A 1991 5.0 with manual trans, 127,000, and bone stock besides header back exhaust and tune up. For some time now I haven't been able to rev above 4500 rpm, and when I do go that high it sounds like the engine hits a brick wall. After a good 15,000 miles of this problem I am ready to dive in and fix this. Here are some things that might help. When I play the radio, I get noise from the the plug wires, because the CD player part works without noise. I have checked and double check igintion timing and tried both advancing and retarding it. I have taken the TFI out and put it all back together with di-electric grease. New fuel pump, filter and I have constant fuel pressure. Cap, rotor, coil are new. No cats, so there not clogged, and the motor runs well beisdes this one problem. I thought maybe the I had valve float, a weak igintion or a faulty computer. ?????? any ideas ?????? I can't figure it out, non of my buddies have a clue.
Will not rev up
- Thread starter Cheap91GT
- Start date
onefstsnake
New Member
check all your grounds, Coil could be dying, Check the codes...
Ohm the injectors...
Could be alot of things.
Ohm the injectors...
Could be alot of things.
a long long time ago i was working on a 92 5.0 that did this. it turned out to be the PCM. water was leaking from the windsheild and the water was going right intot he kick panel where the pcm is.
In addition, we have to ask: you dont run platinum plugs do ya?
Issues like that can be hard to track down since items will bench test fine (TFI, etc) but they are just not cutting it in a hot, high-load dynamic.
If you have a bud with a stang, perhaps you can swap the TFI and coil and see if the issue abates.
Good luck.
Issues like that can be hard to track down since items will bench test fine (TFI, etc) but they are just not cutting it in a hot, high-load dynamic.
If you have a bud with a stang, perhaps you can swap the TFI and coil and see if the issue abates.
Good luck.
joel5.0
Member
You might want to start by doing a round of KOEO/KOER self-tests and checking the condition of the stator sensor in the dizzy. Your observation regarding the electrical noise might be the clue in solving the problem, it may be affecting the PIP signal. Also check the noise filter capacitor at the coil. My 2¢.
I have checked all codes with engine on, engine off, and came up with only emissions purge codes. Because I removed the thermactor. I have had problems with platinum plugs with my pervious stang and I made sure to run coppers in this one. I like the PIP idea, since I've been leaning towards a bad electrical componet.
Although I have never heard of the noise filter capacitor. Where is the location of this, what does it look like, and where might I go to get a new one.??
Thanks guys you've given me new hope for this problem.
Although I have never heard of the noise filter capacitor. Where is the location of this, what does it look like, and where might I go to get a new one.??
Thanks guys you've given me new hope for this problem.
Zero_chance
Founding Member
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