back on and enjoy better starting and idling.
SOURCE: no gas, no spark, 1991 chevy cavalier 2.2l 4cyl
This is an all too common problem with the Cavalier and other GM J-body cars. Usually it is because of the crankshaft position sensor or the harness going between it and the DIS (aka ignition module). Without the DIS seeing a signal from the crank sensor, it doesn't know when to trigger fuel and spark.
Sometimes this can also be caused by a faulty ignition switch. The switch will allow you to "crank" the car, but it doesn't make the proper connections for the ignition system, so the car never actually runs.
The previously indicated oil pressure switch could also be causing the problem, but if you hear your fuel pump run then it's OK.
Hopefully this helps. If not, your Cavalier is as messed up as mine and probably not worth fixing.
SOURCE: 1991 Olds Cutlass Ciera 3.3 v6 would start, run a
jrtvett's "unplug one injector and start" troubleshooting procedure would work if one injector is bad. If more than one injector is bad, then not so sure.
Like you mentioned, one or more injector(s) can go bad and it causes the others to stop working as well. After our experience, I am convinced this observation (fault mode) is correct (see below). Its as if upon warmup the solenoid in the faulty injector shorts, resulting in short circuit of signals to all the other injectors.
We have a 1989 Olds Cutlass Ciera with the 2.8L V6 that recently had the same fault: At least one injector went bad after warmup, then engine refused to restart. All other possibilities were eliminated, including crank shaft sensor, ECM, ignition pack, idle start valve, bad gas, rail pressure, etc.
No Service Engine light illuminated, and there were no fault codes in the ECM computer.
The jrtvett procedure could not easily be utilized in our case because all the injector connectors are underneath the intake manifold and inaccessible.
My cousin is a Ford mechanic told me of an analysis procedure Ford uses to troubleshoot injector problems. They display rail pressure on a LCD or CRT monitor and can see pressure drop with each injector's opening. Unfortunately, if the car is not starting, then this test will not be of much use. The engine has to be idling or at least all of the solenoids in all of the injectors operational to use this test. If engine won't start, then its clear none of the injectors are opening as described above, then no fluctuations in rail pressure would be displayed.
The shop that was working on our car decided to replaced all of the injectors, and the engine now runs like new.
Due to inaccessibility of injectors and fact these injectors were inexpensive ($40-$50 each), it was wise just to replace all six. Grading old injectors is not exact science.
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