HOrnbrod Posted December 5, 2012 Share Posted December 5, 2012 Before I start throwing parts at the thing, I have one of these intermittent ignition problems that are hard to track down. This is mainly directed to those who have a DRB II scan tool like Cruiser. I can drive for weeks with no problems, the out of the blue while driving along sedately on level ground the ignition cuts off for a second, then immediately cuts back on. It cut off twice yesterday, the most it's ever done. I have a Unichip on it but have it bypassed it until I figure out this problem. Once I had a coil go bad causing this same problem, but I replaced that. I know all the things that could cause this (CPS, TPS, even the ECU, etc.). No codes except a 14; MAP sensor supply voltage too high or low. The supply voltage reads 5.2VDC which I think is okay since my FSM gives no voltage tolerances. No problems starting either hot or cold. I've also cleaned the connectors. Parts replaced so far: IAC, MAP, coil, clean throttle body, plugs, cap, distributor wires. My question is will a DBR II scan tool point out the problem? I suspect it would not because it a rare intermittent thing, but I don't know. The local dealer still has a DRB II. Worth bringing it in? Link to comment Share on other sites More sharing options...
87MJTIM Posted December 5, 2012 Share Posted December 5, 2012 Sounds like my issue years ago. Engine would cut off while driving, then come back on. Finally, while driving home one evening - on the Wash beltway (while passing the Castle Oz - those in DC know this) - it just cut out. I coasted to the shoulder. It would not start. Diagnosed as CPS. Link to comment Share on other sites More sharing options...
cruiser54 Posted December 5, 2012 Share Posted December 5, 2012 I doubt the DRB will pick it up. Howzabout doing a "wiggle test" on all parts of the engine harness with it idling? Link to comment Share on other sites More sharing options...
HOrnbrod Posted December 5, 2012 Author Share Posted December 5, 2012 I doubt the DRB will pick it up. Howzabout doing a "wiggle test" on all parts of the engine harness with it idling? I wiggled all the engine management connectors I could lay my hands on including my self at idle, no effect at all. Since I had the fault code 14 I verified the MAP input and output voltages against the MAP connector ground, they were all within. I disconnected the battery to clear the reset the codes and just have the normal 12 and 55 codes now. Come to think of it, I never cleared the codes after replacing the MAP last month; wonder if that could have caused the problem? Link to comment Share on other sites More sharing options...
Akula69 Posted December 6, 2012 Share Posted December 6, 2012 Just a shot in the dark: Have you checked the ignition switch down on the column? The 93 my daughter had was doing the same thing, and it ended up being the switch. It was partially melted and making intermittent contact. Link to comment Share on other sites More sharing options...
HOrnbrod Posted December 6, 2012 Author Share Posted December 6, 2012 Forgot about that one - will do. Thanks. :thumbsup: Link to comment Share on other sites More sharing options...
cruiser54 Posted December 7, 2012 Share Posted December 7, 2012 I wiggled all the engine management connectors I could lay my hands on including my self at idle, no effect at all. Since I had the fault code 14 I verified the MAP input and output voltages against the MAP connector ground, they were all within. I disconnected the battery to clear the reset the codes and just have the normal 12 and 55 codes now. Come to think of it, I never cleared the codes after replacing the MAP last month; wonder if that could have caused the problem? Did I read that right? You wiggled YOURSELF at idle? Link to comment Share on other sites More sharing options...
HOrnbrod Posted December 7, 2012 Author Share Posted December 7, 2012 Did I read that right? You wiggled YOURSELF at idle? Yep, when I grabbed the coil HV wire like a dumbazz. :eek: Made me dance a bit. I had a spare so replaced the CPS today and took a 50 mile or so drive, no problems. Because I disconnected the battery last night to clear the MAP fault code it ran rough at idle as the HOs always do until the ECU "learns" the new settings. Wish there was a way to speed up the process. She's running great now - hope that was it. :crossfingers: Link to comment Share on other sites More sharing options...
Automan2164 Posted December 7, 2012 Share Posted December 7, 2012 Don, previously I have had some loose fuses in the fusebox knocking around that bit me in the butt. I was determined that it was a short in one of the splices in the dash, so I broke out the wiring diagram and partially pulled the dash down. It wasn't until I did all that work as well as de-looming part of the main harness down the drivers side kick panel that I traced it back to the box. The slightest touch was enough to make it act up, even though I could drive for ages with no effect. Now when I have the problem, I just wiggle the fuse. Rob Link to comment Share on other sites More sharing options...
HOrnbrod Posted December 7, 2012 Author Share Posted December 7, 2012 Thanks. Was it a certain fuse, or the fuse box in general? Renix or HO? Link to comment Share on other sites More sharing options...
Automan2164 Posted December 7, 2012 Share Posted December 7, 2012 Renault. My problem was a lighting problem, but it just as easily could have been any of the other fuses, including IGN. What had happened was I think at one point in time, someone had kicked the fusebox, or something had gotten up there and pushed the fuse, spreading the blades of the fuse holder. It would look and appear fine, but every few weeks, would break contact just enough to cause the fault. It was frustrating because every time I would check the circuit, I would put the test lead on the pin of the fuse, it would hold it in place and make good contact. I moved on down the line because I thought everything at the box was good. I sent myself on a witch hunt, determined for it to be some overly complicated problem. Turns out the simple stuff bit me in the keyster. Rob Link to comment Share on other sites More sharing options...
HOrnbrod Posted December 7, 2012 Author Share Posted December 7, 2012 Yep, that happens to all of us. Got to remember to K.I.S.S. first try. Link to comment Share on other sites More sharing options...
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