Hi,

I have an 89 Formula 350 tpi.

It was running fine one day, then the next morning it started ran for a few seconds then sputtered and died.

I cleaned and adjusted the IAC. I can get it to run if I hold the throttle mid-open and keep nursing it. It surges and almost dies then surges/backfires.

After it's warmed up it will run OK, but not great.

I checked the fuel pressure -it's fine.
I checked the injectors - they're ticking away.
I spent all last night changing the fuel pump and filter thinking it must be somehow bad.

It did not help.

No codes are being stored.

Could this be a MAF failure?

How do you test for it?

Any other ideas?

regards,
-Brent

 

Even if there is no code for the MAF it can still be bad.
Check it with a MT2500 or equiv, go to live eng data and watch the Grams of air per second, it should be around 5 to 8 at idle and it should be moving around very very quickly. As you increase Throttle angle it should also increase.

Lightly tap on the MAF with a small screwdriver and the engine idle should not change, if it stumbles or varies, its possible it can be bad.

I would ohm out the injectors or watch their wave form if you have access to a Vantage.

 

Vacuum leak by any chance? Mine backfired until I got my leak plugged.

 

Guess what - It is my MAF.

I uplugged it and the car runs "fine" but not great. Throttle response is not quick, but the big problem is gone.

THANKS!

Now, what is a good MAF to buy. Mine is the original Bosch with screens removed.

Is there really a notice-able difference in buying different brands?

 

They're all going to work the same at 1st, Its really in how long they last.
GM's are going to last the longest and cost the most.
Some may dis-agree BUT, I would leave the screen in ! Any foreign matter that gets past the filter and comes into contact with the heated wire can cause failure, and for the very small performance gain (if any at all) its not worth it. The screens are there to straighten the air flow out so it moves across the heated wire 'evenly' and with no turbulance.

 

I agree - and it makes sense that the screens smooth the flow. I could imagine more erratic air measurements without them. I did this about 10 yrs ago when I was in tinkering mode. I'm leaving them in this time around.

 

Glad yours was an easy fix, Now come and help me with my problem , lol.
https://www.thirdgen.org/forums/tpi/...e-my-fuel.html

 

I found a Venom MAF 847-573 on Jegs for 150
Garantelli 350100 for 300.

Has anyone bought a Venom?

The don't have a picture.

 

I'll reply to my own post...

The Venom maf is a universal maf sensor- needs to be wired to the computer.

I guess the only option is the Granatelli that I can see in jugs or summit - it is adjustable, so that could be useful in the future after mods etc.

 

Just for closure to the original problem...

Installing a new MAF fixed the problem.