Recent content by adam_q

Update - Phoned up Jeep for a new CPS - wait for it - £100. So that's $140 of your Earth dollars. Luckily my (admittedly expensive) scrapyard had one for £36. Kooks like an original Jeep one, too. Fitted today and it's runing again! Problem solved. It seems that you get no fault codes for a...

OK so today I attached an oscilloscope to Pin 8 (the CPS input) and there appeared to be no activity during cranking - no pulses coming in (at least, nothing down to less than 0.5V, and noise triggering the 'scope below that.) I'm therefore thinking that this is indeed the problem, and the CPS...

After doing a bit more searching on the web it seems that I have been labouring under a false impression slightly - the ASD relay only pulls over for 3 seconds when ignition is turned on, then it opens again. However, it should pull over again during cranking. So this is the normal sequence of...

Here's a list of the reading I took from the PCM multiplug, where there's a difference, "ignition on" is marked with * and cranking with **. Where my wiring colour differs from the '97 manual I have put the colour in (brackets). I have added the circuit function is in [square brackets]. I also...

Here's a list of the reading I took from the PCM multiplug, where there's a difference, "ignition on" is marked with * and cranking with **. Where my wiring colour differs from the '97 manual I have put the colour in (brackets). PCM Connector A1 - A2 (BLU) 12V* 10.8V** A3 - A4 0V A5 - A6 -...

Yes the Cam position sensor is fine, I see +5V,0+5V,0, alternating on cranking. A bit later on I will post up all the readings I made from all the inputs in case that flags up something to someone. I of course substituted the ASD relay for known good ones (there are 4 others to choose from in...

.. and what exactly am I looking for, a P56041 297, or are there any other numbers to look for? One further update - I started investigating pulling the relay over by grounding the PCM control and noticed that the PCM does in fact pull over the ASD for about 1 second just when you switch on...

Next update - all inputs check out OK, including the CPS. Nominal or varying voltages on everything as expected, and measured at the 3 multiplugs. The CPS outputs 0.01V with ignition on, and during cranking around 0.17V. This would means around a mark/space ratio of around 3% and 5V pulses. I...

Thanks for the pointer. I had intended looking at the CPS at some stage, but up till now I hadn't considered it because the sequence of events is: 1) turn on ignition 2) note that ASD hasn't pulled over 3) turn ignition one click to start - we are now cranking Now the CPS will only come into...

OK so I was just checking I wasn't trying to fix something that didn't need fixing. If the ASD relay should pull over on "Ignition ON" and it isn't on mine, that's the first thing to fix. If you scroll up this post to the photo's you can see the PCM has 3 plugs so that's '96 onwards. After I...

Searches are coming up with "ASDR" too so that was a good call. I have one question: when should the ASD pull over on a healthy car? 1. Ignition on not cranking 2. Cranking 3. Running

Thanks for the suggestions - the ASD relay provides the coil primary 12V, so if it isn't pulling over to start with then all bets are off regarding the ignition. What fault codes can you read with the reader that don't show up with the "ingnition on-off-on-off-on-off-on" method? I'll give it a...

OK so the plot thickens. All sensors checked from the ECU/PCM plugs look OK, e.g. TPS varies linearly, MAP sensor wiring is OK (MAP sensor operation not confirmed yet), temp sensors look like arounf 10k ohms (cold), Park/Neutral switch working, all injectors read around 16 ohms, field coil...

It's a good question about the year - see my other post with the picture of the PDC which looks nothing like either the '95 or '97 Service Manuals I have picked up from another site. I'll take a pic of the ECU/PCM to help identify it. Presumably the other unit you are referring to is a Timing...

ASD = Automatic ShutDown PCM = Powertrain Control Module (i.e. the ECU)