- Location
- Salem, OR
It’s been a hot minutes since I’ve been on here, the jeeps been on the back burner for a good 8 years. But I’m trying to get it to run again and running into some ecu problems. Really need your guys help.
So I’ve been plagued by a weird issue that I can not figure out.
Pre-face: 97’ auto XJ 4.0L.
The thing has sat for years being on the back burner and when I got it into a shop to be worked on, they said the ecu was dead. They got it started by using a 99’ auto federal ecu.
NOW here’s the weird part, I have bought TWO 97’ auto federal 4.0l ecu’s from people. Both are 277AD. NEITHER will start it. Plug both 97’ ecu and the engine will just crank and crank and crank. Toss the shops 99’ ecu in and it crank a couple of times and fire right up. Even unplugged the 99’ ecu and swapped the 97’ right in thinking maybe it was fuel priming issue, and it’ll just crank and crank and crank. But immediately swap the 99’ ecu back in and it’ll fire up.
Now they said they put the original ecu in the passenger seat, when I went to look at it, it didn’t say 277AD, it said 534AE, which comes up as a 98’ auto federal., which was weird as fuck but I do remember like 8 years ago when replacing the Tstat, I broke the temp sensor and needed to replace it and when I got a 97’ sensor, the plug wasn’t the same. When I took the original to the parts store, it was a 98’ temp sensor.
So could my 97’ have a 98’ system? And would that make a 97’ ecu not fire up the engine but only crank? Is there a way to test a 97’ ecu to show it’s functional and works? I don’t really know where to go from here.
So I’ve been plagued by a weird issue that I can not figure out.
Pre-face: 97’ auto XJ 4.0L.
The thing has sat for years being on the back burner and when I got it into a shop to be worked on, they said the ecu was dead. They got it started by using a 99’ auto federal ecu.
NOW here’s the weird part, I have bought TWO 97’ auto federal 4.0l ecu’s from people. Both are 277AD. NEITHER will start it. Plug both 97’ ecu and the engine will just crank and crank and crank. Toss the shops 99’ ecu in and it crank a couple of times and fire right up. Even unplugged the 99’ ecu and swapped the 97’ right in thinking maybe it was fuel priming issue, and it’ll just crank and crank and crank. But immediately swap the 99’ ecu back in and it’ll fire up.
Now they said they put the original ecu in the passenger seat, when I went to look at it, it didn’t say 277AD, it said 534AE, which comes up as a 98’ auto federal., which was weird as fuck but I do remember like 8 years ago when replacing the Tstat, I broke the temp sensor and needed to replace it and when I got a 97’ sensor, the plug wasn’t the same. When I took the original to the parts store, it was a 98’ temp sensor.
So could my 97’ have a 98’ system? And would that make a 97’ ecu not fire up the engine but only crank? Is there a way to test a 97’ ecu to show it’s functional and works? I don’t really know where to go from here.
