OK, so normally I would tear into my car myself before asking any questions here but I don't have the time or resources to do that for the next year and a half so hopefully I'll get some quick help here.

I suspect a fuel issue with my car, and my first thought is either my fuel pump or filter. After my car arrived in Korea from a month and a half of no activity my gas mileage has be cut in half (down to about 110-120 miles per tank now), my idle is ****ty, wideband reads odd at times while cruising and car bucks (rolling in second at low RPM does this sometimes, a/f drops to 11.5-12.5 and car hesitates/bucks), and my car has even stalled at idle 3 times now.

I have limited tools and the closest hobby shop to me is about an hour drive, so I'd like to get a VERY good idea what the issue is so I don't waste more time than I have to.

Fuel pump is a Walbro 255 that I installed back in May-ish 2006. Only other fuel mod is PTE 1000cc injectors.

Thanks in advance for any help.

 

could be bad fuel, clogged injectors due to bad fuel . my fuel pump was went bad it was my fault for running the car low on gas. i started running very lean and the pump got very loud

 

^ Thanks... forgot to mention the pump got noticeably louder. It was the first thing my wife noticed when I picked my car up a few weeks ago.

I had to put a few gallons of 92 RON in since I was low on gas and was lead to believe Camp Casey had 98 RON at the pump. I definitely did NOT boost and still haven't until I'm done with my current tank of 98 (and until I fix the issue).

 

Start cheap. New plugs and injector cleaning first.

 

I wonder if my MAF sensor might be f'd.

 

Do you haz a tactrix cable? So your closed loop operation is acting up? Take a look at your MAF and make sure the honeycomb is still intact. I do not believe it to be a fuel pump because of the rich AFR's, however it could be the ECU attempting to compensate. Any CEL?
Is the fuel there by any chance leaded? Could have taken out an O2 sensor.
With out tools, there is no easy answer sorry

 

any updates?

 

ya could be pump or injectors also the tune though you say it just got back from korea and depending where it was and the humidity and elevation ect all that will effect it! good luck!

 

OK so I'm definitely still having this issue, just haven't had time to really do much about it except get new plugs and clean my MAF.

There's no boost leaks at all. Honeycomb is still intact. I ran a few bottles of fuel injector cleaner with no luck.

Next on the list is to check fuel lines for a leak (very doubtful, don't smell fuel), check for clogged filters (recently cleaned air filter, have a new AMSOil one that's going in, need to check fuel filter), check injectors (not sure how though other than visual), and pray to the car gods.

As far as logging is concerned, what should I be looking for? What items should I log when checking for an issue like this? I'd guess at the very least o2 sensor and MAF voltage, but what else? Log at idle or cruise?

HALP

EDIT: Also no CELs.

 

fuel filter?
fuel pump dying?

no cels, so no o2 sensor dying.

since you said the walbro is louder i suspect its dying or something is stopping it from receiving proper voltage.

 

I had/have a similar issue. My car was tuned and running 93 and 100% meth. after a while i notice the wide band reading almost a full point lean and the pump was extra loud. I swapped a new walbro but still have issues somewhere. Plugs look ok, but I am going to swap those also. Right now my car is making mediocre pump gas numbers while still running the meth, so it leads me to believe there is a fueling issue somewhere. I have to check the injectors by replacing them with another set of EVO9. let me knwo if you have any progress!

 

No progress yet. I might try the fuel pump rewire to see if that helps. Next will be the filter then if both fail just swap in a new pump.