stalling issue at upper rpm's

[bbeck]

I've been having a slight missing issue that I can't eliminate. It seems to run smoothly when it's cold, but as soon as it warms it starts to miss. The only code it's kicked is the o2 sensor. I've replaced the o2 sensor and the crank sensor. And I've had to replace 2 coils recently. But besides the missing that is annoying me, it cuts out at higher rpm's once in a while- usually between 4-4.5k.. I thought it could be the ignition module giving me problems, so I took it off and it got tested numerous times in a row to heat it up with no success at failure. So, does anyone have any ideas? I'm just lost right now. I'm going to pick up a fuel pressure guage to check that out, as it is definitely running rich. Just this last summer, it was running fine and I was pulling 30+ mpg.

[bbeck]

can someone please check to see what resistance each pair of terminals has on a good ignition module? I get 84.8k on pairs 1-4 and 6-3, but nothing on 5-2. Unless I reverse the polarity on 5-2, in which case I get 84k. Can anyone confirm this with a good module?

[bbeck]

on another one that I have that went bad, I get 50k, 50k, 15k - respectively.

[gpse3400]

I wouldn't try to diag the ign too much.....If you feel the modula and coils are at fault I'd get another set from the junk yard. an 3400 enigne uses the same parts and are significantly newer.

[bbeck]

I got a new ignition module, and then checked the fuel injectors. They all ohmed out at 12.5 but one that was like 5 or 6 ohms. I replaced that and the issue went away.

[IanSzgatti]

sweet, good job buddy

[gpse3400]

eGGCELLENT

[bbeck]

It was terrible driving a car that was missing- it drove me nuts. Maybe I'll pull my a-arms and do my poly bushings this next week while my brother is home for spring break. We're going to try to put a 3400 and 5speed in his z24 convertible.

[Dxray]

So you replaced the IM and the injector?? Or just the injector? My car seems to be doing the same thing.

[IanSzgatti]

So you replaced the IM and the injector?? Or just the injector? My car seems to be doing the same thing.

im guessing here.. but im pretty certain he changed only one injector, the one that only had 5 ohms resistance.

[bbeck]

I replaced both the ignition module and the injector, but it was the injector that was giving me the problems.