Hey everyone,

I bought a 2002 Super V8 2 months ago in fairly rough shape; running rough, scratches and dents, and the like. I fixed it up and running smooth and started some minor body work. 3 weeks ago, it quit on me (and in a downtown parking garage of all places)! Now I've spent my fair share of time scouring these forums for a fix and I cannot find a resolution that has worked for me... This is my story:

I had taken the car to a Cars and Coffee event, ran a few errands around town, then parked it in the parking garage while I grabbed lunch downtown. At this point, I have no check engine light. When I went to start it up to go home, it just cranked. And cranked and cranked and cranked... While I was there, I checked all the fuses visually, swapped ignition related relays with know working ones, and poked the Schrader value (which gave a healthy squirt); Everything there was good. I thought it was possible I flooded the engine cranking it that much, but cranking with the gas pedal to the floor did nothing for my case.

I got a ride home, read about bore wash, went back to the garage and pulled all the plugs. Gave my cylinders a dabble of oil and BOOM! Nothing :/ I was optimistic in that my SYMPTOMS were the same as bore wash, but the CAUSE was wildly different and not applicable to me. Think about it; I drove it around all morning, I promise you the engine was fully warmed up.

Welp, I bit the bullet and got it towed home. There, I double-triple checked my fuses with a multimeter; good. I recharged the battery (not because it was dead but figured after all the cranking it was probably leaning towards the low side). I also checked for spark and found NO SPARK! Aha! Now that I found the issue, I could surely find the solution.

I scoured these forums until I found exactly what I was looking for... The Crankshaft Position Sensor. A bad CSPS will not provide good info to the ECM and the ECM will not send power to the plugs. Again, putting all my eggs in one basket, I replaced the CSPS with no luck. Still cranks, still has no spark.

Over the past days, I have continued to look on the forum, youtube, google, anything that could help. I haven't found what I'm looking for, but I HAVE seen how you all react to a "my car won't start" forum, so let me get the jump on you:

- I have read this: https://www.jaguarforums.com/forum/g...d-first-30792/
I get to step 3 and it says "Check for spark. If you have no spark, check your fuses and relays. If you still have no spark, sorry, can't help"

- People keep talking about "Gus's No Start Procedure" but every link I have found has been broken. Does anyone have a PDF version?

- I have also extensively read this: https://www.jaguarforums.com/forum/x...o-spark-71752/
In post #2, a member says to check for voltage at the coils with the key in the run position. In this case, there was 12V. Now in my case, I have 4V. This is worst case scenario. 12V and I could move on, 0V and I replace the wires from ECM to coil, but I have 4V.

So... anyone have good next steps for me? I've been on JagRepair.com - Jaguar Repair Information Resource trying to understand which pins correlate to which coil wires with the thought that I test to see if I can get 12V from the source (ECM) and see if I'm losing anything before the target (coil). I don't know. I'm really lost. This was supposed to be a fun summer car, but now I feel over my head

Help me fall in love with the cat again!

2002 Super V8 (X308, Supercharged 4.0L)
(AFAIK it's just a supercharged VDP)

 

The coils get power from a source X and the power is " sitting " on them at all times

The ECU provides individual grounds ( 8 ) to give a spark

See page 61 and ignition coil relay location see page 37 and 2 fuses # 18 and # 14 ( this # 14 requires the EMS CONTROL RELAY to close ) both engine management fuse box

jagxj2002.pdf (jagrepair.com)

 

I know this isn’t diagnosing per se, it’s about experience. I’ve run across a handful of times that the main engine electrical connector by the firewall that has a 10mm bolt in the middle of it needs to be loosened all the way (after you disconnect the battery) and opened up for evaluation. Clean, straight pins is a must. Be careful upon reinstall to not bend the pins. Micro-corrosion is also definitely a thing. It’s also a good time to check out all the grounds in the engine bay and clean as necessary. I think of it as a spare tire, forgotten about until you need it.

 

Can't find a version of Gus' No Start: but maybe one these might help

 

Thanks. I replaced the "engine to frame" cable, but haven't found any other obvious grounds. As for the "main engine electrical connector", is this the dual-side-nut looking thing in front of the computer (through the wall between the ECM and engine)? If not, is it truly through the firewall (cabin to engine bay)?

 

Jim, the troubleshooting pdf was great, but ultimately didn't get me anywhere. The .docx looked promising, but I can only read about half of each page; the formatting is wonky. Any chance you could post/PM me another file?

 

Using Word, reformat and open again. It be all I have

 

 

" I know this isn’t diagnosing per se, it’s about experience "

That has great value on this forum vs. paper chasing

 

Updating this for any others that come across it. Ultimately, it was Addicted2Boost's post about engine bay grounds...

I looked over the JagRepair schematics and found that I should be having 12v at the coils (which I was measuring the wrong coil pins!) and this was switch by the ignition coil relay. I had 12v to the relay "switch" (relay pin 1) as well as the relay "pass-through" (relay pin 3). I had swapped relays a replaced a lot with known, working ones. Unfortunately for me, it took noticing that the relay didn't "switch" upon pulling it out and putting it back in with the ignition in the ON position AND after verifying I already had power there... it just wasn't able to close the circuit with the bad ground (from relay pin 2).

I hope this helps someone! And remember, measure twice (and then measure a different way), be frustrated once.