1989 Mustang 5.0, Sputters and Smokes at High RPM

Discussion in 'Fox 5.0 Mustang Tech' started by roadrunner_taz, Apr 29, 2008.

  1. I have a 89 5.0. Mods are: aluminum heads, rockers, headers, 75MM TB, Fuel pressure regulator, 190 lphr fuel pump, hypertech chip, 373 gears.

    My question is my care runs great under normal conditions but when I really get on it and put it to the floor it feels like a sputtering or no power at about 4000 RPM. I notice this a little in 3rd gear but it is really bad in 4th gear. If I let up on the throttle say 3/4 throttle I actually will have more power then if it is all the way to the floor. Also when it bogs down like this I notice white/blue smoke coming out the exhaust and can smell that it is burning oil.

    I initially thought it was a lack of fuel problem so I added the bigger fuel pump and changed the filter. This did not help. Engine is not pinging but I decided to try to set my timing from 14 and to about 10 and that did not help. I had put in new plugs and wires when I put my heads on so they are pretty new.

    This is a new problem that just started so it is not from the new head install. I also checked my head gasket and that is not the problem. Please Help!!!
  2. i have had white smoke come from my tailpipes and that means blown head gasket in most cases... its burning antifreez..

    i HOPE i never see blue smoke because that more often than not is an indication of oil burning in your combustion chamber:notnice:

    your problem under WOT seems like mine when i had my nitrous jets in vice versa... meaning too much fuel and not enough n2o to burn well.

    i switched the jets and it ran like a bat out of hell.... i think your getting too much fuel in there some how.... but i dont know how. what size injectors??

  3. just stock injectors which is 19lbs I think. I have read some other stuff and I am going to try a colder spark plug and a new cap, rotor and coil
  4. For the record please don't post the same thread in multiple forums
  5. i had the same problem with the breaking up around 400 rpm,, try using the brass cap and rotor,,, that was my problem... i had swapped the rotor cap from my brass one to the aluminum one because thats what i had sitting around and the brasss one was bad,,,, took it out for a drive and it would break up @ or around 4g's.. i went straight out and bought the brass one again and it would run up to 6g's without a problem .. try that out i think it will take care of your issue
  6. Why are you bumping all of the old threads, thunderstang? Please watch the dates, I'm sure the problems have been solved for years, by now. :nice: