1989 mustang gt

[msr110]

hi I need some help.i have a 1989 mustang gt .my mods are stock bottom 302.afr 165 heads,trickflow intake,trick flow stage 2 cam,trickflow pushrods,bbk 15/8 headers ,70 mm throttle body ,76 mm bbk massair calibrated for 30 lb injectors summit street strip dist.msd coil.'
stock computer,smog deleted,255 lb fuel pump,30lb injectors.my problem is car ran fine till I put the 30 lb injectors,255lb furl pump and massair meter on.when I start the car it runs and idles fine I go for a ride and when I jump on the gas car hits 3,000 grand and breaks up falling on its face bring it back to the garage and the idle jumps around 1200 to about 400 barely running I lift the hood and can turn the idle set screw and idle don't change I have had it turned as far as half open on throttle and it doesn't change .turn car off unplug battery hook back up it runs fine till I go for a ride does the same thing.i checked and set tps and idle the way you should what could be my issue this is a tuff one anybody.car is also a 5 speed tko 600 .

[John4cam]

Thats a lot of injector for your setup....id go with 24's. Could even be a bad injector too. You could try unplugging your maf when the surging starts at idle. See if that changes anything.

[John4cam]

Do you have a cel?

[msr110]

so your saying the injectors are the problem squirting to much fuel in when I hit the gas and the computer is going into limp mode.sorry didn't understand your question what's a cel?

[John4cam]

Check engine light? Id say the fuel pump has no effects on the issue at all. So it is one of three things. Possible bad injector/injectors. Bad maf/or not calibrated correctly for 30's. Or it could be a vacuum leak from the work you just did. Yes I think the 30's could possibly give you some drivability issues without a tune. Thats just my opinion. Do you have a set of 19# injectors to try temporarily?

[John4cam]

I have a set of 19's here in my garage id let you use to try...

[msr110]

yes I still have all original parts.the massair was brand new and the injectors are used also I do not have a adjustable fuel regulator

[msr110]

thank you very much for your help I'm going to rip into it and see what I can find have a very merry Christmas thanks.

[John4cam]

Thanks. you could try an adjustable fpr too. For your case id say you do need one.

[juice_man_86]

I don't see why the 30 lb injectors would be an issue. Sounds like the right injector with a little room to grow. As long as you're getting 40 psi, adjustable fpr should not be necessary. I'm still running the stock one in my 327 stroker and I'm running 42 lb injectors. I'd say it's either the maf, a bad ecu, or ignition related. I had a MSD ready to run plug in dizzy that would start up and run great for about 5-10 minutes. Then the car would just shut off. I changed the ignition module 3 times. Turned out to be a bad pick up in the distributor. I just put my stock one back in for now.

[msr110]

ok thanks ill give all these suggestions a shot I have put tons of money in this car and its been a nightmare.

[86GT]

Try your stock coil before you get too crazy, I've had 2 MSD coils go bad on black bess & boy
did she run bad when that was the case. I don't run that coil anymore, it might even have been 3
that I had go bad.

[msr110]

I have had that happen before on this car with a Mallory I went back to stock and it fixed it.the coil that I have now checks out good I tried it on my other car no issues thanks for the reply

[randomuser]

Adjustable FPR's are worthless on the 5.0 pushrod EFI engines. Adaptives will eventually correct/learn around any adjustments you make and put you back to stock.

[Rodeheaver's]

Chances are its the maf, what brand injectors are you using? We have had tons of issues with calibrated mafs, 1 in 10 will be close enough to work properly. you options are to keep trying different maf/injector combos or get it tuned. I could send you a chip with 4 different tunes burned to it to try.

[msr110]

I have a bbk mass air meter on it right now it's new it's calibrated to the 30 pounders.

[Rodeheaver's]

Double and triple check for vacuum leaks and any air leaks after the maf. Also make sure the egr valve doesn't have a vacuum line going to it. It should not have full vacuum. It should only have a line coming from the egr solenoid that the Ecu open/closed at a determined time.

[msr110]

I removed all the smog stuff.maybe I did to many things all at once.hard to diagnos ill check the things you remarked on thanks.

[randomuser]

If you're going to check for vac leaks, Google DIY smoke machine. Definitely the easiest/best way.