onebad400

Has fuel...has spark plug wires are correct... But spark looked a little weak, how do I test the ICM and is that where I should start... Pulled #1 plug after trying to start and it was wet.... Also has new fuel pump, wires and plugs....#7 injector was only reading 9.2 ohms so I know I need to replace it as well but where should I look next

T/A

does it start if you spray starter fluid into the plenum?

onebad400

Sprayed starter fluid in it and now it starts on its own but acts like it has a miss scanned the computer and no bad sensors

T/A

the miss is probly causing it, had the exact same problem with my 90 trans am.

onebad400

What was causing the miss? It has to be mechanical I am doing a compression test this weekend

T/A

you said injector seven was reading 9.2? thats probaly whats causing the miss, the injector isn't working.

onebad400

I replaced it already and it is stil missing. could a injector read the correct ohlms and still not fire... and would that throw a code hooked up a live data reader and all the sensors were working and the injector pulse was ok.

T/A

are they all reading 15 ?

as for the code only one way to find out.

onebad400

There are no codes, and they all read 16.2 or with in a ten hundredth

T/A

interesting, i need to research a little,
but i'd say its, something with injectors considering that it won't start except with starter fluid.

onebad400

After you.get it started once it starts its self

redneckjoe

cold start system working?

onebad400

What's the cold start system? Would one injector not firing cause a code

TTOP350

iTrader: (8)

last year 4 cold start was 87. He has a 92.

onebad400

91 but same difference

ASE doc

It's quite possible that your hard start and misfire are related. The misfire is certainly where I would go first, just because it's much easier to pinpoint. No, your 91 will not set a misfire code. Misfire codes(P0300-308) did not start until 1995 with OBDII. Many things can cause a misfire or a rough idle. Connect a vacuum gauge and watch for a jumpy needle for a clue to a bad intake valve. Use a KV tester to measure KV from the ignition coil, then at each plug wire to look for a leaky wire. Use a scan tool to monitor BLM and Integrator to look for a lean or rich condition. Use a smoke machine or carb cleaner to look for vacuum leaks.

To find a misfire, start with a power balance test. To do this you will need to disconnect the IAC with the car running. Yes this will set a code but we don't care about that right now. Then, using spark plug boot pliers with a ground lead attached so that the pliers become a ground, pull one plug wire at a time from the cap. As you remove the wire hold the pliers close to the contact of the cap to so that the pliers conduct the spark. Note the rpm drop as you remove each wire and look for one that drops less than the others. Once you find the cylinder that doesn't drop like the rest, you have found your missing cylinder. Now you can focus on that cylinder with a compression test and leakage test to determine the cause of the miss. The leakage test is vital because even if the cylinder passes the compression test, it may have a leaky valve that is causing a power loss. Once you verify mechanical health, you can swap injectors with another cylinder to see if the misfire moves with the injector. You can also swap plugs from one cylinder to another to find a bad plug.

onebad400

do 91 trans am have/need a mass air flow sensor. also does anyone have a picture of one and the plug that hooks up to it?