Still missing at WOT

[Redog]

Been searching the net for an answer, can't find one

Car stumbles at WOT. Had the 7X crank sensor replaced today, the 24X was replaced about 3 weeks ago (one of the wires was bare from rubbing)

It acts like its hitting the rev limiter. The 7X sensor was broken in 3 places (original, 147400 miles) now I can get to 4200 RPM before an issue (used to be 3500 or so)

On top of the sensors:
O2, replaced in May '13
Ign wires, 11 months old
Plugs 20,000K
coils all 3 & ICM, about 55,000 miles
Cam Sensor replace in March '13 (threw a code)
Header leak repaired in June '13
O2 sensor reading ok and low resistance between plug and PCM (.02 ohm)
WB reading well until WOT, then to 17.0:1

Not too pissed about replacing those two sensors, car needed them, but I just want it fixed

[jawa]

do you have hp tuners?

[AleroB888]

Wasn't there a thread on this already

[Redog]

COuldn't find it. posted this from my phone.

My buddy was telling me when he had his 97 Chevy 2500, it was holding gear too long and really lagging on accel, turns out his fuel filter was clogged, replaced it and a few weeks later, his fuel pump went.

Going to see if that's the issue. This has been ongoing for a few years. Driving it was never a problem, but getting 41 MPG coming home from ASS, that's raising a very large concern for me.

Was thinking about upgrading to a Walbro pump if my pump goes. No listings for an Alero. Do I just get the universal?

[jawa]

i wonder whats causing it to run so lean that its getting that kind of mpgs,
run a fuel presure test and rig the guage so you can read it while on a test drive

[03glgold]

did you ever make the changes to your fuel trims that mfuller suggested?

[Redog]

I did, didn't help.

I saw on a Mustang Forum a guy was having the same problem and his fuel pressure was at 50 at idle but at 3500 RPM's it dropped to 23

[guiguilandry]

that's a sign of a failing fuel pump... or like you said clogged or pinched line/filter
did you checked it, I mean the flow, not just the pressure...
it's supposed to flow at least one liter in 30 seconds plus it has to keep the car running at idle...

you need this to test it or you can build your own redneck version with some fitting, a gauge, a hose and a pair of vise grip...
http://www.princessauto.com/pal/en/T...ster/8380040.p

[02AleroGLS]

One day mine was giving me a hard time starting and didnt have hardly any power above 4k and i thought maybe clogged fuel filter so i went and got a acdelco filter and changed it but right when i went to prime the system to start it i realized it wasnt pressurizing the system. Like i tried it for over 15 minutes.. Come to find out the pump had been going out and it was getting insane gas mileage the last week before it went lol

[Cliff8928]

Had that same thing with the fuel pressure drop under load on a L31 vortec truck (runs about 60 PSI on those). Of all things it ended up killing the trans because it was driven like that so long.

[Redog]

Cliff, that's exactly what happened to my buddy's 97 Chevy Silverado 2500.

It would hold the gear so long, then finally catch the gear after sitting at 5500+ rpms for a long time

[Shiwnath]

Originally Posted by Redog

Was thinking about upgrading to a Walbro pump if my pump goes. No listings for an Alero. Do I just get the universal?

The F-Body racetronix kit is what the Grand Am guys use IIRC. Check www.grandamgt.com. I know I've seen the answer on there before. Also I think Milzy might have a walbro fuel pump upgrade listed for the N-Bodies.

Edit:
Milzy link http://www.milzymotorsports.com/walb...gm-v6-engines/

[Redog]

Just reading up on the Racetronix kit. AleroB888 has a pretty decent write up on it.

I think I'm going to get it, just not now. I could buy it now, but I want to pay cash for it

Was reading AleroB888's thread and Spy's right here.

Do I need the upgraded wiring kit? Run another power line? Do I need anything else besides the red pump thingy?

[sleepyalero]

I believe just the wiring kit he said in the thread, he gave a part number.

[Redog]

The wiring kit includes another wire for power and ground. Not that it's a big deal, I know where I can get power, but is it neccessary?

[sleepyalero]

Hopefully b888 can help cause i have no idea

[a.graham52]

in my honest opinion, you should get yourself a fuel pressure tester with a hose to attach to the fuel rail, like previously said, check your fuel pressure, rigt it while driving (iv stuck it under the wiper blade before) and check yoru fuel pressure at idle, cruise, wot. if your pump cant keep up, then you wont have proper pressure. so many people just throw stuff at thier vehicles without ever testing

[jawa]

EXACTALLY properly diagnose the car and save money at the same time
its a win win situation there

[Redog]

Replaced the fuel filter today. It was old anyway. Car has better throttle response but still does the missing crap at WOT.

Talked to my mech today. He did the filter because the way my exhaust is set up, I could not get my fat hands around the Y pipe which is directly under the filter Had 2 tires dismounted while I was there, and it was $40 for everything so, yeah.

His good fuel pressure gauge is broken so he couldn't chek the pressure today. He does what everybody is saying and brings the gauge into the car and drives it. Don't know if I can do the pump on the ground, but I'm going to upgrade so,

[Redog]

Finally figured out the problem. I think I updated this in another thread but I'll update this one too.

It was the ICM!!

I replaced the ICM back a few years ago because I thought it was a problem back then (the car didn't agree with the plugs) and replaced it with a cheap one from Hon Kong.

I watched a video on YouTube and the ICM is supposed to have 3 small scuffs on the bottom plate. Those "scuffs" are actually a 2nd solder inside the ICM that will provide a longer life. The Chinese one, no marks, the orginal one had the 3 marks.

Car runs great now! Even the fuel curve has improved