Need help with 302 ignition system
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Joined: Sep 2001
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Need help with 302 ignition system
Hello all,
This is really not a truck help request, but your help is greatly appreciated.
Have a Crown Vic with a 302 that has the following simptoms:
1) When holding steady speeds between 35-45MPh gets jerky engine operation like it for a fraction of a sec cuts electrical signals to spark plugs off. Which makes it gitter/jerk like a gitter bug.
2) No output can be received from CPU (CPU replaced with same results) so have no idea how to get any intelligent info out......
Many suggestions from friends and professional alike 1) Try another CPU 2) TPS 3) Intermittent connector (Lord forbid there are hundreds of them)
Any ideas/help is greatly apreciated.
Adriano
This is really not a truck help request, but your help is greatly appreciated.
Have a Crown Vic with a 302 that has the following simptoms:
1) When holding steady speeds between 35-45MPh gets jerky engine operation like it for a fraction of a sec cuts electrical signals to spark plugs off. Which makes it gitter/jerk like a gitter bug.
2) No output can be received from CPU (CPU replaced with same results) so have no idea how to get any intelligent info out......
Many suggestions from friends and professional alike 1) Try another CPU 2) TPS 3) Intermittent connector (Lord forbid there are hundreds of them)
Any ideas/help is greatly apreciated.
Adriano
FTE Chapter Leader
Joined: Sep 2000
Posts: 3,863
Likes: 5
From: Beachville, Ontario
Need help with 302 ignition system
Try unplugging the EGR valve and go for a drive. Sometimes as these things go, they open too early and go open-shut constantly causing the vehicle to buck.
If you have the same bucking problem under max acceleration or at high speeds it could be your spark plug wires.
1979 F150 Custom: 84 351W: 91 heads, Crane PowerMax cam, double roller timing chain, Edelbrock Performer intake & Edelbrock carb
1987 F150 XLT Lariat: 88 351W EFI
86 & 87 Bronco II: next winter's beater
If you have the same bucking problem under max acceleration or at high speeds it could be your spark plug wires.
1979 F150 Custom: 84 351W: 91 heads, Crane PowerMax cam, double roller timing chain, Edelbrock Performer intake & Edelbrock carb
1987 F150 XLT Lariat: 88 351W EFI
86 & 87 Bronco II: next winter's beater
Thread Starter
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New User
Joined: Sep 2001
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Need help with 302 ignition system
Well tried the TPS first, no change. I then tried the EGR......unplugged it and at first it appeared to lessen the jerking tremendowsly, but then it really started missing first at higher speeds (45-55) but now one to three cilinders drop-out as soon as gas is given while in gear.
Any more ideas?
1979 400CID Bronco
1978 300CID F100
Any more ideas?
1979 400CID Bronco
1978 300CID F100
FTE Chapter Leader
Joined: Sep 2000
Posts: 3,863
Likes: 5
From: Beachville, Ontario
Need help with 302 ignition system
Check the ignition module or the coil. Sometimes it's handy to have spares of these sitting around to investigate that kind of problem.
1979 F150 Custom: 84 351W: 91 heads, Crane PowerMax cam, double roller timing chain, Edelbrock Performer intake & Edelbrock carb
1987 F150 XLT Lariat: 88 351W EFI
86 & 87 Bronco II: next winter's beater
1979 F150 Custom: 84 351W: 91 heads, Crane PowerMax cam, double roller timing chain, Edelbrock Performer intake & Edelbrock carb
1987 F150 XLT Lariat: 88 351W EFI
86 & 87 Bronco II: next winter's beater
