missing 3.4

[birdman]

i seem to have a miss all through the rpm range and sometimes when i start it it feels like its running on 4 cyl. and if i give it gas and rev it up a couple good times it will run on 5 cyl. on 5 it seems to run pretty good but if your in park and hold the rpms at like 1500-2000 you can feel a very constant miss so i know its the same cylinder. any ideas on what it might be?

[pepsi_coke]

Could be:
-Spark Plug
-Spark Plug Wire
-DIS/ (ICM/Coil pack)
-Faulty fuel injector

Can you throw us some more info? Does the cat converter glow after drives?

[birdman]

i got new plugs and wires but he plugs are autolite and i heard your supposed to use ac delco or bosch??? and my wires are only 7mm so i dont know if that could be a problem. the cat dosnt glow and as for the injectors and icm, i dont know what condition their in. how could i check??

[pepsi_coke]

Autolites should be fine. Bosch sucks, leave the German parts for the German cars. AC Delco is always the best way to go for obviuous reasons.

7mm wires are just fine. In ignition, as well as many other things, your only strongest as your weakest link ..

Did you re-gap the plugs?

[birdman]

they were pre gapped but i did check them and they seemed ok.

[Synestral]

If you've got a cylinder that doesn't fire, and it's not the ignition system, it's probably the fuel system. Do you know for sure that you are getting spark to all the plugs? If you are, you might have an injector that's not firing for some reason: clogged, not getting signal from ecu.

[birdman]

im about to get a timing light and check all the wires. if they all work how could i check the injectors? can i just listen for the ticking?

[Synestral]

I don't know any do-it-yourself ways to run an injector test. Only way I've done it is with a diagnostic scan tool and a pressure guage.

[birdman]

i put the timing light on it and cyl. 5&6 were missing pretty bad at an idle and reved up and the rest were fine at an idle but had a sparatic miss when reved up. i just removed the coils and the icm, is there any way to check if there ok?? if not im going to clean the terminals because everything was real grimey and see if that helps.

[Kohburn]

have you done a compression test on 5 and 6?

[pepsi_coke]

Hmm! You do know that cylinders 5 and 6 are on SEPERATE coils, rite?

If it was coils and 5&6 are not firing rite, this means that Cylinders 5&2 (same coil) and 6&3 (same coil) would also be missing IF the coil packs were shot ..

Just some food for thought ..

-Jay

[manny]

Here is a link for how to test your coils:

http://members.fortunecity.com/slade901/automobile/Ignition_Troubleshooting.htm

You can do an ohms test on your injectors. They should be relatively close in tolerances (my 3.4 injetors measured between 12.0 & 12.2.

I also got an addtional injector plug from the j/y and I lengthened the wires to use as a tester (just to verify that each injector was actually working.)

[birdman]

i just put on coils and icm off of a 95 lumi and it now misses on only one cyl and seems to be about half the speed on that wire. could it be the crank position sensor? any ideas?

[birdman]

this is driving me crazy. anyone please help. today i was messing around with the coils, i put one of the old coils on the cyl number that was missing and it made no difference. do yall think i just got another bad icm because i can go back and get another one to try for free. what other parts of the ignition system could cause this?? like i said all help is welcome even if its just an idea, please help its driving me crazy. thanks.

[birdman]

today i put my third set of icm and coils on and it made no difference, i cant think of anything else that would cause only cyl 3 to miss. are there any sensors that would affect that or any other electrical systems that could cause that?