My dad put a 350 engine, plus the ignition and fuel system (including the ECM) from a 1989 chevy R-10 in a 1959 apache. One of the last things he told me before he died was it was running fine the last time he drove it. Truth is the last time he drove it he was still putting it together and was probably sitting on a 5-gallon bucket. The problem is it runs fine until about 25MPH and then it shuts off. If you let it coast , it will start and take off again when the speed gets back down to about 15MPH. I ran my timing light inside the cab and learned that it does stop firing about 25MPH and starts firing when it coasts down with the clutch out. Does not matter if I am in 2nd or 3rd gear so I don't think it is tied to RPM.
I used to work on these things in a previous life but I have forgotten most of it. Thanks to eBay I have a scanner old enough to read the computer so i have checked all of the sensors. The only two that are not currently connected are the O2 and Park sensors. O2 should not be a problem. I am wondering about the park sensor. It is a straight shift but the computer came off an automatic. Right now it thinks it is in park. Will the computer shut the engine off if it thinks the truck is going 25 MPH in park?
Thanks in advance for any advice. I am considering ripping it all out and putting something more modern in it. Nothing like troubleshooting a 35-year-old electrical system in a 65-year-old truck.
curtis
Last edited by Peggy M; 10/17/2024 4:46 PM. Reason: added more info to the title
