Hey guys, i have a 94 mustang gt that is stock besides a k&n filter, o/r h pipe and 3 chamber flows. My problem is that under hard acceleration, the car momentarily pings then climbs through the rpm fine, but without too much power. The car is at sea level with the timing set at 9 degrees and i run 87 octane with a new fuel filter. I did a fuel pressure test and it idles at 32psi and jumps to 40 when i stab it, but then the psi goes down to a steady 30psi when i keep the throttle open . Without the vacuum line connected the pressure goes to 42psi at idle. Both my pump and regulator are stock with about 140k miles. Is this normal or is one of my fuel components going out on me? Also, a mechanic told me to pinch the fuel return line and that it should be around 80 psi; is this an accurate way to check the fuel pump? Any advise or comments would be appreciated. Thanks!
Is my fuel pump or regulator going out?
- Thread starter A95gt5.0
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CC'S95GT
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i believe your fuel system is still good to go. when was the last time you cleaned you maf? i ended up taking my k&n filter off and replacing it with a paper one because the oil in the k&n was contaminating the maf. also if the pinging continues try changing brands (cheap gas does this sometimes). min timing is supposed to be at 10btdc
Win
Legend
I can tell you you'll probably have to be changing that fuel pump sooner the later.
So my fuel delivery seems to be ok then? I cleaned the maf back when i went with a k&n filter not even 50 miles ago. When i bought the car like 2 weeks ago it had a very very dirty filter with a dirty maf that made the car ping really bad after 3500 rpm. It is of course much better now, but hearing the engine ping still makes me weary. Many people say that is normal for 5.0's, but damn i hate to hear it...
The fuel filter was changed last week. The reason i haven't put 91 octane in it was because i didn't see the need. The car is basically bone stock with 9 degrees timing, but I will put premium next time i fill up and see what it does. Also, should i add a bottle of fuel injector cleaner on my next fill up, does that stuff really help? If so, what fuel injector treatment do you guys recommend? Thanks
95 svt cobra
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when i do used fuel injector cleaner i use the chvron stuff, or lucas products. most of the other stuff is a gimick
CC'S95GT
Post Whore
paul is right. i had forgot about the summer blend too. keep us posted on the progress and if the increased octane helps or not. i have a stock motor with 160k about 10 to 12 deg. timing and i use the cheapest gas around withou pinging. maybe your balencer has shifted and your timing is off now. IDK
My car was tuned on 93 octane out in NC and I haven't changed anything on it since bringing it to Cali. HONESTLY, I haven't noticed any difference EXCEPT when it gets to 180 degrees (full operating temp) it starts to knock a bit at WOT...HOWEVER!!! (I'm so pumped about this) there is a station around the corner from my place that sells 111 Octane Race Gas out of the PUMP at $7.77 a gallon! I'm about to make the switch.
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