idle problems

[Eggdrop]

ok, along with the issues i am having with the fuel, it seems that there is an issue with the idle. the car will idle fine the moment i get her started, after like 10-12 min the idle will start to drop a small amount. you can hear the exhaust burp a bit as its doing it. eventually it will start to gradually go down until it shuts off. some history: i replaced the maf, o2 sensor, and the car gets flooded with fuel on all cylinders. i have a walbro with stock fpr. i have already been through 3 sets of plugs. also, while i was revving her i noticed that i could not really get past 6000 rpms. when i would get that hight the car would really start popping and backfiring. lots of smoke from the exhaust and smells like gas is everywhere. whats going on?

[SPOOLDU]

ok, along with the issues i am having with the fuel, it seems that there is an issue with the idle. the car will idle fine the moment i get her started, after like 10-12 min the idle will start to drop a small amount. you can hear the exhaust burp a bit as its doing it. eventually it will start to gradually go down until it shuts off. some history: i replaced the maf, o2 sensor, and the car gets flooded with fuel on all cylinders. i have a walbro with stock fpr. i have already been through 3 sets of plugs. also, while i was revving her i noticed that i could not really get past 6000 rpms. when i would get that hight the car would really start popping and backfiring. lots of smoke from the exhaust and smells like gas is everywhere. whats going on?


Ok, so you just solved the mystery to you're own dilemma. You have a Walbro fuel pump, I'm assuming a 190LPH or 255LPH and your stock FPR...you're overrunning your factory FPR thus the excess fuel in your cylinders, hence the crappy idle. Get a FPR that rises at a 1:1 ratio, like an Aeromotive, and set your base FPR properly and post back with the results.

[SPOOLDU]

The reason why it's idling fine at warmup is because your car generally runs richer to get the engine warmed up...thanks to your coolant temp sensor.

[NemeGuero]

Actually, you don't need an aftermarket FPR to run correctly with a walboro.

It sounds more like an exhaust leak to me. Especially since you can't rev above 6k. Make sure everything is tight, check gaskets.

[SPOOLDU]

Actually, you don't need an aftermarket FPR to run correctly with a walboro.

It sounds more like an exhaust leak to me. Especially since you can't rev above 6k. Make sure everything is tight, check gaskets.


Your right, I forgot to mention the exhaust/pre exhaust leak which would definitely be a cause for this type of issue.

So you think the factory FPR is sufficient for a higher-flowing fuel pump? In most cases, a higher flowing fuel pump generally over-runs the stock fpr which was designed to deal with a lesser-flowing fuel pump.

[Eggdrop]

i got a sard fpr. im just waiting on the adapter bracket, fittings, and the pressure gauge. you really think theres an exhaust leak? i just had that thing put on. i guess ill have to check that too. i believe the stock fpr is def being overwhelmed cause of all the flooding. i didnt know that could also be the reason for the bad idle.

[SPOOLDU]

i believe the stock fpr is def being overwhelmed cause of all the flooding. i didnt know that could also be the reason for the bad idle.

Really? Hmm...:bite:

[NemeGuero]

Yes I do belive stock FPR is okay. Several guys on Ka-t.org are running stock FPRs with their set-ups. I know Jeff240sx was.. I am... GroundZeroMotorsports was on their 15psi ka-t.

EDIT: however, your FPR could be going bad.
and yeah, exhaust leak would be my first guess.