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Hi folks,
Swear I saw someone asking about a problem that sounded like this recently, but buggered if I can find the thread, so posting for the elucidation and edification of all....
http://www.asashop.org/autoinc/march99/techtips.htm
Coles notes: If clutch is wrong it can shade the crank sensor, resulting in either no signal or spurious signals.
regards,
RW222
That's a good write-up on this problem. I'll make this thread a sticky and move it to the TIII section.
Thanks for the info. I was the post a few weeks ago about the clutch change/ no start issue. Actually, my buddy ownes the car, which I was going to buy- but decided not to. He hasn't had much time since to look at it, but I will post when we find the problem. thanks again. Ben
could the pressure plate, could be the flywheel if you repalced it with the wrong one. supposedly i hear lately of ppl breaking the crank sensor upon install of a new clutch. i just did mine with no issues so maybe its just poor installation practices.
I am dealing with the same thing right now on my 93 R/T.I will be pulling the trans back out soon and will try and get pics of the differences in the plates.
Doug
Link broken :(
We need to start mirroring this information since it goes away too often :(
Sourced From: http://www.asashop.org/autoinc/march99/techtips.htm
© 1999 IDENTIFIX. All Rights Reserved.
Quote:
I got a call about a no-start on a 1991 Dodge Spirit with a 2.2L turbo III engine. The customer drove the car in to have the clutch replaced, and then couldn't drive it out because the car wouldn't start. The technician couldn't find any wiring that was disconnected or looked damaged but felt sure that he must have damaged something - somewhere - somehow.
Quote:
This vehicle had an uncommon engine package: 4 cylinder, turbo charged, multiport fuel injection package with DIS and a head made by Lotus. There weren't very many of these made, so, not surprisingly, the technician really didn't know where to start. He said there was spark, but only sometimes. The same was true of injector pulse; it would come and go. My first thought was to check the crank sensor and cam sensor patterns with a labscope, but since he didn't have one, I asked him to check for power to the coil pack while cranking. That was OK.
Next, when the outputs were checked using a scan tool, I found that the PCM could actuate each of the ignition coils and create good spark during an actuator test mode (ATM) and that the PCM was able to control each of the injectors. Why wouldn't the PCM give consistent spark and injector pulse while cranking?
Looking at the inputs again, the scan tool displayed "yes" to both the crank sensor and the cam sensor during cranking. This only shows that the PCM sees some kind of signal - it doesn't prove the signal is correct. The crank sensor signal should be a 5-volt square wave signal. For every revolution of the flywheel, the hall effect type sensor reads two groups of four slots, resulting in a scope pattern that shows the signals coming across the screen in groups of four "highs." The cam sensor is also a hall-effect type of sensor that creates a 5-volt square wave signal, but its pattern is different. The cam gear contains four sets of slots - a single slot, double slot, triple slot and a quadruple slot. On a scope this comes across the screen as a single "high" 5-volt square wave followed by a set of two highs, then three highs, and then four for every cam revolution. The technician rotated the engine by hand while watching the voltmeter switch from 5 volts to 0 volts, but still that didn't prove the signal was correct, only that it was present.
From previous experience, I had a strong hunch that there was a problem with either the cam sensor signal or crank sensor signal. Logic suggested that since the cam sensor hadn't been disturbed, it was probably OK and that the crank sensor signal was probably the culprit.
Since the sensor itself seemed to work, was there a problem with the slots that the crank sensor was reading? It turned out that the clutch pressure plate was not the correct application, even though it bolted on OK. The metal flange around the outer edge came too close to the cut-out slots in the flywheel. This interfered with the magnetic flux that acts on the sensor so that it did not "read" some of the slots. The PCM was so confused, it didn't know what to do when. It would begin to turn one of the coil packs on and off but then quit because it couldn't figure out where top dead center was. The next start attempt would do the same thing.
After the correct clutch pressure plate was installed, the engine started and ran beautifully. It's just too bad the incorrect pressure plate physically bolted up and worked OK. Sometimes we're too quick to blame ourselves. It wasn't the tech's fault after all.
Jeff Knowlen, IDENTIFIX Repair Hotline Chrysler specialist, is ASE master, L1 and Compressed Natural Gas certified.
Hopefully that is legal to do, lol