Running Rich and Cutting out Under WOT

[habitatguy187]

Ok, so I've searched around and haven't found a definite answer. My car seems to run rich (smell of gas) and sometimes idles horribly, sometimes idle surge, sometimes idles fine. Anyway I changed plugs and wires and properly gapped. Checked for boost leaks, I have a small vacuum leak in the hose that you tap into for a boost gauge, but besides that everything's fine. Under boost between 5000-5600rpms my car gets some kind of cut, it's not as rough as fuel cut, but it definitely cuts out. Are these even related? I've searched all over and haven't found anything but more guesses. thanks

 

[dale187]

How about the wires. What kind of wires are you using?

 

[slowstang]

As said in MANY other threads before...

Before you go throwing parts at a problem, invest in some sort of data logger. -That should at least steer you in the right direction. Right now you are flyin blind without any sort of knock or A/F monitoring.

AMEN! - This will help you diagnose whether or not it's a MAF or O2 problem.

On a second note, my hacked 1gmaf was horrbily inconsistant with reading the airflow. It would be peg out the computer fuel trim adjustment on both the lean and rich side on different days of the week. It would also occasionally do the cut out like you describe. 2g MAF and my own eprom tuning got rid of most of my running rich/lean issues.

 

[habitatguy187]

How about the wires. What kind of wires are you using?

I'm not sure some $35 wires from o'reilly. And my friend brought over his 1g maf and it's in my car now and still cuts/idles bad. Someone said that a vacuum leak could cause this. Is that true? My gauge shows -15-16 at idle.

 

[Splitpi]

A boot leak / vac leak will cause it run rich ... which is what your problem sounds like.

 

[dale187]

Yea you might havea vac leak and +1 on the vac leak causing it to run rich. Check all your vac lines and make sure all the lines are fastened decently. I pull 20-21 on my 2g. Don't know if there is much difference between 1g and 2g

 

[habitatguy187]

A boot leak / vac leak will cause it run rich ... which is what your problem sounds like.

Ok I'll try to fix that today and get back to you guys.

 

[habitatguy187]

Ok I fixed my small vac leak, then looked at the taboo vacuum diagram and found that I didn't block off my egr lines, nor the line on the intake canister, it also said that there's a line on the 14b but I couldn't find it anywhere, unless they're talking about the j-pipe nipple.

Anyway capped those three off and on the way home for lunch the car ran muuuuch smoother, didn't smell like gas, and accelerated much better. boost gauge reads -17 at idle. But I still get the cut in the 5000rpm range. Could this be the biss screw leaking? Because I don't have the little rubber thing that covers it.

Thanks for all your help so far guys.

By the way I've never had a problem from the biss when doing a boost leak test, just wondering if it could cause fuel cut, either way I'll replace the O-ring.

 

[habitatguy187]

Don't know if this helps but it seems to run worse after I start it when it's warmed up. I usually have to give it gas to keep it from dying... Sorry for the consecutive posts I just want to give all the info I can. Thanks

 

[rock1t]

Try plug wires. Had this problem twice now,did plugs and wires and the problem goes away.

Ha, I have this problem, but I also have a lot of mods. Plugs are weekend change for me on the 7s, new ngk wires to. I fixed my fuel cut between 5-6 by richening the **** out of injectors. Now its just between 65-7k, the more fuel I add the better it runs, but I am always afraid of washing the cylinder walls with fuel. ARGH. Oh yea I am running 10.1 fuel/air ratio. Ha.