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-   -   1985 xjs V12 HE with Lucas ignition system (https://www.jaguarforums.com/forum/xjs-x27-32/1985-xjs-v12-he-lucas-ignition-system-217854/)

Weston 05-16-2019 07:59 AM

1985 xjs V12 HE with Lucas ignition system
 
so About a month ago I had the car running then I tried to start it the day after and nothing I wasn’t getting injector pulse so I adjusted the TPS and that seemed to solve that problem but still no start and I have strong spark, spark plugs stink badly of fuel when I pull them after trying to start, if there is anything you guys can think of I’d really appreciate it if I didn’t give enough info let me know and I’ll try to go over my situation in more detail, thanks

rgp 05-19-2019 04:27 AM

https://cimg4.ibsrv.net/gimg/www.jag...cf96733f50.jpg

Originally Posted by Weston (Post 2071448)
so About a month ago I had the car running then I tried to start it the day after and nothing I wasn’t getting injector pulse so I adjusted the TPS and that seemed to solve that problem but still no start and I have strong spark, spark plugs stink badly of fuel when I pull them after trying to start, if there is anything you guys can think of I’d really appreciate it if I didn’t give enough info let me know and I’ll try to go over my situation in more detail, thanks

on you battery main pos. lead there is 2 spade terminals, I have had issues with these being dirty and it wont start try that its an easy fix if that's what it is

Grant Francis 05-19-2019 07:43 AM

When you had it running, how long for??? Short running a V12, then shutting down, and trying to restart is not always a starter. They tend to overfuel, BUT, different markets have different Cold start. warm up, items.

It the plugs are WET, waaaaaaay too much fuel for any mode.

1) Many things at play here, and some are:

Dribbling Injectors.
EFI loom shorting internally, very common now.
FPR (2), Fuel Pressure Regulators, one on the front of each Inlet manifold, have ruptured internals. Pull the SMALL vac hose, and look for raw fuel, if dry, GOOD, if WET, NO good. You only need the FPR on the B bank (Left side), but more on that later, and NO, they are NOT interchangeable.

2) I will assume the "good spark" is actually AT the spark plug, and is a BLUE CRACKER of a spark. If not, the V12 will not start. Unplug a lead from a plug, #2 either side is easy, plug a spare plug, any plug will do, into that lead, and lay that plug so the casing is earthed on a metal something, and crank the engine, and note the integrity of that spark at that plug. If its Yellowish, then there are many issues to systematically work through. If its that BLUE CRACKER, refit that lead, and move on, all is sweet with the Spark dept.

3), Unplug the CTS, Xoolant Temp Sensor), located in the housing just aft of where teh B bank Top radiator hose attaches to teh engine. It has a 2 pin plug (the same style as teh Injectors plug). Take a paper clip, and shape it so you can bridge the 2 terminals IN the plug, not the sensor, and place that bridged plug somewhere that will NOT short it out. It only has a 5v feed from the ECU, but maybe a rag placed in the area just to be sure.
Reason:
The CTS is a PRIME fueling signal for the HE V12, and if you have a running V12, and unplug that CTS, you now have a dead V12, its that simple. Bridging the plug "fools" the ECU into "thinking" the engine is AT operating temp.Those CTS sensors can go flaky, and/or simply die.

4) If its simply flooded, and they can do that, TIME is all you got, so jam the throttles wise open, and call it beer o'clock for a day or 2, fact. OR, remove all the spark plugs, and wait 1 day, and then refit the plugs, NAH, 2 days beer o'clock, much better.

5) How old are the plugs???, if unknown, fit new ones while it dries out. I use NGK BPR6EF. I know that the "P" spec is NOT listed or the V12, and I have had too many of them to change my thoughts for anyone, but the "P" is for projected nose spec, and that puts the spark INTO the incoming fuel mixture, and does reduce this starting issue in its tracks. There is NO danger of the plugs hitting the pistons, and when you pull a cylinder head one day, you will see why I say that.

Weston 05-19-2019 04:18 PM


Originally Posted by rgp (Post 2072865)
https://cimg4.ibsrv.net/gimg/www.jag...cf96733f50.jpg

on you battery main pos. lead there is 2 spade terminals, I have had issues with these being dirty and it wont start try that its an easy fix if that's what it is


Thanks! I will check them tonight

Weston 05-19-2019 04:21 PM


Originally Posted by Grant Francis (Post 2072907)
When you had it running, how long for??? Short running a V12, then shutting down, and trying to restart is not always a starter. They tend to overfuel, BUT, different markets have different Cold start. warm up, items.

It the plugs are WET, waaaaaaay too much fuel for any mode.

1) Many things at play here, and some are:

Dribbling Injectors.
EFI loom shorting internally, very common now.
FPR (2), Fuel Pressure Regulators, one on the front of each Inlet manifold, have ruptured internals. Pull the SMALL vac hose, and look for raw fuel, if dry, GOOD, if WET, NO good. You only need the FPR on the B bank (Left side), but more on that later, and NO, they are NOT interchangeable.

2) I will assume the "good spark" is actually AT the spark plug, and is a BLUE CRACKER of a spark. If not, the V12 will not start. Unplug a lead from a plug, #2 either side is easy, plug a spare plug, any plug will do, into that lead, and lay that plug so the casing is earthed on a metal something, and crank the engine, and note the integrity of that spark at that plug. If its Yellowish, then there are many issues to systematically work through. If its that BLUE CRACKER, refit that lead, and move on, all is sweet with the Spark dept.

3), Unplug the CTS, Xoolant Temp Sensor), located in the housing just aft of where teh B bank Top radiator hose attaches to teh engine. It has a 2 pin plug (the same style as teh Injectors plug). Take a paper clip, and shape it so you can bridge the 2 terminals IN the plug, not the sensor, and place that bridged plug somewhere that will NOT short it out. It only has a 5v feed from the ECU, but maybe a rag placed in the area just to be sure.
Reason:
The CTS is a PRIME fueling signal for the HE V12, and if you have a running V12, and unplug that CTS, you now have a dead V12, its that simple. Bridging the plug "fools" the ECU into "thinking" the engine is AT operating temp.Those CTS sensors can go flaky, and/or simply die.

4) If its simply flooded, and they can do that, TIME is all you got, so jam the throttles wise open, and call it beer o'clock for a day or 2, fact. OR, remove all the spark plugs, and wait 1 day, and then refit the plugs, NAH, 2 days beer o'clock, much better.

5) How old are the plugs???, if unknown, fit new ones while it dries out. I use NGK BPR6EF. I know that the "P" spec is NOT listed or the V12, and I have had too many of them to change my thoughts for anyone, but the "P" is for projected nose spec, and that puts the spark INTO the incoming fuel mixture, and does reduce this starting issue in its tracks. There is NO danger of the plugs hitting the pistons, and when you pull a cylinder head one day, you will see why I say that.


Was doing a check of all the sensors and the CTS pins aren’t making contact whatsoever they look like they broke off or something and the spark plugs are bran new put them in right when I got the car the previous owner gave them to me, I will check over everything you listed thank you for the info, I’ll post later on and let you know what I find!


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