won't restart until engine cools down

[Craig]

Hello. I have an 89' SHO since 1990. Its in pretty good shape in and out and starts and runs good. Its has 150K miles. My problem is that after the engine warms up and I turn the engine off, it won't restart until the engine cools down. The refractory period shortens as the outside temperature gets colder. I'm leaning toward the DIS module, but I'm not a mechanic. Any help is appreciated. Thanks. Craig in Kentucky

 

[rubydist]

Every time I had this happen, it was leaking injectors that would flood the engine when hot. Next time you try a hot restart, hold the gas pedal all the way to the floor and see if it starts. If so, its flooded, and most likely from a leaking injector.

 

[Craig]

Every time I had this happen, it was leaking injectors that would flood the engine when hot. Next time you try a hot restart, hold the gas pedal all the way to the floor and see if it starts. If so, its flooded, and most likely from a leaking injector.

When the engine gets hot, the car will not turn over. I can hear the fuel pump. And then when it cools down (temperature gauge in cold range), it cranks right up. I will try what you suggest, but I'm thinking maybe you thought the car was cranking but not starting? Thanks.

 

[sperold]

Try tapping the solenoid on the driver's side fender, and wiggle that small wire on the solenoid that triggers the connection of battery power to the starter motor.

It is a long shot, but it is an odd situation.

Other than that, have a look at your starter motor, strange things can happen inside it as well.

I presume you have already checked your water pump weep hole for a leak that can soak your shutter wheel and interfere with the crank position sensor reading.

 

[Craig]

I'll have your suggestions looked at. And I have replaced the water pump and crank sensor about a year and a half ago for the reason you point out. I hope its still OK. I'll ask the mechanic to revisit that. Thanks.

 

[SHOCH]

My money on crank sensor.

 

[Craig]

My money on crank sensor.

You think maybe the sensor has gone out again? I'll run diagnostics again. There is an error code for that I think.
When I have had crank or cam shaft sensor problems in the past, they caused the engine to behave in strange ways. Thanks.

 

[SHOCH]

Mine did that and that fixed it.

 

[sperold]

I am not sure there is a code for the crank sensor. It may be reported as something associated with timing or something even more obscure, but I don't think there is a direct call-out.

There is a code for the cam sensor.

 

[zoomlater]

code 211 is the crank sensor code. I had this code pop up when my water pump was leaking on it. I read not all cars will throw this code when the sensor is failing

Did you replace your crank sensor with a brand new unit or was it used

 

[rubydist]

the crank sensor will not prevent the engine from cranking over with the starter. that would be unrelated to this issue.

I have had starter solenoids that (when hot) would not engage, and would work again when they cooled. I think sperold is on the right track here. there also could be a bad connection issue between the battery and the starter motor.

 

[Craig]

the crank sensor will not prevent the engine from cranking over with the starter. that would be unrelated to this issue.

I have had starter solenoids that (when hot) would not engage, and would work again when they cooled. I think sperold is on the right track here. there also could be a bad connection issue between the battery and the starter motor.

When the water pump leak was found, a new water pump and crank sensor were put in. And battery and starter are less than a year old. When it cranks, it starts right up.

I do have an error code 19 which is the cam shaft position sensor. I did have it replaced before. I asked him to make sure there was no oil in the sensor. He said there was not, but when I examined the old sensor there was a wisp of oil in a very definite long rectangular pattern.

I'm not having any behavioral issues like I've had when that sensor has gone out in the past. I think the 19 error and this car not starting until it cools down issue are 2 different things. What do you all think??? I'll look at that starter solenoid. Thanks everyone.

 

[Craig]

When the water pump leak was found, a new water pump and crank sensor were put in. And battery and starter are less than a year old. When it cranks, it starts right up.

I do have an error code 19 which is the cam shaft position sensor. I did have it replaced before. I asked him to make sure there was no oil in the sensor. He said there was not, but when I examined the old sensor there was a wisp of oil in a very definite long rectangular pattern.

I'm not having any behavioral issues like I've had when that sensor has gone out in the past. I think the 19 error and this car not starting until it cools down issue are 2 different things. What do you all think??? I'll look at that starter solenoid. Thanks everyone.

I have a Gen1 diagnostic computer and that 19 was after the KOEO 11 (all actuators and relays are OK) and 10 (separator code). It was a continuous memory code. I don't know if the tests run for the 11 included the starter solenoid.

 

[Craig]

Fou

I have a Gen1 diagnostic computer and that 19 was after the KOEO 11 (all actuators and relays are OK) and 10 (separator code). It was a continuous memory code. I don't know if the tests run for the 11 included the starter solenoid.

Found another interesting thing. I was looking at the DIS module when I ran diagnostics. It only has 3 screws in it and those 3 were loose. It may have vibrated out. I don't work on my car unless its something easy. The missing screw is the bottom left one. The engine manual I have says that 'PIN 7 (IGN GND) IS CONNECTED INTERNALLY TO THE BOTTOM DIS MODULE MOUNTING HOLES'. Is this missing screw a problem. I'm thinking the mechanic should have brought this to my attention.

 

[zoomlater]

yes, some of them are grounds so they need to be secure

 

[luigisho]

If you have issues related to heat make sure there is a good coating of thermal paste in the middle of the back of the DIS where heat transfer can occur from the intake manifold. If it's old paste replace only in the area of the old stuff.

 

[rubydist]

Those are all legit concerns, but none of them will prevent the engine from turning over with the starter.

There is no code in the pcm for a starter solenoid - the pcm has no way to know if the solenoid is working or not.

The no-crank issue when hot is related to either the starter motor, the starter solenoid, or the wiring from the battery to the solenoid to the starter. Those are really the only items in play as to whether the engine cranks over, other than the key switch and the clutch interlock switch.

 

[blk\blk90]

I doubt it's the cam sensor. When mine went bad it would start everytime when cold, but when hot it would take a few times. But it would crank everytime.

 

[SHOrod]

To reiterate what Rubydist has stated a couple of times above, if the starter is not attempting to spin the engine over (as the original poster has stated now), the issue will have nothing to do with a sensor (Crank, Cam, you name it) or the DIS module. The focus here should be on the starting system and components from the battery to the starter.

Since the issue only appears when the engine is hot, that suggests to me it's most likely as issue with the starter motor assembly (starter motor and/or solenoid). Something is going open circuit when hot, or expanding and sticking causing an open circuit. You could try tapping on the starter motor with a broom handle or similar when failing and if that enables it to work, replacing the starter motor assembly should fix your issue. Don't assume that just because the starter was replaced recently it cannot be the issue. It's probably a rebuilt starter and I doubt they test them at high temperatures when testing following the rebuild.

-Rod

 

[Craig]

Thanks again for all the responses everyone. ct