Hey y'all, trying to help a friend of mine who just bought a fox get her up and running right, having some trouble with something I haven't dealt with before, and can't find much online to help me anywhere.
1990 GT, 5.0, Gt40p heads, upper and lower intake, B cam, BBK Longtubes. Previous owner replaced TONS of little things here and there, new plugs, wires, cap, TFI module, MAF sensor, MAP sensor, TPS, fuel pump, and tons more that are great but not really relevant. It all looks very new, and the engine build itself is relatively new. This was a good deal where the guy mostly just got tired of fooling with it despite heaps of new parts, and hardly touched it from what I can gather (even the engine paint looks good!)
Anyway, here are the symptoms. The car idles good. IAC unplugged, spout unplugged, the car surges a bit but mellows out to the proper 750 RPM or so. Got the TPS dialed in, timing seems normal (don't have a timing light on hand but by feel, it seems fine, and was set previously). With everything plugged in, it idles about 1500 on startup then begins to go down to 1000 or so before it suddenly dies on me.
Only thing is, it randomly just shuts off. no surging, no hunting, just dead stops as if someone turned the key off, and then sometimes has trouble getting back started after this happens. The car typically idles for about 15-30 seconds before this occurs.
We made sure it had gas obviously. It was very low, but this didn't fix the issue. Tried raising the idle screw to be sure the car wasn't just bogging down when the computer shut the IAB valve, set the idle slightly smoother but the random shut off still occurred. Tried changing fuel pump relay just because I happened to have two, no change. I'm thinking this is some electrical gremlin, or something to do with ignition, though the ignition itself seems somewhat new. The car runs amazing when it runs. Revs fine, everything, just turns off suddenly.
So far I'm thinking to check engine grounds, the MAF, (despite it being relatively new) ignition components, maybe clean the salt and pepper shakers, possibly check the ECU for some burnt area. Any other clues as to what can cause such a hard shut off like this?
1990 GT, 5.0, Gt40p heads, upper and lower intake, B cam, BBK Longtubes. Previous owner replaced TONS of little things here and there, new plugs, wires, cap, TFI module, MAF sensor, MAP sensor, TPS, fuel pump, and tons more that are great but not really relevant. It all looks very new, and the engine build itself is relatively new. This was a good deal where the guy mostly just got tired of fooling with it despite heaps of new parts, and hardly touched it from what I can gather (even the engine paint looks good!)
Anyway, here are the symptoms. The car idles good. IAC unplugged, spout unplugged, the car surges a bit but mellows out to the proper 750 RPM or so. Got the TPS dialed in, timing seems normal (don't have a timing light on hand but by feel, it seems fine, and was set previously). With everything plugged in, it idles about 1500 on startup then begins to go down to 1000 or so before it suddenly dies on me.
Only thing is, it randomly just shuts off. no surging, no hunting, just dead stops as if someone turned the key off, and then sometimes has trouble getting back started after this happens. The car typically idles for about 15-30 seconds before this occurs.
We made sure it had gas obviously. It was very low, but this didn't fix the issue. Tried raising the idle screw to be sure the car wasn't just bogging down when the computer shut the IAB valve, set the idle slightly smoother but the random shut off still occurred. Tried changing fuel pump relay just because I happened to have two, no change. I'm thinking this is some electrical gremlin, or something to do with ignition, though the ignition itself seems somewhat new. The car runs amazing when it runs. Revs fine, everything, just turns off suddenly.
So far I'm thinking to check engine grounds, the MAF, (despite it being relatively new) ignition components, maybe clean the salt and pepper shakers, possibly check the ECU for some burnt area. Any other clues as to what can cause such a hard shut off like this?