sputtering at high rpm. 90 lx .

[EFFURJDM]

hi guys so a month ago i bought a 1990 lx mustang. owner said was sitting since 04 , but would start it up ounce and awhile. on the oil filter it said 04-12-02 , so im guessing the tune up was a bit pass due.

ever since i got the car it would sputter up to 3grand at WOT . car starts up every time , and runs fine at cruising speeds in town or at a 75 mph on the freeway.

so i google and did what others did and suggested.
i have changed the
spark plugs
plug wires
oil
oil filter
gas filter
and cold air intake.
some one said maybe clogged cats , so i got a pyppes o/r x pipe and now the car revs up to 4g but then starts to run bad again after that.
car had very little gas when i got it and looked inside the tank seemed good.

so i can only think of fuel pump is going bad. i already dropped the tank to change the sending unit so would hate to do it again.

when i floor it and push it it makes a loud pop/bang i think from the back or from the right side of the front car .dont seem to be a back fire cuz u can feel it threw out the car. and i know what a back fire is , its not this. im not 100% sure what else it could be.

so i need help lol
any help would be great thx guys .

 

[93Cobra#2771]

1. Have you pulled check engine codes?
2. Have you checked fuel pressure at WOT?
3. Have you checked for vacuum leaks?
4. What is your timing set at?

 

[fivestangs]

The rubber diaphram in the fuel pressure regulator is probably shot, especially if it sat up for 8 years...you need to get a good mechanical fuel pressure guage on there and run the car up to WOT. Also, hindsight being 20/20 and all, it probably would have been prudent to change out the fuel pump considering how long the car sat.

 

[buddha93]

TFI, MAF, FP reg and pump as was metioned.........could be a lot of things from a car that has sat for that long.

 

[wheelhopper]

Send the injectors out to get cleaned as well.

 

[FISHTAIL]

I echo the above sentiments, but your description sounds to me like a fuel problem. I'm guessing either your regulator or your pump are shot (or both).

 

[wheelhopper]

^Mike, don't you think he should get a TwEECer?

 

[FISHTAIL]

lol, everyone should get a TwEECer! :burnout: