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1990 Reatta hard start when warm or hot.


Guest loupet

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Guest loupet

Hello out there. My name is Lou and I`m a newbe here so, please bare with me. I just bought a 1990 reatta convertible any starting to learn about this car. My issue is the car starts right up when cold but, has a hard time starting when warm or hot. I replace the ignition coil and module (original was melted and got all over the harness plug that plugs into the module) plugs, wires, and crank shaft sensor. Hope someone can help and steer me in the right direction.  thanks to you all.  Lou

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I remember from a previous post that you replaced the fuel pump but you may want to check the fuel presure. I would also check out the fuel pump relay [I believe on the 1990 it was moved to the drivers side fuse box]. The fuel preesure test is a simple procedure and the relay is cheap [less then $10.00].

 If you want something to give you a quick start go to Ronnie's website [Reatta owner journal] and check out the tutorials listed there. It's pretty much a layman's "How to" for a lot of repairs. It is a good place to start...

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One other possibility is the starter. I have had three GM vehicles (two Cadillacs

 and one Reatta so far) exhibit this when the starter is at end of life. Will start normally at cold engine, but when hot will be very slow to turn over and very nearly refuse to start. Not sure if there is any way to test for this short of checking the current draw of the starter when it exhibits hard starting. Something to keep in mind if other avenues don't pan out.

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Anytime there is a hard starting situation (as opposed to slow cranking), the fuel system must be evaluated for proper operation.

 

One thing that can cause an extending cranking time, not necessarily only when warm or hot, is the fuel pump relay located on the center firewall.  It is the passenger side relay.  There is a backup power circuit for the fuel pump via the oil pressure sender, but that does not kick in until there is sufficient oil pressure which means that the engine has to crank for a time before that backup circuit will engage.  On the 88/89, there are 3 firewall relays (right=ABS, middle=brake pump motor, left=fuel pump) are IDENTICAL, so when there is any question about the fuel pump relay, just swap one of the other two over and see if that changes the behavior.  I am not sure if there was a change on location in the 90/91, so you need to check in the FSM for location of the fuel pump relay.  If you need a new relay,  the EXACT replacement can be ordered from Autozone (Everco # 35744).  There are a number of other relays that are electrically and connector-wise identical but lack the proper attachment slot on the rear to holds the relay in place on the firewall.  FYI, a lot of us carry a spare relay in the car as this is a fairly common failure point and one to remember when extended start situations (as opposed to cranking) occur.  

 

You also need to check the fuel pressure on the injector rail.  When you first turn on the ignition, for a 2 second period, the fuel pump is powered up to pressurize the rail.  It should read between 40PSI and 45PSI at the Schrader valve located on the right front area of the rail.  The rail should hold that pressure once the fuel pump powers down for at least 15 seconds (longer is better).  If it does not hold pressure, then either there is a leaking injector or an issue in the fuel tank.  In the fuel tank there is a device located above the fuel pump know as a pulsator.  It just presses over the fuel pump output as well as the fuel outlet line.  Ethanol in the todays gas plays hell with the rubber material in that device over time and it will begin to loose its seal against the pump and outlet line allowing fuel to leak out (low fuel line pressure/quick bleed down).  If you replace the fuel pump with a modern turbine design like offered by Bosch, there is no need for the pulsator.  Of course, if worn out, fuel pump can cause low fuel rail pressure.  If the fuel rail pressure is not above 35PSI at all times, the injection system will not operate reliably.  FYI, a new fuel pump is NOT a guarantee that the pressure will be correct.

 

You also mentioned that you had replaced the coil, but you did not say if you replaced the ICM (the module underneath the coil).  You stated that the coil had failed and coil failure can damage the ICM.  If you have not replaced the ICM, I would do it given the coil failure.  The ICM, in addition to powering the coils, reads the crank sensor and the cam sensor outputs and buffers those signals to the ECM which in turn controls the fuel injectors.  This device can cause starting and run issues when hot.  Wells Electronics (also sold by AutoZone) did a redesign on the ICM with many improvements.  This newer design is more heat tolerate and most importantly fires the engine within 1/3 of a revolution on startup.  The OEM design spec was within 3 revolutions, so this newer design results in faster startups.   Also the OEM coil design has been improved to better insulate between the primary and secondary windings on the coils.  OEM designs are still sold, but you can typically spot the newer design by its slightly higher price.  FYI, there are NO codes for ICM or fuel system.   

Edited by drtidmore (see edit history)
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Guest loupet

Thanks to KDirk and  drtidmore for your input. I have replaced the icm with a new one. As far as the fuel pump relay and the starter issues, have not addressed them yet. I`m going to replace the coolant temp sensor. Hope to replace the fuel pump relay. I understand that the fuel pump relay is in the center console on the driver or pass side?

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8 hours ago, drtidmore said:

Anytime there is a hard starting situation (as opposed to slow cranking), the fuel system must be evaluated for proper operation.

 

 

Quoted above is the first paragraph of a long post you made about hard starting. I found it all to be very useful. I think it would be helpful to anyone having a similar problem. With your permission I would like to add it to ROJ. If you approve I would like to make some small changes to the layout or wording instead of coping it verbatim.

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Guest loupet

I must let you guys know that now the hard starting issue when warm or hot seems to be corrected. It`s no longer a problem. Thanks to you all for your help.

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Guest loupet

Well, I`ll tell you what I replaced and, don`t know if that corrected the problem. Replaced the crank shaft sensor besides the new ac system (probably not related to this problem) fuel pump and, filter. Used the car today and got hot, shut it off for maybe 10 mins then, started it up and had no issues. So far so good. The major problem now is the dash in and out and, the ac clicking on and off and blowing through the defrost. But, alreading you guys are helping me with those issues.

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Guest loupet

From your experience with these cars, that will  solve my cluster issues? Get a cluster install it and, problem solved?

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