- Apr 4, 2007
- 168
- 62
- 38
I have a 93 LX with a 306, S-Trim, Trick LFow heads, cobra intake, MSD ignition box with boost retard control. I replaced the computer about two months before this began, it was running like a champ too.
Here is the problem. One day I drove it for about two hours when all of a sudden it began to backfire and sputter at 60 mph. As i gave it gas it just backfired very loud and had no power, it would just stumble and backfire as I slowed down due to no acceleration. I coasted into a parking lot and cut it off. I looked for a burned plug wire but didn't find one. started about 15 min later and it just stumbled like to timing was way off. It would not rev at all just back fire when I pushed the gas pedal down. A couple more times and then it would not start at all. I tried to start it several times and I smelled the faint odor of fuel... I towed it home where it sits.
I replaced the coil, cap, rotor, plug wires, ignition module, ignition switch, EEC relay. The fuel gauge reads about 38 psi when i turn the key on, i hear the fuel pump prime and cut off too. I pulled a plug (plug looked fine) and grounded the plug as the wife turned the ignition, no spark. I tested the MSD box using MSD's directions (ground white wire or something to that effect from box) and it shows good (nice blue spark at the test point).
The problem seems obvious, no spark. If the MSD box is good then the next step is the coil but it is a brand new MSD unit i bought two days ago (i thought this was the problem but no luck). Also the "hot" wire from the msd to the coil had the inline fuse melted so i replaced this section of wire (about 4 inches). Where should I go next? Should I replace all of the wire that was inline with the melted fuse (no other signs of melting to the insulation) or is this a long shot. Please help I've about had it!!
BTW I'm no mechanic so layman terms would help
Here is the problem. One day I drove it for about two hours when all of a sudden it began to backfire and sputter at 60 mph. As i gave it gas it just backfired very loud and had no power, it would just stumble and backfire as I slowed down due to no acceleration. I coasted into a parking lot and cut it off. I looked for a burned plug wire but didn't find one. started about 15 min later and it just stumbled like to timing was way off. It would not rev at all just back fire when I pushed the gas pedal down. A couple more times and then it would not start at all. I tried to start it several times and I smelled the faint odor of fuel... I towed it home where it sits.
I replaced the coil, cap, rotor, plug wires, ignition module, ignition switch, EEC relay. The fuel gauge reads about 38 psi when i turn the key on, i hear the fuel pump prime and cut off too. I pulled a plug (plug looked fine) and grounded the plug as the wife turned the ignition, no spark. I tested the MSD box using MSD's directions (ground white wire or something to that effect from box) and it shows good (nice blue spark at the test point).
The problem seems obvious, no spark. If the MSD box is good then the next step is the coil but it is a brand new MSD unit i bought two days ago (i thought this was the problem but no luck). Also the "hot" wire from the msd to the coil had the inline fuse melted so i replaced this section of wire (about 4 inches). Where should I go next? Should I replace all of the wire that was inline with the melted fuse (no other signs of melting to the insulation) or is this a long shot. Please help I've about had it!!
BTW I'm no mechanic so layman terms would help