rocky_mtn_a4

Yea I think you misunderstood, it's not my truck. I'm just working on it for my mother-in-laws friend. He already went and bought the fuel pump because he's going off what the tech at this shop told him. Heres a partial copy of his invoice. The tech told him his fuel pressure was 40% of normal and expected it to last no more than 3 months. Well since then he's went to Vegas and back. Now he wants me to install his fuel pump...I'm tryin to figure out how much to charge him....lol

Wow...wouldnt that be convenient...can I get a second more convincing opinion? I would check myself, but the truck isn't here at the moment, and the guy wants to know what I'd charge him to replace it for him. He's got the parts, I just don't know how much work I'm gettin myself into, or even what a shop would charge in labor.

Can anyone tell me from experience if this model has the "fuel tank inspection cover" or does the tank need dropped to do the fuel pump? its the v6...

Well I can't get the code to return after clearing it...now its definately saying 55 no malfunction. But still running like crap, it may have given me till 4000 rpm now before it starts sputtering. The mode 5 live diagnostics just made me more confused...I'm definately getting blinking on the green led, but picking out a pattern is impossible. If you rev it, it flashes pretty much constantly, if you let it idle, it pretty much stays solid green and stabilizes. I think I'm done with this thing, time to pass it on to someone else who knows more than me =).

Quick update, I am now getting a 1 red and 2 greens indication of MAFS failure...I dont believe I was diagnosing it properly before...I'm sure I am now. Could this cause said problems? Still plan on doing the O2 sensor test and live diagnostics momentarily...

Well...checked the codes, all I get is 55, No malfunction. Checked plugs for fouling or gap issues, all good, checked timing, all good. Cleaned MAFS...no change. It's only when its warm. Sprayed all the vacuum areas and intake area with carb cleaner trying to get it to cough, no dice. Once it hits 3250-3500 rpms now its just backfiring loud as all get out through the intake/airbox. Would low fuel pressure cause this? He said he took it to the mechanic a couple weeks back and they said his fuel pressure wasn't exactly where it was supposed to be. I checked most the injector o-rings and they all look ok. No fuel leaks anywhere I can find. My fuel pressure gauge has a quick connect fitting for mopars, so I can't use it on this truck...Also, there's a noticable exhaust leak coming from the manifold area, not sure if this is playing a part.

Right on...yea I'll download that as soon as I get home from the hospital. I'm visiting my son and the hospital WIFI wont allow downloads. As for the CEL, I'm sure the FSM says, but I was curious at the moment if this is one of those vehicles that the CEL can be checked without diagnostic software or hardware? Like my Honda flashed the CEL for certain codes a certain amount of times, so no OBD was needed. If so, whats this process? Again I'm sure the manual says, but I can't download it at the moment. Thanks a bunch.

Ok so a little background info first...Truck broke down on me coming home from work, turned out to be the rotor. Replaced it, truck started hiccuping around 2500 rpms...done the distributor cap, fuel filter, used EGR valve cleaned real well from the junk yard, a couple new vacuum lines, new coil wire...problem is it runs fine when its cold, but once it warms up it starts running like crap anything above idle. Idle's fine, just once you hit 2500 rpms it starts bouncing the tach around and smells like gas profusely. If you lay on the throttle heavily while its hiccuping, it'll backfire loud as heck out of the airbox...any advice? No CEL...yea I thought that was weird too. It's actually a friend of mines truck and it's sitting in my driveway this weekend and I'd love to get it on its way. I have my own issues to deal with. =) Anyhow, I'm going to double check his work tomorrow with the fuel filter, check for vacuum leaks and whatnot. The fuel smell is whats tripping me out. That and the bouncing RPM's w/ backfire through the airbox. Has me perplexed. At first I thought it could be ignition, but how would engine temperature affect that? So I moved on to fuel or vacuum. It's almost exactly like it's running on 5 cyl. rather than 6. I'll check wires and plugs tomorrow as well.