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3.4L DOHC, runs fine, then on occasion won't start
Ok here is the deal. I have a 92 Oldsmobile Cutlass Supreme with a 97 3.4L LQ1 crate motor in it. Put the new motor in about 6 years ago and 50k on it.
I was driving last monday, and it hesitated a couple of times as I accelerated across a road and then about 5 seconds later died. I couldn't get it restarted, it seemed like it was spinning the motor but no signs of life. While waiting for the tow truck, I managed to get it started after swapping out the ICM & coil packs (I have an extra, it used to be a problem in this car), checking all the fuses, swaping the relays between the fans and ECM etc. Seemed to me like it just decided to start after 30 or 40 minutes. Drove it back to work, then drove it home that night. I took the ICM and coils to autozone, and they declared the icm bad, and the coils good. And I thought good, that is that.
Tuesday was meet the teacher night, and after driving to work, and then about 15 minutes over to a Wendy's before the MT night. When I went to leave at 8:30.. no go.. Cranked wierd like it was trying to fire, but sometimes more like a mis-fire. Swapped ICM and Coils.. nothing but spinning. Called my wife and she drove me home, and dropped me off early the next day and I played with it... put the ICM and coils that were on it back.. just cranked. Checked to see if there was fuel, sprayed it all over. Checked the fuses and the wires at the ICM.. looked good. Then once again it started. Went in cleaned up, taught all day, drove it to a shop near my house.
They looked at it Wed, Thurs, Fri and supposedly called me late friday to say that they thought it was something in the wiring harness causing a mis-fire, but they also said that from camshaft sensor should be hooked up. The 92 has 1, the 96-97 two becuase it is OBDII. I still have the original computer, so I don't use that sensor. So I go late Saturday morning over there, my wife drops me off and I go out to the car and it won't start. Supposedly it hadn't started since I dropped it. Work on it for about 2 hours, checked the wires on the ICM (can't really see much of the one from the CKP), checked the wires out of the computer and fuse area. Later I bought a new Volt meter (my old one was malfunctioning), saw the right power to the ICM, signal from the CKP, but also did an ohm test on the CKP and it read 984, and was supposed to be between 300-900. Charged the car battery, becuase it didn't want to spin well... after about 10 or 12 cranks it fired off and stalled, a couple more times and it ran... threw the tools in the car and van and drove it home.
Sunday I tried to replace the CKP, and just don't have a long enough 10mm to get in there with my big hand. My pastor suggested his mechanic so I drove it over this morning (Mon). 3 times while driving it sputtered: turning right and accelerating medium light, from a stop light in 1st gear, and getting ready to accelerate from a turn onto the feeder onto the freeway (which was a right but the turn was completed). It would hesitiate like there was 0 power then catch.
Mechanic replaced the CKP, started and ran great. Then on another test drive this afternoon, the mechanic drove down to the local gas station/convience store, and it wouldn't restart, sounded like it was mis-firing when it tried to start.
What can this be? Shorted wires? if so why does it run well sometimes and then completely not start, and no blown fuses? 24x sensor? I was reading on line that it couldn't cause a no-start, but just running bad. I was reminded by a friend that it can't be a Camshaft position sensor.. it isn't hooked up in OBD, and nothing has been connected to it.
Ideas? Thanks for your help
I was driving last monday, and it hesitated a couple of times as I accelerated across a road and then about 5 seconds later died. I couldn't get it restarted, it seemed like it was spinning the motor but no signs of life. While waiting for the tow truck, I managed to get it started after swapping out the ICM & coil packs (I have an extra, it used to be a problem in this car), checking all the fuses, swaping the relays between the fans and ECM etc. Seemed to me like it just decided to start after 30 or 40 minutes. Drove it back to work, then drove it home that night. I took the ICM and coils to autozone, and they declared the icm bad, and the coils good. And I thought good, that is that.
Tuesday was meet the teacher night, and after driving to work, and then about 15 minutes over to a Wendy's before the MT night. When I went to leave at 8:30.. no go.. Cranked wierd like it was trying to fire, but sometimes more like a mis-fire. Swapped ICM and Coils.. nothing but spinning. Called my wife and she drove me home, and dropped me off early the next day and I played with it... put the ICM and coils that were on it back.. just cranked. Checked to see if there was fuel, sprayed it all over. Checked the fuses and the wires at the ICM.. looked good. Then once again it started. Went in cleaned up, taught all day, drove it to a shop near my house.
They looked at it Wed, Thurs, Fri and supposedly called me late friday to say that they thought it was something in the wiring harness causing a mis-fire, but they also said that from camshaft sensor should be hooked up. The 92 has 1, the 96-97 two becuase it is OBDII. I still have the original computer, so I don't use that sensor. So I go late Saturday morning over there, my wife drops me off and I go out to the car and it won't start. Supposedly it hadn't started since I dropped it. Work on it for about 2 hours, checked the wires on the ICM (can't really see much of the one from the CKP), checked the wires out of the computer and fuse area. Later I bought a new Volt meter (my old one was malfunctioning), saw the right power to the ICM, signal from the CKP, but also did an ohm test on the CKP and it read 984, and was supposed to be between 300-900. Charged the car battery, becuase it didn't want to spin well... after about 10 or 12 cranks it fired off and stalled, a couple more times and it ran... threw the tools in the car and van and drove it home.
Sunday I tried to replace the CKP, and just don't have a long enough 10mm to get in there with my big hand. My pastor suggested his mechanic so I drove it over this morning (Mon). 3 times while driving it sputtered: turning right and accelerating medium light, from a stop light in 1st gear, and getting ready to accelerate from a turn onto the feeder onto the freeway (which was a right but the turn was completed). It would hesitiate like there was 0 power then catch.
Mechanic replaced the CKP, started and ran great. Then on another test drive this afternoon, the mechanic drove down to the local gas station/convience store, and it wouldn't restart, sounded like it was mis-firing when it tried to start.
What can this be? Shorted wires? if so why does it run well sometimes and then completely not start, and no blown fuses? 24x sensor? I was reading on line that it couldn't cause a no-start, but just running bad. I was reminded by a friend that it can't be a Camshaft position sensor.. it isn't hooked up in OBD, and nothing has been connected to it.
Ideas? Thanks for your help
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