Alright I've got a question.. I've got a 99 s10 with a lt1 out of a 94-95 caprice motor it has a a4. I've replaced plugs, ICM, plug wires, fuel filter, another a sensor or two I've replaced just can't remember. Anyways there's no way to plug the truck in and check for codes it's obd1 and even if I plug the truck in its says no link. The problem I'm having is after I drive for a good 20 to 40 minutes depending on how hot it is outside and how bad I'm beating on it.. It will eventually start to run like crap have a very strange idle... Sometimes die .. Have a huge loss of power... Then ill park it and no more then ten to thirty minutes later its good to go.. It doesn't overheat eat oil or antifreeze.. Doesn't smoke bad.. I'm beginning to think its the knock module in the computer because it acts out of time.. Any input? I can't do the easy way out and just check the scanner for codes.. Any other way check the codes without a scanner? The paperclip trick dont work. Any help wold be great thanks! If it is the knock module which one do I need can i use one out of a lt4 vette?

 

You need to find out why you can't communicate with the PCM(try Shoebox's site for schematics).

Trying to troubleshoot modern EFI engines without pulling data from the PCM is going to be an exercise in serious pain(for you and your wallet). With OBDI you can look at engine data and there are codes for many failures and troubles.

I think freescan is free software for the OBDI PCM and from there you need an OBDI cable. Others on here know the OBDI PCM much better than I(mine is OBDII). Hopefully they will chime in.

 

under the hood the obd1 plug is accessible it's laying over by tHe drivers side Im not sure why but I'm pretty sure you can't wire it into the s10 ob2 plug.. Probably why its just layong there but Anyways if I get this off eBay
GM 12 Pin to OBD1 OBD2 16 Pin Connector Adapter Car Motor Diagnostic Tool Cable | eBay ..
And hook that up to my obd2 scan tool will that adapter work if i plug it to the obd1 plug under the hood and give me some info?

 

If your scanner does not do OBD-I, then it won't work.

 

I'm stumped and not many people wanna work on it

 

my guess is you need to get whatever cable to hook to the one under the hood and not worry about the in cab one. then get whatever software will work for the year of pcm you have it hooked too. I think the obd1 ones are datamaster and freescan. Another suggestion is try to contact a couple of the email tuner places and they could direct you. One of them rents the cables and software. The 95 looks like obd2 port and I think the earlier ones are different. I dont think you can jump anything newer than 93 but not sure on that. Focus on connecting to the one connected to the pcm.


Posted from Camaroz28.com App for Android

 

also I dont think that would be the knock module either unless you are getting false knock and only when warm. Sounds more like a heat sink issue and generally thats on the spark side of things. I believe one mod that may help is moving the coil and icm to a cooler location.


Posted from Camaroz28.com App for Android

 

I'm gonna try spacing the ICM off the block with some washers

 

You need to scan it first....otherwise you are like a surgeon operating on a patient blindfolded.....

Did you put the engine in the truck or did you buy it like this?

 

I bought it like this .. What exactly do I need to scan it? Do these symptoms give anyone any ideas?

 

Quick question I went to change my oil and looked at the knock sensor near the oil pan and the knock sensor is rusted like crazy and is in the block but has nothing plugged into it.. It's just a metal nipple.. Isn't it supposed to have a plug connected into it? What color wire is it and where does it come from the PCM? Will it be fine if I stays disconnected?

 

There is supposed to be a single wire plug on the sensor.



Be aware that the knock sensor doubles as a drain plug. If you remove it, coolant will come pouring out of the block. It's also essential that, if you install one, it gets torqued down to the proper spec. Too tight and you could damage the sensor and it could create false knock.

 

The knock sensor wire is dark blue.

 

Will it affect performance if is not plugged on? I believe I have two since its a caprice motor

 

I'd sure suspect there will be a performance difference. The knock sensor helps the PCM decide if there is too much timing in the engine. If it doesn't get feedback from a sensor it may go to a default condition. Default conditions are never good...chuckle.

If it pulls all the timing it can the engine will be a real dog....