Car does not run after swapping injectors

[92stanglx]

I have a 92 that I just put a new 331 w/ a Vortech in. For the initial breaking period I was running the car with 24lb injectors (keeping it out of boost). The car ran really well. No problems what so ever. After putting about 900 miles on it I decided it was time to get it tuned.

In preperation for the tune I swapped in a brand new set of FMS 42lb injectors and a pro-m 75mm maf which I had sent back to pro flow to be recalibrated. I also had my tuner burn me a base chip to work w/ the injectors so I could drive it to the dyno.

After installing all of this (inejectors, maf, and chip) I fire the car up and all it does is rev to 2000 rpms and then immediatley dies (w/o my foot on the gas). I pulled one of the spark plugs (just replaced them) and it was totally black.

At first I thought the chip was fcking something up so I removed it. The car did the same thing with or w/o the chip.

Does anyone have any idea what could cause this??

[RdRunnr]

Did you disconnect the battery for a while to reset the computer? Pro-m has been doing a bad job calibrating meters lately, so there is a good chance the calibration is off.

[92stanglx]

Yup, I disconnected the battery and double checked all of the connections. Still the same thing :weird: Someone else said my meter calibration may be off. What do I do about this? Send it back? Get a new meter?

[little2late]

damn not good news, i have a meter im getting recald also. if there is a doubt they should atlest check the calibration of the meter for free? you might have to pay shipping. hope you get it lined out. are you running an fmu? what kinda fpr?



billy

[92stanglx]

damn not good news, i have a meter im getting recald also. if there is a doubt they should atlest check the calibration of the meter for free? you might have to pay shipping. hope you get it lined out. are you running an fmu? what kinda fpr?



billy

Yeah, I have been posting on a couple of sites and a few people have said that Pro-M's recals have not been too good lately :weird:

My fuel pressure was around 41 w/ the vaccum line attached. I tried messing with it and it didn't make a diff. I'm not running an FMU.

My tuner told me that I should have went w/ a lighting MAF or and SCT maf. Appearently they work a lot better than the pro-m stuff. However, they both require a chip to work on a foxbody. You may want to look into these options before getting yours recal'ed.

[speedytang]

While the car is running keep your foot into it so it runs and unplug the MAF and see what happens. I would say a bad MAF circuit or tuned wrong for the injectors.

[92stanglx]

While the car is running keep your foot into it so it runs and unplug the MAF and see what happens. I would say a bad MAF circuit or tuned wrong for the injectors.

I tried pulling the maf connector. It runs a "little" bit better but still runs like crap.

[speedytang]

Then it is the MAF calibration more than likely. It is not sending back a correct signal.

[92stanglx]

Then it is the MAF calibration more than likely. It is not sending back a correct signal.

So how would I correct something like this? I just got this maf back from pro-m after having them calibrate it for 42's. If they f'd it up once would it be a safe bet that they would f' it up again?

I'm actually thinking about ditching the pro-m all together and going with an SCT big air maf. Have you heard anything good or bad about these?

[87DarkHorse]

my car needs to held @ wot to start,.. in order to shut the injectors off...(42lbs)..

have a pro m 80mm also running no fmu,just chip.

Randy~

[TheHawk05]

The MAF has nothing to do with cranking fuel...only comes into play once the engine is running......cranking fuel is controlled by the EEC only and it uses no input from the MAF to decide how much fuel to inject....in other words it's a set table. Having to floor it to get it to start with 42's or bigger is a common issue, especially when it's hot......if you have a chip than your tuner should have took care of this during the tune. Some guys get lucky and have no issues with 42's and starting problems....others like yourself (and me included) aren't so lucky. My car would start OK when it was cold, but forget it when it's hot. I had to tune the cranking fuel tables with my PMS and pull 40% fuel at cranking to alleviate the problem.

As for our thread starter....sounds to me like Pro-M messed up the re-cal......I'd call them.

[92stanglx]

Turned out to be a vac leak in the upper to lower intake gasket :teeth:

[sgtsin]

hmm i was gonna say fuel pressure base was set to high and car isn't getting enough air.. i guess a vacume leak starvs the engine for air too lol

[92stanglx]

hmm i was gonna say fuel pressure base was set to high and car isn't getting enough air.. i guess a vacume leak starvs the engine for air too lol

Yeah, at first I inspected all of the vaccum hoses and quickly looked at the intake. When I looked it over again I noticed a big peice of the upper to lower gasket sticking out of the side.