Intermitent starting problem 90 convertible

[Guest dlane]

A few days ago my Reatta developed an intermitent starting problem. It starts and runs fine when started cold. It will not start and run if the coolant temperature is above approximately 50 degrees Centigrade. There are no diagnostic error messages and all values appear to be normal when I scan through the diagnostic screens. I would appreciate any help or suggestions that will help with the diagnosis and cure. Thanks,

[Guest mongeonman]

I had a similar problem ,a little hard to start when cold and hard to start and sometimes stalling when hot,it was the fuel pump relay,changed it ,no problem since.

[Guest dlane]

I have a slightly different set of symptoms. Mine is not remotely hard to start cold, doesn't stall hot and absolutly will not start hot. It's seems binary, coolant temp above approximately 50 degrees Centigrade won't start, below 50 starts fine. Once started coolant temperature has no impact on the way it runs. It runs fine at the normal operating temp. I've traded relays from one position to another with no change in the problem. Thanks for the suggestion.

[jonlabree]

If you have a 90, the relay is under the CD players position. <img src="http://forums.aaca.org/images/graemlins/grin.gif" alt="" />

[padgett]

A pressure gauge on the fitting on the fuel rail won't lie.

However pure binary sounds more like the Ignition Control Module. Is a complete diagnostics procedure for "cranks but does not run" in the service manual or you can just swap the assembly if you have a spare.

If not try removing the connector, cleaning the contacts, and replacing.

[Barney Eaton]

Based on your two post, it appears the problem is confined to the starter circuit. Here are the possible sources of the problem..in circuit order from the key.

(1) Ignition switch

(2) Starter enable Relay

(2b) Pass key decoder module

(3) Transaxel position switch

(4) starter.

Start with the easy stuff, like the relay, trying the car in Park & Neutral might indicate the transaxel switch (also the transaxel switch should be easy to bypass.

If you suspect the pass key module, you can jumper the termainals at the relay

If all the above are OK that leaves the starter and ignition switch.

Check the mounting bolts on the starter for a good ground and the 12V connection.

[padgett]

Barney's post made me wonder: when you turn the key to start does it just spin without firing or does nothing happen ? We should have started here.

[Guest dlane]

Spins without starting.

[Guest imported_blazer1997]

check fuel pump relay. Make shure it is the correct relay for the pump. Then ck fuel pressure.

[Guest dlane]

The relay is the original. I swapped it for another relay with the same part number. No change in the failure to start problem. It starts and runs fine. Turn it off and it won't start again until the coolant temp is below approximately 50 degrees C. Doesn't seem to matter what the ambient temperature is. Thanks to all for the suggestions. If anyone has any other I'll be happy to try them. Love the car and this is about the second quirky problem I've had. The other was an ECM replacement several years ago.

[Roadster90]

From your description, my money is on the ICM <img src="http://forums.aaca.org/images/graemlins/smile.gif" alt="" />....

(or at least that is what I would start out with) ...

How many miles? When was the last time you had any work on the ignition system?

[padgett]

Next thing- when it won't start, open the hood and then record every engine-related parameter from ED-01 on up. After 10 minutes see if it starts (accessories will cool faster, engine won't.)

[Guest dlane]

I've done this and all readings are within normal range as listed in the service manual. This is how I picked up on the coolant temp variable. When it drops below approximately 50 degrees C it starts. By afternoon, here in Tampa, This takes can take an hour. As to the mileage, the car has just over 100,000 miles on it. Two plus years ago I replaced the "coil" but not IGM. I'll explore this today.

[padgett]

If you were here, we could just try a spare. Ignition module problems seem more age than mileage related though I have yet to have a Delco fail.

[Guest dlane]

When I checked the cable connection earlier today there is a very sticky off-white substance starting to ooze out of the ICM. I purchased an after market replacement this afternoon, GP Sorenson, and will install it after the engine cools off. This particular vehicle uses an ICM manufactured by Magnavox not a standard Delco product. I'll be holding a good thought and see what happens.

[89REATTAJIM]

Didn't realize that you were here in Tampa. Getting ready to leave for vacation this coming Thrs. Will be back following Wed. If I may be of any help after then, let me know.

[Guest dlane]

Thank you for your gracious offer. Have a great trip.

[Guest dlane]

As the expression goes " Houston I've got a problem." I replaced the ICM and now the car won't start at any temperature. Any more suggestions? <img src="http://forums.aaca.org/images/graemlins/confused.gif" alt="" />

[padgett]

First place to look is for a pushed back pin in the ICM connector. Second is for the wires from the coil to the ICM to be on the right blades. Third is for plug wires in the right order.

[Roadster90]

Are you positive you have your/the gang plug seated?

(don't overtighten though)

Are you positive you have the ICM to Coil wiring matched properly?

If your ICM was "Gooing", it was bad or going to be anyway...more than likely is or was the problem...you may have to replace the coil as well....when bending the male tabs (wiring from coil to ICM), did you possibly break or weaken (very easy to do)one?

[Guest dlane]

As my last great act of defiance, I thought I'd try starting the Reatta before going to bed. Now it starts but runs rough. I know the plug wires are on correctly. I know at least three of the leads from the ICM to the coil are correct and I believe the other three are also. I matched the connections from the old unit when I connected the new unit. More diagnostics and checking in the morning. AM check: I removed the coil and rechecked all the terminations, OK. When I reconneced the spark plug wires and started it all was fine. I believe in the advancing twilight last evening I crossed number 3 and 5 hence the rough idle. Once again the car starts and runs very well until I turn it off warm and it won't restart. It occasionally acts as if it might catch but doesn't. This is an improvement but not a fix. It's cooling down and I'm going to check it to see if the restart is at the same temperature as before. I'm beginning to think one symptom may have been masking a second, two problems instead of one.

[2seater]

If it has the correct fuel pressure, for the most part, only the crank sensor and ICM is what starts the engine. If the ICM has been changed, my bet is the crank sensor is temperature sensitive, or there is an intermittant connection. Compressed air or one of those cans of compressed air for electrical dusting would work for a quick check of a specific area.

[Guest alex_houston]

I had a Century that acted like yours. It was the crank sensor cutting out when hot. Rep;laced crank sensor and not a miss since.

[Guest dlane]

Would it run fine hot and when you shut it off it wouldn't start until it was almost cold? The transition point for mine is approximately 50 degrees C. It starts fine up to that temp and will run fine until I shut it off. Then I'm out of business until it cools off. The ICM was apparently in the process of dying. I ran across a tech service bulletin describing the "Gooing" problem and it runs much better with the new ICM. I'll check the crank sensor.

[Guest dlane]

Based on your suggestion I researched the diagnostics in the Service manual and found the exact failure mode I have in the crank position sensor info. Im the process of trying to replace the sensor without removing the harmonic balancer, no luck what a "dumb design", I readjusted the sensor position and it acts differently. Not right but close. So I'm sure it's the sensor. Next question, does anyone know how to replace the sensor without removing the balancer?

[Guest alex_houston]

As far as I know you will be removing the balancer. That is not so bad though. Have fun!

[Guest dlane]

Houston, we have ignition! Replaced the crank position sensor this morning and all is well again. Thanks to all of you for your suggestions, advice and counsel.