Intermitten hard start
#1
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Intermitten hard start
I've got a 94 LT1 Auto. Over the last 3 months, I've starting having an occasional hard start. It turns over just fine, but, won't start. At first it took 3 or 4 tries to start-but, it did start. A month later, same thing, no start, unless I came off the start position to run real quick. Usually, I just tap the start position on the key switch it starts just fine. Both times, it would not start until I came back to the Run position. This week, it wouldn't start at all for 5 or 7 tries, then just fired up fine.
I checked the fuel pressure, 40-45 lbs, and the fuel pump shuts off. Maintians about 40 lbs running, holds 40 lbs for over 30 minutes after shutoff.
Ran Datamaster, got the EGR flag as usual, also got a "MALF 29-EAS elec fault". What the heck is that. I can't find that in my manual and I've looked for a listing of the codes on here. I know CasetheCorvetteMan has posted them several times, I haven't been able to find them.
Anyway, this is a intermittent problem. I wanna take a little road trip but not with this hanging over my head. Any ideas?
I checked the fuel pressure, 40-45 lbs, and the fuel pump shuts off. Maintians about 40 lbs running, holds 40 lbs for over 30 minutes after shutoff.
Ran Datamaster, got the EGR flag as usual, also got a "MALF 29-EAS elec fault". What the heck is that. I can't find that in my manual and I've looked for a listing of the codes on here. I know CasetheCorvetteMan has posted them several times, I haven't been able to find them.
Anyway, this is a intermittent problem. I wanna take a little road trip but not with this hanging over my head. Any ideas?
#3
Burning Brakes
I know you said you measured the fuel pressure while running and after you turned it off, but did you measure it while cranking? If it's a relay problem, it may be the fuel pump relay.
After you crank it and it doesn't start, smell the exhaust. If it smells like straight fuel then you are getting gas, but no spark.
Do you hear or feel any "bumping" when your turning it over? It may be something wrong with your distributor causing late/misfires at start-up.
One thing that comes to mind with the distributor is bad contact points. You might not be getting enough juice during cranking to arc across burnt points, but when the alt kicks in it might. Would that mean a bad battery as well? This is just something that popped into my head. I have to look at how the wiring is set up.
After you crank it and it doesn't start, smell the exhaust. If it smells like straight fuel then you are getting gas, but no spark.
Do you hear or feel any "bumping" when your turning it over? It may be something wrong with your distributor causing late/misfires at start-up.
One thing that comes to mind with the distributor is bad contact points. You might not be getting enough juice during cranking to arc across burnt points, but when the alt kicks in it might. Would that mean a bad battery as well? This is just something that popped into my head. I have to look at how the wiring is set up.
#4
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Similar no start trouble.
I had a no start problem and it turned out to be a crack in the COIL that arced to the coil bracket while trying to starting the engine. See my post today for trouble finding the problem. ART
#5
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I know you said you measured the fuel pressure while running and after you turned it off, but did you measure it while cranking? If it's a relay problem, it may be the fuel pump relay.
After you crank it and it doesn't start, smell the exhaust. If it smells like straight fuel then you are getting gas, but no spark.
Do you hear or feel any "bumping" when your turning it over? It may be something wrong with your distributor causing late/misfires at start-up.
One thing that comes to mind with the distributor is bad contact points. You might not be getting enough juice during cranking to arc across burnt points, but when the alt kicks in it might. Would that mean a bad battery as well? This is just something that popped into my head. I have to look at how the wiring is set up.
After you crank it and it doesn't start, smell the exhaust. If it smells like straight fuel then you are getting gas, but no spark.
Do you hear or feel any "bumping" when your turning it over? It may be something wrong with your distributor causing late/misfires at start-up.
One thing that comes to mind with the distributor is bad contact points. You might not be getting enough juice during cranking to arc across burnt points, but when the alt kicks in it might. Would that mean a bad battery as well? This is just something that popped into my head. I have to look at how the wiring is set up.
#6
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When it won't start immediately, THAT is the time to do some diagnostics. Engines need spark, fuel, air , and compression in order to start and continue to run. Pull a spark plug wire and bring a grounded wire close to the inside of the plug boot while someone cranks for a short time. You should see a snappy at least 1/2" spark.
That you can go back to run and get it to start is an indication that you have a worn ignition switch.
That you can go back to run and get it to start is an indication that you have a worn ignition switch.
#8
no start, unless I came off the start position to run real quick. Usually, I just tap the start position on the key switch it starts just fine. Both times, it would not start until I came back to the Run position. This week, it wouldn't start at all for 5 or 7 tries, then just fired up fine.
Personally, I would replace the switch and see if that fixes it.
I have not replaced a C4 switch, but in older (70's 80's) GM's it was usually located under the dash on top of(or on the side of) the steering column.
Also, the older switches did not just "bolt" in place, they were actually adjustable and had to be positioned and tightened in place. 1 in a 1,000,000 chance it could have shifted, but I doubt it.
I do know that when I disassembled switches to analyze failures in the the past, it was typically the start that failed and it failed because the switch was maladjusted so that the start contacts were barely touching and over time it blew the contacts apart.
#10
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118000 miles, I've replaced the opti (MSD) about 4 years ago and did plugs and wires and ing. module at the same time. It runs good and gets fine gas mileage (as long as I stay off crappy ethanol gas).
I realize it's hard to fix a sometimes problem. The error code was a real stumper for me. I still haven't found what it is.
I realize it's hard to fix a sometimes problem. The error code was a real stumper for me. I still haven't found what it is.
#11
i only drive my 89 once in a while.it sets a week or two at a time. cranks just fine but wont start. after getting the battery fully charged up up i started useing a battery tender so my alarm didnt drain the battery.i now it starts instantly.i started it tonight and it fired so fast i was shocked. i think it needs a real full charge.