L98's a no starter - even with "plug" fix
03-24-2014, 11:35 AM
#1
Intermediate
Thread Starter
L98's a no starter - even with "plug" fix
Hi there.
I did a rebuild on a '90 L98 350.
It’s been running very fine for 6 months. Lately I however picked up a very strange problem. A week or so ago it would not start. You could hear the fuel injection start up when you turn the ignition switch and the motor would crank, but it would not start. I tried several times.
In desperation I unplugged the plug wire from cylinder 3. Cranked it again and it worked! Strange!!!
I switched off, plugged the wire back in and started it again – it started without any problem.
The next week it started without any problems.
THEN, again it had the same problem. I tried the “plug trick”, but it did not work. Eventually I disconnected the battery for 10 seconds and THAT worked.
Another week it starts without any problems.
This afternoon I tried to start it again, and same starting problem happens. Now no amount of disconnecting battery or unplugging spark plug works at all.
Anybody have ANY idea what’s happening?
Thank you.
Henk
I did a rebuild on a '90 L98 350.
It’s been running very fine for 6 months. Lately I however picked up a very strange problem. A week or so ago it would not start. You could hear the fuel injection start up when you turn the ignition switch and the motor would crank, but it would not start. I tried several times.
In desperation I unplugged the plug wire from cylinder 3. Cranked it again and it worked! Strange!!!
I switched off, plugged the wire back in and started it again – it started without any problem.
The next week it started without any problems.
THEN, again it had the same problem. I tried the “plug trick”, but it did not work. Eventually I disconnected the battery for 10 seconds and THAT worked.
Another week it starts without any problems.
This afternoon I tried to start it again, and same starting problem happens. Now no amount of disconnecting battery or unplugging spark plug works at all.
Anybody have ANY idea what’s happening?
Thank you.
Henk
03-24-2014, 11:55 AM
#2
Well,
when its cranks (engine turning over with the starter) but does not start and run......
does it have spark at the plugs?
does it have fuel pressure? if so, how much?
To be clear, the starter motor runs, it turns the engine over as it should, but the engine does not fire and run? correct?
IF that is accurate, then I would go to the dist cap and check ALL the wires to the cap/coil/ and ICM inside the dist.
A lose wire on the cap will cause intermittent starting problems.
Also, look at all the hot wires from behind and under the battery. There are fusible links under the battery box that can cause problems. These supply power to the ECM and EFI on the engine.
Got a NOID lite? You need one. IF the fuel injection pump IS running, and you ARE getting 40 psi at the rails, AND there is spark and the starter motor is turning the engine over but it will NOT start, you now need to confirm that the injectors are cycling. A NOID lite tells you they are working.
IF the inj are NOT working, none, then you have t o look at the VATS module that has the EFI lock-out as part of the anti-theft protection. If the VATS module fails, it stops the inj from working. This SHOULD also stop the starter, UNLESS the starter has been bypassed or the enable relay has been jumped.
I know this is confusing but this is a complex system. Far ahead of its time. You MUST discover whats doing its job and when. Many things are not supposed to be running...and some are.
Your FSM should help with that.
Fuel pressure, NOID lite, spark tester.
See what those things tell you and go from there.
Good luck
when its cranks (engine turning over with the starter) but does not start and run......
does it have spark at the plugs?
does it have fuel pressure? if so, how much?
To be clear, the starter motor runs, it turns the engine over as it should, but the engine does not fire and run? correct?
IF that is accurate, then I would go to the dist cap and check ALL the wires to the cap/coil/ and ICM inside the dist.
A lose wire on the cap will cause intermittent starting problems.
Also, look at all the hot wires from behind and under the battery. There are fusible links under the battery box that can cause problems. These supply power to the ECM and EFI on the engine.
Got a NOID lite? You need one. IF the fuel injection pump IS running, and you ARE getting 40 psi at the rails, AND there is spark and the starter motor is turning the engine over but it will NOT start, you now need to confirm that the injectors are cycling. A NOID lite tells you they are working.
IF the inj are NOT working, none, then you have t o look at the VATS module that has the EFI lock-out as part of the anti-theft protection. If the VATS module fails, it stops the inj from working. This SHOULD also stop the starter, UNLESS the starter has been bypassed or the enable relay has been jumped.
I know this is confusing but this is a complex system. Far ahead of its time. You MUST discover whats doing its job and when. Many things are not supposed to be running...and some are.
Your FSM should help with that.
Fuel pressure, NOID lite, spark tester.
See what those things tell you and go from there.
Good luck
