Well she is doing it again.. 86 doesn't want to start..
06-03-2011, 11:22 PM
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Well she is doing it again.. 86 doesn't want to start..
I turn the key... I hear the fuel pump build pressure.... I turn the key and it hits like it is going to start and dies... you can still hear the starter spin for a split second, but it doesn't run..
It seems to do it every so often...
Somtimes it will start like a champ on the 1st try.
.Other times it will do as described above.. Then I can let it sit for 10 or 15 minutes and it will fire right up...
It seems to do it every so often...
Somtimes it will start like a champ on the 1st try.
.Other times it will do as described above.. Then I can let it sit for 10 or 15 minutes and it will fire right up...
06-05-2011, 01:44 AM
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Lets start on page 1 of every engine repair manual in the world. Engines need hot spark, spark at the right time, fuel and air and compression in order to start and continue to run. The time to start your diagnostics is when it won't start. Use your timing light to see if you have spark and spark at the right time. Later C4's don't have a timing mark on the crank pulley ( it would help if you posted the year Corvette you are asking help for). Measure the fuel pressure at the shraeder valve at the end of the right side fuel rail, it should be 35-42 psi. Use a noid light (available at parts stores) to see if the injectors are being pulsed during cranking. Spray starting fluid into the intake and see if it starts and runs for a short time. If it does, you are not getting fuel into the engine. Since your car does start and run sometimes, I doubt you have low or no compression, but checking it eliminates that as a cause.
06-05-2011, 08:09 AM
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Lets start on page 1 of every engine repair manual in the world. Engines need hot spark, spark at the right time, fuel and air and compression in order to start and continue to run. The time to start your diagnostics is when it won't start. Use your timing light to see if you have spark and spark at the right time. Later C4's don't have a timing mark on the crank pulley ( it would help if you posted the year Corvette you are asking help for). Measure the fuel pressure at the shraeder valve at the end of the right side fuel rail, it should be 35-42 psi. Use a noid light (available at parts stores) to see if the injectors are being pulsed during cranking. Spray starting fluid into the intake and see if it starts and runs for a short time. If it does, you are not getting fuel into the engine. Since your car does start and run sometimes, I doubt you have low or no compression, but checking it eliminates that as a cause.
The servce enfine light is flashing "46" which is the Vats system... The weird thing is that it still turns over..plus it started up and ran last night even with Vats code stored... I know I have had issue with my TPS not being set correctly..That may be my issue also...
Will an engine still crank still crank if the Vats system is activated? I know the injectors won't allow the motor to run, but I didn't think it would event crank once the Vats was activated..
06-05-2011, 10:47 AM
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If the VATS module does not detect the correct ign key pellet resistance (must be within 4%) it will not close the start enable relay and 12v will not make it to the starter solenoid and you will hear silence. Your ECM can store a previous VATS failure and continue to store and display it even though it is working now.
06-05-2011, 10:58 AM
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If the VATS module does not detect the correct ign key pellet resistance (must be within 4%) it will not close the start enable relay and 12v will not make it to the starter solenoid and you will hear silence. Your ECM can store a previous VATS failure and continue to store and display it even though it is working now.
It still has a really high idle though, I am starting to notice there is a process to starting it (crazy as that sounds)...... I am also starting to wondering I if I have clogged injectors form it sitting so long.. I will try to test the pressure as suggestion once I get a chance & figure out exactly how to do it.. Thanks again..
06-05-2011, 12:05 PM
#7
Burning Brakes
I had weird starting issues with my '86 years ago, thought it was my starter solenoid acting up again. Turned out to be the VATS. The contacts in the key cylinder are notorious for not connecting to the key resistor. I purchased a new key switch (re-used the old tumblers = same key). When I pulled the steering column all apart to get to the switch one, of the contact wires literally fell off in my hand. 
Made me wonder how it ever started at all.
Made me wonder how it ever started at all.
06-05-2011, 06:21 PM
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I had weird starting issues with my '86 years ago, thought it was my starter solenoid acting up again. Turned out to be the VATS. The contacts in the key cylinder are notorious for not connecting to the key resistor. I purchased a new key switch (re-used the old tumblers = same key). When I pulled the steering column all apart to get to the switch one, of the contact wires literally fell off in my hand. Made me wonder how it ever started at all.
Made me wonder how it ever started at all.
06-05-2011, 06:33 PM
#9
Le Mans Master
My 86 used to have an extended high idle every time i started it....I got tired of that and put in an 87 chip. Now the high idle is just for a few seconds. Much more enjoyable.
When it had the extended start problem, the pulsator in the tank was the problem. I never had the vats indication you are getting.
Now with the 383, sometimes you have to try it 3 times, and use the gas pedal on the middle try.
When it had the extended start problem, the pulsator in the tank was the problem. I never had the vats indication you are getting.
Now with the 383, sometimes you have to try it 3 times, and use the gas pedal on the middle try.
06-05-2011, 09:41 PM
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My 86 used to have an extended high idle every time i started it....I got tired of that and put in an 87 chip. Now the high idle is just for a few seconds. Much more enjoyable.
When it had the extended start problem, the pulsator in the tank was the problem. I never had the vats indication you are getting.
Now with the 383, sometimes you have to try it 3 times, and use the gas pedal on the middle try.
When it had the extended start problem, the pulsator in the tank was the problem. I never had the vats indication you are getting.
Now with the 383, sometimes you have to try it 3 times, and use the gas pedal on the middle try.
The high idle does drive me crazy.. The idle even makes the car shift harder when putting into gear our of park,,,
