'91 wont start hot
aging_olds
09-18-2007, 07:48 PM
1991 88Royal 3800 automatic 137k miles
Hi. I don't know how to troubleshoot this and could sure use some help. My son borrowed the car to run to a wedding rehearsal 40 miles away. He stopped once he got there but needed to move the car within a few minutes but it would not start. He called, I arrived with tools to look or to tow two hours later, but it started immediately and without shutting it down drove 40 miles home, no problem. Since then, the car starts and runs fine if cold or not fully warmed up. But if fully warmed up then it won't start until setting about 30 to 45 minutes. The engine turns over but it doesn't seem to be firing. I haven't checked for spark yet when it won't start, but will when I get a chance to run it to fully warm and can shut it down and not be stranded! A parts guy suggested the ignition module at $98 but I'd rather not just guess. Are there some troubleshooting steps to take to the right solution? Really appreciate your help gettin this right the first time.
Hi. I don't know how to troubleshoot this and could sure use some help. My son borrowed the car to run to a wedding rehearsal 40 miles away. He stopped once he got there but needed to move the car within a few minutes but it would not start. He called, I arrived with tools to look or to tow two hours later, but it started immediately and without shutting it down drove 40 miles home, no problem. Since then, the car starts and runs fine if cold or not fully warmed up. But if fully warmed up then it won't start until setting about 30 to 45 minutes. The engine turns over but it doesn't seem to be firing. I haven't checked for spark yet when it won't start, but will when I get a chance to run it to fully warm and can shut it down and not be stranded! A parts guy suggested the ignition module at $98 but I'd rather not just guess. Are there some troubleshooting steps to take to the right solution? Really appreciate your help gettin this right the first time.
maxwedge
09-19-2007, 05:51 AM
Like you said start by checking for spark, if none both the ICM and crank sensor are suspect.
aging_olds
09-22-2007, 07:22 PM
OK. I finally got back to this. Again it started fine cold and after fully warm would not restart. Checked two plugs and no spark at either. Checked codes an only 12 over and over again.
I swithced out the ignition module since it is easy to do. No luck. Is the crank sensor the answer?
I swithced out the ignition module since it is easy to do. No luck. Is the crank sensor the answer?
maxwedge
09-23-2007, 08:24 AM
Usually.
aging_olds
09-23-2007, 11:52 AM
Usually.
Maxwedge -
Knowing there was no spark and I replaced the ICM, is there anything a novice can check to confirm the crankshat position sensor is the problem before replacing it?
thanks for your help!
Maxwedge -
Knowing there was no spark and I replaced the ICM, is there anything a novice can check to confirm the crankshat position sensor is the problem before replacing it?
thanks for your help!
maxwedge
09-23-2007, 04:35 PM
A scanner will look at cranking rpms, if none, usually the sensor is bad.
andropa
09-30-2007, 08:09 AM
had similar problem ...found that there are grounds ganged together and they get warm and cause the car not start till it sits ...found then located drivers side under the carpet in the rail good luck
aging_olds
09-30-2007, 08:50 PM
Hi...I replaced the crankshaft position sensor this weekend and did a long test drive and restart after engine fully hot. Woohoo!!!....appears the problem is solved.
Thanks for the help/advice maxwedge.
For any others that attempt to do this repair on '91 or earlier model, watch for the pin or post in the block that anchors the middle of the pinch-hold pedestal that the sensor sits in. On mine the pin, which I could not see behind the sensor, was slightly corroded and stuck into the old pedestal. It came out of the block with the old pedestal (the new sensor included a new pedestal and pinch bolt). I had to drive the pin out of the old pedestal and hammer it back into the block, and then slightly widen the anchor hole in the new pedestal to get it to slip over the pin.
One other unexpected item -the books say '92 and newer have a dirt cover over the CPS but my '91 also has this cover. It was a bit difficult to get off having never been removed to my knowledge.
andropa-
Thanks, but it was the CPS. Would the ganged ground cause no spark or no fuel? In my case no spark when engine warmed up. I thought I read somewhere that the faulty ganged ground affects the fuel pump?
Thanks for the help/advice maxwedge.
For any others that attempt to do this repair on '91 or earlier model, watch for the pin or post in the block that anchors the middle of the pinch-hold pedestal that the sensor sits in. On mine the pin, which I could not see behind the sensor, was slightly corroded and stuck into the old pedestal. It came out of the block with the old pedestal (the new sensor included a new pedestal and pinch bolt). I had to drive the pin out of the old pedestal and hammer it back into the block, and then slightly widen the anchor hole in the new pedestal to get it to slip over the pin.
One other unexpected item -the books say '92 and newer have a dirt cover over the CPS but my '91 also has this cover. It was a bit difficult to get off having never been removed to my knowledge.
andropa-
Thanks, but it was the CPS. Would the ganged ground cause no spark or no fuel? In my case no spark when engine warmed up. I thought I read somewhere that the faulty ganged ground affects the fuel pump?
Automotive Network, Inc., Copyright ©2024