Need help...car won't idle after fuel pump hotwire

Installed walbro and fuel pump hotwire kit the other weekend and now the car won't idle for shit. I have to adjust my maftpro mainscale to +35 for it to even idle at all. It should be -35 for 550cc injectors...had the battery unhooked the whole time during install and rewired the maftpro and heatshrunk everything during the process. I'm certain the wiring is good since I unhooked one wire at a time and heatshrunk it back together.

No fuses are blown, and another odd thing...now my fuel pressure gauge shows 0psi idling, but sender could have coincidentally crapped out. If I even touch the throttle the car will sputter and die. I'm out of ideas, the walbro is running properly and I relayed into the blue/black wire from the pump. Ideas please, thinking ECU may have shit the bed somehow since the ECU kept resetting and turning on the a/c everytime the car was started after walbro install then went away out of nowhere and doesnt reset the a/c when the car is started anymore. What do I check first?

Bump really need help with this one

It's been a while but little to no fuel pressure can be why you cant get it to increase RPMs at all and would also explain the crappy idle. Did you test the pump beforehand? Any chance you could test just the pump? Pull that bad boy out and do a hotwire to it. I'd be looking at the pump :(

Ya that was my next plan of attack. I can hear the pump running but it could be that it isn't securely in the hardline feeding up the hanger assy. Still odd my fuel gauge reads 0psi tho I'd think even if it wasn't in the hardline all the way it would build some pressure lol

Not overrunning the stock FPR? Does it smell rich?

Smells very rich yes, and forgot to mention I'm not on stock fpr. I have an A1000 AFPR, and it was adjusted righ at 43psi before I swapped the fuel pump. Strange.

Im thinking either MAFT-Pro or ECU.

It sounds like youre flooding it with fuel actually.

Yeah, smells like it's flooding too. I just don't understand how simply swapping the fuel pump would cause the ECU to go out or mess with the Maftpro. I even went as far as to put the base setup back into the Maft to see if it was a setting getting screwy. No luck, and the car ran just fine before on the same tune and everything else the same :shrug:

I would investigate 0 psi fuel pressure 1st. Is it a gauge in line w/fuel rails or in cab? Plugs getting soaked? I understand u r blow-thru but sounds like same/similar to issue I had when mafs was bad.

Sent from my Eris using Tapatalk

Quote:

---

Originally Posted by Roybatty

I would investigate 0 psi fuel pressure 1st. Is it a gauge in line w/fuel rails or in cab? Plugs getting soaked? I understand u r blow-thru but sounds like same/similar to issue I had when mafs was bad.

Sent from my Eris using Tapatalk

---

Yeah it's an in-cabin gauge attached to my AFPR. I'm starting to wonder if coincidentally the gauge sender went out or something. Haven't pulled plugs yet but will do that and check. I wouldn't think anything would be wrong with my maftpro, but you never know. TPS and all other sensors seem normal in the monitor screen so I would assume the maftpro and ECU are still ok. Could be that the pump just isn't seated to the pickup tube in the hanger assy, thus barely supplying enough fuel to idle the engine but not when any further fuel is demanded by applying the throttle pedal, and possibly low enough to simply not register on my fuel pressure gauge.

The ECU has nothing to do with the AC resetting itself. When the battery dies, the AC resets.

I would first test voltage at the pump, then test the pump itself (pull an injector one by one and see if they each squirt), then check on the 0psi FP reading. I would also recheck the AFPR if the injectors aren't flowing, just to make sure.

Quote:

---

Originally Posted by jba3

The ECU has nothing to do with the AC resetting itself. When the battery dies, the AC resets.

I would first test voltage at the pump, then test the pump itself (pull an injector one by one and see if they each squirt), then check on the 0psi FP reading. I would also recheck the AFPR if the injectors aren't flowing, just to make sure.

---

I was always under the assumption that whenever the battery was pulled for extended periods of time the ECU was reset, and kicked on the AC on startup, until you manually push the OFF button on the AC. The odd part was that the AC would kick on everytime the car was started, even after I would turn the AC off. The battery being attached the whole time. I was still finishing up some wiring of auxiliary gauges at the time tho, so a fuse being out was likely the culprit. I intend to take out the pump and make sure it is securely seated into the tube running up the hanger assy and check the voltages it is seeing while I'm there.

Quote:

---

Originally Posted by mh3kgt

The odd part was that the AC would kick on everytime the car was started, even after I would turn the AC off. The battery being attached the whole time.

---

That sounds like it's lost constant 12v. I'd check that fuse, and also check to see if the radio resets itself (loses channel settings) every time you shut the car off.

Quote:

---

Originally Posted by jba3

That sounds like it's lost constant 12v. I'd check that fuse, and also check to see if the radio resets itself (loses channel settings) every time you shut the car off.

---

I believe that part of the issue is fixed. The AC no longer resets, and I'll have to double check the radio settings, but I think it is keeping memory now as well. Likely just a fuse I had pulled to wire up all the rest of the gauges. Now on to the fuel situation lol

Quote:

---

Originally Posted by mh3kgt

I believe that part of the issue is fixed. The AC no longer resets, and I'll have to double check the radio settings, but I think it is keeping memory now as well. Likely just a fuse I had pulled to wire up all the rest of the gauges. Now on to the fuel situation lol

---

Ah, good, the constant 12v wouldn't normally affect fuel since ignition 12v works. Try the voltage test at the pump, etc, like I posted above, let me know if it works.

Will do. I know the pump is at least getting power and running when the car is on. Those walbro's are definately louder than the denso I had in before. I checked with a test light after hooking it up, and had power at the pump. Not sure how much voltage it is actually getting, but enough to run. I'm really thinking it came out of the hardline on the hanger since fuel pressure seems to be so low. Still baffles me that it smells so rich, but probably bacause I had to add a shit ton of fuel on the maftpro just to get it to hold an idle and not die.

Pull the pump and check the voltage at the connector. I use mmcd to turn the pump on for diagnostics, but you can turn the key if necessary.

Success!! Pulled the pump and the o-ring wasn't seated at all, was resting on the neck of the pump. Reinstalled and now the car will idle correctly. Still only showing 20psi fuel pressure tho but that can be addressed easily enough I'd hope ;)

Sounds like your 0 fuel pressure is real. Check the o-ring and or other aspects of your fuel pump install. If that's all you did and than had problems. Don't start looking elsewhere for issues as that makes no sense at all. It will have been caused by the "last" thing you did. In this case the pump install.

Oh well, posted too late. But is good for others to read the logic.

Yes thanks for the reply GTwizard, I think I have it mostly sorted out now, although I may end up modifying the hardline and cutting it up higher so that I can just use some fuel line and attach the pump that way with some clamps so I dont have to worry about that darn O-ring anymore...I'm still only getting 20psi fuel pressure from what I can tell.