I have a ramcharger with a magnum crate motor. I am trying to swap the intake and electronics from a 99 Ram. The stuff came off a running driving truck. I got it all together and it will start and run. I am having to big issues. The biggest is it will start and run till it reaches operating temp and will stay running till I shut it off then it will not restart till it cools back down. The other problem is I cannot get any codes or info with a scanner. I tried 2 different scanners and it keeps telling me that it can not communicate. I checked the scan plug and it has power and ground and wires in the correct spots. Thanks for any help.

so pretend it isn't efi.

when it is at op temp, does it run and drive normal? from a stop? idle? reved up?

when you shut it off, and try to restart, are you still getting spark?
fuel pressure?

if you hold open the throttle will it restart? foot on the floor basically.

It runs better cold then warm when warm timing seems off the computer sets the timeing. Im not 100% sure the distributer is snyced right I did it with a meter but kind of need the scan tool to work to set it.
When I go to restart no spark has fuel preasure.

The computer thats in it is from a auto truck. I do not have any of the wires for the trans hooked up. I figured would see if there where any codes for it before I worry about them. I also see that a 99 up truck uses a dash computer for the check engine light and some of the gauges. I do not have that hooked up.

You really need to have everything from the 99 (cluster, body computer, PCM, TCM, etc.) to really know what is going on. PCM must match the sensors, etc. I was sent the wrong PCM for my Durango (Cal emissions instead of the correct Fed). I had two issues, including an incorrect intake air temp reading (could have been a bad computer or the emissions difference).

as for the no restart issue...could be anything, I would expect there to be a code if a sensor is going bad under heat.

Are the O2s hooked up? On an auto trans, you REALLY need the trans hooked up, or run a manual trans computer. the automatic in the late model trucks were electronically shifted by the PCM, and if the PCM cannot see the automatic to know that it's been shifted into drive, then the PCM thinks you're still in neutral, and will not let you rev past about 3500 or 4000, as a "I'm smarter than you and won't let you blow up the motor" safety device. Obviously, manual transmission trucks don't have this feature and will work great with a 727 auto.

I have the up stream o2 in the pipe the down is hooked up and out side the pipe. The truck is a 4 speed so I dont have anywhere to hook anything up to I did try hooking it to a valve body just to check but there was no diffenece. I have read that the pcm will not let it rev but will go 5000+. I really wish I could see the codes to know what was going on. I am thinking might have to find some obd 1 stuff to make it a lil easyer.

The serious scanners Matco, Snap-on and other high end scanners are whats needed to do any real diagnostic work, set the fuel sync and tune the TPS for maximum performance etc on the OBD2 systems. They also Data log which ever items you want them to. It's an essencial tool if you are having problems. I had an open ground on the heater for the O2 sensor, and was able to narrow it down because it went into limp home mode after 45 seconds after starting the car. All this was new to me, and that scanner saved me. I also bought an SCT Tuner from HemiFever and it transformed how the motor ran. It was amazing actually.

I am running a '98 3/4 ton, manual transmission truck ECM from Solo Electronics in Florida.

They don't have the security system in the key chip and don't look for the automatic transmission input.

Give them a call. They know these ECM's, and can likely steer you in the right direction.

I also run a O2 simulator for the second O2 sensor. Works great and shows perfect voltage variation on the scanner. I was told I didn't need to run anything for it at all, but it did throw the code looking for the input signal, so I cheated and used a simulator. I am running a bigger than stock cam and no cats.

Get the downstream in a pipe and put a muffler behind it. This burned us on the '84 Ramcharger with the '96 5.2. Don't let anybody tell you that downstream cannot affect driveability. That may be the entire problem.

I found my problem today. When I thinned down the harness I googled i wiring diagram and went off of that. Today I found a factory manual pdf and found a few differences. It runs ok now still has some issues but nothing major. Best of all the scan tool works.

Glad you got it. I was going to say to make sure you have your power and grounds at the OBD II connector as if you had that the sacnner should at least power up. I believe that PCM still comunicates on serial comunication as if it does you should be able to talk to it with no other controllers as all or most of the rest should talk on CCD or PCI comunication. Ron

Sorry to bring back an old thread but i was wondering where you found the diagram pdf you used?