Ok, I'll pick up a set here soon, and go from there. Is yours doing the same thing?

 

No, just part of a project engine and they didn't look wonderful. I cleaned them all and figured $12 or so was cheap to get them back in decent shape.

 

Sounds like o-rings are in need of replacement; either that or something is not torqued down in the correct sequence.

I lean to the o-rings; probably shrinking once getting up temp a little bit..

This would be my guess..

 

I'm hoping it is the o-rings. Like I said whatever the issue is it fixes itself within a few seconds then it never has any more issues. I'll try and get them replaced this weekend and I'll keep you guys informed of the outcome. Thanks a lot for everyone's input and knowledge

 

Alright guys I may have solved the issue. I'm keeping my fingers crossed anyway. I took the IAC (idle air control) valve off and noticed it had quiet a bit of carbon build up on the end of it. I took some throttle body cleaner and cleaned it up. I also cleaned up the cylinder housing connected to the throttle body which had carbon built up as well. I put it back together and started it up. It idled fine and took it for a small test drive. It never misfired nor bogged down! I hope this is a permanent fix to my problem.

 

If that doesn't do it, put a fuel pressure gauge on it and watch the fuel pressure when it starts running badly. It sounds to me like it may be starving for fuel. If the injector o-rings were leaking air, I would expect the problem to be worse at idle, when vacuum is high and airflow through the engine is low.

 

Well I tested it again today and it done the same thing. I can't figure this thing out. So you thinking the fuel pump may be going? What I can't understand is why it normalizes itself after a few seconds and won't do it again until the engine cools back down. I'm lost.

 

Only way to know if the pump is losing pressure is to put a gauge on it and drive it. If you don't have one, I think some place like AutoZone might loan them out.

 

Okay it's worth a shot. You think a failing O2 sensor may cause this problem?

 

I unplugged the O2 sensor and started it up. No help, still doing the same thing.