Hard starting

Check and test the ignition switch could be coming from there.

I have done all that and replaced all the components. Fuel pressure is right where it should be and is working as soon key is turned.

No blown fuses, no vacuum leaks. The only time it does this is when its cold or has been sitting for about 30 minutes after driving. It will start right back up after it has been driven for a few minutes. The car runs excellent once its started. There are no codes showing up, battery is not the issue, fuel is not the issue. About the only thing i have not replaced is the ECM.

I have replaced the crankshaft position sensor to.

When it hard starts, there is no spark. Since i have already replaced ALL the sensors involved with this, how do i figure out which new part it is?

As far as we can tell, everything is working as is supposed to. Its like it has a cold start feature that is not functioning. And i think that has to do with the Engine Coolant Temperature sensor for the PCM. I have replaced that as well.

What sensor or "thing" would tell the coil "not to spark" when it cold or cooled off?

I have spent over $1200 over the last month on this issue with 2 mechanics and they cant find the problem.

The crankshaft position sensor tells the computer when to fire a specific coil-Could be the computer itself-Might want to have the ICM tested

I have replaced the crankshaft position sensor. I did put a new MSD coil in it to. Does the computer need to be reset somehow to accept the MSD coil? The new ICM (Ignition Control Module) was installed yesterday.

Will disconecting the battery reset the computer?

You can give it a try but bear in mind might make things worst that the computer has to go thru relearning itself again or be reflashed

Since it appears to me to be a "Temperature" issue, like when the engine has cooled off, does that most likely indicate the Engine Coolant Temperature sensor for the ECM to you?

Test the CTS resistances-Hot and Cold if its within specs

Hello, did you ever figure out what was causing your issue? ECT, ignition, third optispark...? Thanks.

Hi Jbuco315,

We never got to the bottom of this problem, but it sounds like it would be the distributor to me, because the computer must see correlation between the cms and the cks are it creates hard starting like in this case, the cam sensor is internal distributor style.

Let me know if you find anything

Best, Ken

Thanks for advice; I have now discovered that if I give it a single full pump of the gas pedal just before starting (on a cold start), it starts just fine. About a 1-2 sec turn of the key. Hummmm

New parts installed; Air filter, fuel filter, fuel pressure regulator, temp sensor, checked/gapped/cleaned plugs, tested continuity or wires, sprayed MAF with maf cleaner, and checked/rechecked all vacuum hoses and connections (i assume). FYI mine is a '95 Roadmaster with 52K on it.

Hi Jbuco315,

I am wondering if there are any codes, even though the check engine light is off, this can happens sometimes with a soft code, can you read the pcm to check please?

Also, without pumping the gas, just crank it with the throttle open slightly to see if it starts? I want to see if the IAC is operating when the key is turned on.

Best, Ken

Hello again, sorry its been so long. In my haste, I went out and got a code reader, once home I discovered that although its a '95, it was made in 'Oct '94 and is OBD 1. I do not have and adapter yet, still looking. Not sure if the codes would still be present, I disconnected the battery and then jumped the two leads together (to completely drain/reset the computer), thinking maybe it needed to go through the "learning process" again and might fix itself. But, yes, as you mentioned, there is No light, however it does work/light up at ignition on, like the rest of the lights.
Yes, holding the throttle open a little bit does help and it does still start right up and revs slightly before i can get off the gas.

Hey Jbuco315,

It sounds like the IAC is weak and slow, which would not set a code, this was a big problem back in 96, can you try replacing it?

Best, Ken

Great, I appreciate the help. Will start on this soon and let you know, Thanks, John

And VOILÀ. I pulled out the IAC valve and it was caked with black soot. I cleaned out its reservoir and the rest of the throttle body with spray carb cleaner until it ran/dripped clean. Also replaced the IAC with a new one, and wow, so far that seems to be it! This morning was approximately 50 degrees and with all the cleaner still floating around in the throttle body, it fired up within the first second and runs like a champ. I have shut it off and restarted it a couple more times after a short drive and all seems to be good. If things change, I will let you know. For now, thanks a million!! This was driving me nuts. I guess after 20 years a little sediment should be expected.

Hey Jbuco315,

Nice work! Glad to hear we got to the bottom of it and you are motoring once again! Please visit us anytime we are happy to help. Thanks for using 2CarPros.com

Best, Ken

UPDATE;
Ken, had to let you know this. I hate to sound like a teenager but, OMG!! Throttle response is unbelievable!! I have a 2000 Grand Prix GTP with the 3.8 Supercharged motor, well, this old LT1 has that beat hands down now! I have found I barely need to touch the gas anymore, but when I do, it responds. I would swear it is even shifting better through the gears as well as the/it's kick down. If I am under 35 and stomp on it, it will shift down, break loose a little AND THEN catch a chirp hitting second! And this is with very good tires on it. Now for the most amazing thing, I checked this twice, my mileage in now 18.1 and 17.7!! That's with I assume 85% in town driving (300 +/- miles each time). My longest hwy trip is only about 9 miles. Before, I was lucky to see 15. For as big as this car is, Dang, it's doing really good now!

Hey Jbuco315,

O wow! that is such good news, I like things that turn out better than expected, you must be living right! enjoy the car@!

Please use 2Carpros.com anytime, tell a friend!

Talk to you soon, Best, Ken

Wow I had the exact same problem! I replaced just about everything you had replaced and was dealing with two mechanics that couldn't find the issue and this car cost me money but never found the issue! This was so helpful so now I know to try to IAC! Thanks for the info