Misfire/backfire issues.

[Losiracer2]

do you still have the factory intake manifold? I would check your EGR passages to see if they're clogged.

That'll cause a misfire between 1500-2000rpms. Happened on my F22 91 SE's EGR system, so I bypassed it for now with a blockoff plate.

[Mike1357]

Well I've never had a new ignition control module in both scenarios. Because the misfire happens randomly on the uprev and down the air fuel ratio changes a bit. For the sake of conversation let's say it's half throttle normal driving, 13.4 give or take 2/10. I've had dirty injectors in the past and usually it only misfires when the car is cold and I have much more lean fuel ratio readings. The only fuel related thing I can think is the fuel pump is starting to go but every time I check my under hood gauge it reads where I expect it to.

In regards to the manifold, I'm running a skunk 2 intake manifold so no EGR things to worry about unless the passages in the head can get clogged up and cause that. I also experience the misfire at all rpm and throttle ranges.

Any other opinions on what distributor to pick up?

[Mike1357]

I decided on picking up a new TD60U off of Rockauto. Unfortunately when the distributor arrived on Thursday, I opened up the box and the cap was completely demolished and the rotor was damaged. After contacting Rockauto, they told me they would send me a new one right away and that I did not need to ship the one that I received back. I decided to remove the ignition control module from the damage distributor and popped it into my car. Unfortunately this did not seem to solve the issue I'm having. With the ignition control module ruled out, I can only hope it's one of the other two sensors inside the distributor that have failed.

[Grumpys93]

I’m kinda lost right now waiting to see what the new distributor reveals. That’s nice they let you keep the old distributor. There’s a lot of good parts still on that distributor.

[Mike1357]

New distributor is in, unfortunately there is no change in misfiring. I feel like an idiot just throwing parts at an issue, though ultimately the plug wires were old as all get out, the plugs were old, and the distributor was leaking oil inside. Yes, these were problems that needed to be addressed anyways, but it's annoying. I guess Raf99 was on the right track with the fuel being the issue. Being that fuel pressure is maintained, I don't think the hose in the tank from the fuel pump to the sender bracket is split. The only other thing I can think of is a dirty injector, but this is nothing like the last time I had a dirty injector. I guess I need to send out my spare set of stock injectors to get cleaned and we will go from there. I also don't think it's an issue with the timing belt as it still has low miles on it and, age wise, is only a few years old. I also already did the H23 manual belt tensioner so to think that it jumped timing is a bit of a stretch for me. At this point I'm at a bit of a loss. I may also do another compression check to confirm my findings from the first time, but I'm not expecting anything to change there.

[Mike1357]

I was able to find a guy right near my job that cleans and flow tests injectors same day. I ended up installing them today and, lo and behold, the car runs perfectly now. It now runs smoother than it ever has before. I'm glad I've finally found the solution to my problem, however I am annoyed with myself at wrongly diagnosing this in the first place.