Intermittent Misfire And Not Starting

[CaptainP 2]

My CTI has developed a rather annoying fault recently and I'm hoping for some advice.

 

A couple of months ago it started behaving differently, not sounding as if it was running smoothly and the occaisonal hesitation. The next thing I noticed was that occasionally when trying to restart when the engine was warm it wouldn't fire immediately and required several cranks to come alive. I changed the ignition amp module for a spare one I had (no guarentee that it's a known-good one) and it seemed better for a week or so and used it for a couple of trips locally. Yesterday I drove into town with no problem. When I came out and tried to restart about 10 minutes later it wouldn't go, I tried a good few times and had a couple of backfires which I've never experienced before. I checked all the basics like injector connectors, coil connectors, plug leads, distributor cap, and ignition amp connector but they were all good. Things even got deseparate so I called the AA for the first time in 8 years. He took 2 1/2 hours to arrive, and by that time the 205 had started up again. He suggested having the injectors cleaned and replacing the leads & plugs but those components are not that old really, and I can't see how they all would go as even if a lead failed it would start on 3 cylinders???

 

I was wondering if the ECU temp sensor would cause this problem. I did pop a new in about 3 year ago when I went right through the car replacing old bits that looked a little haggered or am I looking in the wrong direction and should be concentrating on a good ignition amp/distributor/coil?

[smithy 1]

Personally I would disregard what AA said.

 

Sounds very much like ignition system related as once cool starts up again.

 

Fault could be dizzy,coil or amp aswell as the tachy relay,first off I would check for spark when cranking and work from there.the tachy relay is controlled by the ignition system this then provides feed for fuel pump and injectors.

Edited January 21, 2011 by smithy

[splant 0]

sounds same as my problem [see noisy fuel pump 3 posts below] i was just about to add to that post that it happens after been sttopped a bit ,,,, new coil dizzy rotor didnt cure mine,,,please let me know if you cure it ,i thought it might be the temp sensor under the dizzy but when its running ok even disconnecting this doesnt make it happen again..its a pain in the butt that we cant even work out if its ign or fuel related..

[CaptainP 2]

Thanks Smithy, and splant I'll keep you posted if I make any further developments. I'm sure it's an ignition component breaking down.

Tell me about thermal paste for the ignition amp as I think mine is dry as a bone, would CPU paste work as used on computer processors as I have a tube of that?

[large 33]

Yes that is fine.

Ecu temp sender could be the problem have a good look at the plug onto it and check you have a good earth off it as well.

[CaptainP 2]

Getting quite annoyed with this now as it's leading me a merry dance. Swapped the ECU temp sender last week and thought the problem was cured, but today she let me down again after being stopped for about 10 mins. Came back to the car an hour later and with a bit of a misfire got her running again. There's a chance that the ECU temp sender I used was also faulty as it's an old one. To measure the resistance do I just stick a multimeter on the 2 terminals and put the meter on ohms?

[large 33]

Yes thats it. It should be about 2500 ohms at 20 degrees C and 250 ohms at 90 degrees C.

Edited February 9, 2011 by large

[bucky 3]

I had the same issues with my cti last year but every time I tried to trace the problem it would work! After replacing all the usual ignition parts it turned out to be the distributor after it finally died for good. I would definately recommend swapping yours with a known working one as your problems sound identical to what i had.

[CaptainP 2]

May have found out why I've been suffering the misfire and bad starting. One of the terminals inside of the dizzy cap was looking a bit worse for wear. Replaced the cap and so far so good.... I'm hoping that's it sorted *everything crossed*

Edited February 21, 2011 by CaptainP