865.0trunk

if i am hard on the gas the car will cut out at 3000 - 4000 rpm. feels like a rev limiter or something, if i am easy on the gas it will rev right to redline. i changed fuel pump, map sensor, adjusted tps. plugs wires cap rotor. can anyone help me i am getting really pissed off with the car i cant figure it out. its a full 88 drivetrain in an 86. dash harnesses computer engine etc. someoen help

Grimace5.0

I don't know jack about EFI but get with Joel5.0 he knows a bunch of tests and diagnostic stuff......

865.0trunk

thanks hopefully he sees this post. im gettin really pissed off with this car, when it hits about 3000 rpm it just is dead and starts jumping,

knucklefux

if your check engine light isn't on, it's prolly not a problem with the injection system. then again, it sounds like there's a problem only when the ecm refers to the wot table for the proper amount of fuel. what happens if you go past 4000, then floor it?

865.0trunk

if i got past 4000 and punch it, it will die still.

knucklefux

it's something related to wide open throttle. you may need a new tps, or something. have you done any mods to the engine? i mean heads, cam, intake, throttle body, anything?

Joel5.0

Suggestions:

1. http://www.themustang-net.com/eec.shtml but do a codes clear first and a couple of test drives with the condition.
2. After getting engine at op temp, check TPS voltage output through its range, ign on engine off, for any voltage flat spots or spikes.
3. http://www.onr.com/user/pbooth/mustang/tfi.html also check the condition of the vanes rotor for any signs of rubbing against the stator sensor.
4. Check fuel pressure against time (leave the gauge hooked up) and watch for pressure drops.
5. Verify ground cables and wires, check if the symptom gets worse with load on the electrical system (headlights, A/C, wipers...)
6. Let us know the results of the tests.

I know.....a lot of testing, but believe me....it's cheaper than throwing parts at it.

865.0trunk

i have long tube headers and a flowmaster exhaust. gutted cats and H pipe. everything else is stock. if i have been driving the car on a warm day it will start to do it under easy acceleratoin as well, at around 2000rpm it will sputter a bit. the tps has a reading of 4.6 at wot so the computer must know its at wot. any more ideas man. please help !!

red302

I am having the same problem with my 93 GT. I replaced spark plugs, cap, rotor, plug wires, and fuel filter. Still had the same problem. Then I replaced my distributor and coil. Same problem. Replaced my TPS sensor. Same problem. I checked my fuel pressure which was at 40 at WOT and my fuel pressure regulator for vacuum and for leaks. The regulator and whole fuel system was fine. This past weekend I set the timing perfecly at 10 degrees and cleaned my fuel injectors. Same problem. So I gave up and went to a Ford dealership and a technician told me to drive the car with the mass airflow sensor disconnected. I drove the car home and it pulled hard all the way up to redline. Look over and check your entire ignition system and verify that it is working fine. If it's ok then move on to your entire fuel system and verify that it is working good too. Did you replace the fuel filter? Also make sure that your TFI module (ignition module) is doing it's job too. I don't know how to check them, but I am sure someone knows or a Chilton or Haynes manual will tell you. Remove your spout connector and drive the car to see if it acts up. If you know someone who has old Ford 5.0 ignition parts try and borrow them and use them on your car so you can isolate the problem. I have been working on my car for a month checking this and that trying to find the problem and I hope the MAF sensor fixes it . Good Luck!!!!!!!!!