Need some ideas/suggestions

[CPonyGo]

Okay I have taked to a few of you in person but thought I would post up before I just tear into the car...

symtom: when coming off a light or easy acceleration to semi heavy the car pull solid and hard and the A/F is right there.....BUT, when I go full wide open throttle the car lays down, just falls off and the a/f goes full lean.

some things I did...

Durty Kurty checked my adj fuel reg and was solid and held both at key off and at idle. note* we did not yet try a wide open throttle pull with the gauge attached yet.

We then checked some vacuum lines and checked the TPS for proper voltage all thru the sweep with positive results and proper voltage...

A couple of friends mentioned that it sounded like the fuel pump was falling off under load...I did change the fuel filter(man that thing was heavy) and no difference resulted..

My fuel pump was installed about 12 years ago and is a 255lph pump and the car is primarily filled around the Milwaukee area...

The combo is a 347 with 30 lb injectors.. and the maf meter is sealed and in good shape.

I am headed out to prod around and check the plugs and lines again but was looking for other ideas before pulling out the tank again..

The car ran awesome and this just came on...great low end performance,just at 4grand or better at wide open throttle it loses power..

Ideas?/
TIA-me

[DurtyKurty]

Just thought of something else. Some sort of false reading from the MAF sensor could cause this too.

[DRK]

I would put a fp gauge on it before you drop the tank.

[DRK]

Just thought of something else. Some sort of false reading from the MAF sensor could cause this too.

You can pull the plug on the maf and run it. It will be in fail safe mode but it would pin point a bad maf.

[CPonyGo]

Thanks Jesse...yeah I ama going to exhaust all options before dropping the tank...have read with regularity that pumps work at low load but not under full load...so I will check around..thanks man..

Thanks Kurt

[CPonyGo]

Bingo...Thanks Kurt and Jesse....while the car was cold I ran the lines again and the maf connections..took the car out and it still did it...came home and disconnected the maf and that did the trick...rough idle but she would go wide open throttle with a slight miss-read very slight...third gear to forth wide open was stellar...as was a side step off idle in first and 30 ft of marks and on a roll from second breaking them loose...so in all ranges of driving other than the idle it was back to normal.....so then I pulled over- hooked it up again to just qualify what happened and yes- it fell off again- no power..so it is for sure the maf...

now- would that lend itself to a bad one or a dirty one that needs cleaning or an outright replacement?

[Inspector13]

I'd start cheap. Try cleaning it first. What do you got to lose?? A few minutes and a couple of dollars.



Question for ya. Isn't 30# injectors pretty small for a 347??

[CPonyGo]

Haven't seen any a/f problems at wide open throttle save for this current issue

[DurtyKurty]

Theoretical HP on eight 30lbs injectors is 436 @ 100% dutycycle. So, I would say he's close but ok.

I say clean it with some MAF sensor spray cleaner first.

[CPonyGo]

yeah going to go get some now and see what happens...hopefully works...otherwise I guess its carbed for me...LOLOL

[CPonyGo]

cleaned...and works like a champ..car pulls seemingly stronger as well... thanks Kurt and Jesse

[Inspector13]

Yeah that is very true. I'm more used to carbs and don't know a whole lot about fuel injectors.

Glad you got it all sorted out.