I have the paper work from it being changed in 2013. I know that’s 6 years, but it looks to be in very good shape.
Also, does anyone know what the coils resistance should be? I’m getting 7.29k ohms.
Hi Tony, I got my coil from Welsh Enterprises $36.95 + 14.50 shipping $51.45.
https://www.welshent.com/Search.aspx?k=dbc1140
In fact I have two of them. I was having issues with starting (still am) and while trying to get the positive terminal nut loose it broke the plastic it is embedded in so I ordered a new one. I installed it and the car ran fine for about a week then quit. I thought it was the coil gone bad so I had Welsh send me another one and they agreed to take back the first one and would give me credit for it when they received it back. That’s when I discovered it wasn’t the coil. I didn’t have the heart to send back the first one because it wasn’t bad. Joe77 mentioned my post to you earlier, it’s here.
Not sure I can be of much help to you given I haven’t been able to get my Jag running for over a month and I have many many hours running diagnostics. My last post #167 shows a trouble shooting matrix that may be helpful to you. I’ll keep an eye on your progress and if I can add any useful information I will be glad to help. Several years ago I was having some fuel pressure issues and made the following modifications to my fuel rail. I soldered a Schrader Valve to the end of the fuel rail, made measuring fuel pressure easy.
I ordered a new coil from Autozone, it’s a Bosch brand one. I hope that was my problem, I’ve had a weak spark cause fits on my other vehicles before, and it’s always been something stupid. Seeing this coil out of spec, I am hoping that’s the problem. I would really feel better if if found 1 part that was causing it rather than a bunch of small stuff. Like you mentioned the car would stall on you, I don’t want to deal with that continuously.
I like the idea of putting a Schrader valve on the fuel rail, I don’t get why there wasn’t a place to test fuel pressure from the factory? I ordered the tee fitting for the fuel rail, my plan it to plumb a fuel pressure gauge in and leave it in place. I just think if it was fuel it would of started on starting fluid.
These cars are surely “over engineered” lol. After completing a few carb to efi conversions using Megasquirt I feel I have a pretty good understanding of the efi process. Some of this stuff just seems too complicated. At the end of the day this engine is no different than any other, Compression, air + fuel, and Spark is all it should take to run. I have good compression, I’ve sprayed starting fluid in, the only questionable part is the spark.
I will get the coil today and I will report back with what happens. I think either way I am going to put the fuel pressure gauge in. A car with this many miles will eventually have parts fail.
Tony, you got a killer price on your Jag. You can afford to do some trouble shooting to get it right. I’ve had my 94 VDP for 17 years.
New coil and still a very weak spark. Ive tried start fluid and still nothing. I added a ground cable from the engine to the body. I’ve had the charger on it for hours, at 10 amp and 40 amp, and had jumper cables from my truck to it, but still nothing. I’ve tried with the fuel pump relay jumpered out.
It’s not throwing any codes, so it has to be something the Ecn doesn’t monitor or can’t see. I guess plug wires, cap and rotor next. I just don’t think that’s it, but I could be wrong. I am just so used to my old domestic vehicles where as long as the engine turns over and there is fuel it will run. These cars are quite delicate.
Here is a pic of the cap. It is pitted, but I just don’t know if it’s bad enough not to run.
I also want to add, I just tried a spark plug from the coils output and it was weak. So the cap and rotor are not to blame completely.
What brand and # of plug? What gap?
AC Delco, I wanted to get Champions but the parts store didn’t have them. They are gapped at .035.
The .035 gap is correct - which AC Delco plugs? Some forum members have reported problems with fancy-schmancy platinum, iridium, unobtanium, etc plugs. The good old copper core plugs like the Champion R9YC seem to suit these cars quite well.
The cheapest ones they had. Just regular copper ones. I’m not a believer in the fancy plugs either.
So I found a problem. Checking voltage at the coil with the ignition ON, I measured between a body ground, and both studs on the coil. Both measurements were .45v, and for reference I measured 12.07v between the firewall stud and that same ground.
Something I was thinking about trying was connecting a 12v+ Lead to the coil and seeing if that would let it start. Is that a bad idea?
I located the ignition relay and jumped it out. I have 12v at the coil. The battery is weak from me trying to crank it so much without it being on charge that I think it needs jumped to start now.
Is there a replacement relay from Autozone that I can buy that’s recommended?
Just grab another relay out of a socket on the car as a test. There’s plenty of them that should have the same (4 pin?) base.
Yeah, I have robbed un important ones like the AC relay to put in more important spots. I am just thinking about replacing all of them, it seems to cause a lot of grief with theses cars. I may try to take them all apart and clean them and test them. After I get this on the road I’ll be carrying spare relays like I do spare fuses.
12v at the coil and still not start. I had jumper cables from my truck on it, I may let the charger sit on it for a few hours then try. When I crank the car I am getting 9-10v at the coil. I know it will dip, but should it dip that much?
I also need to remove the grounds by the fuel rail and clean them.
Just be aware that some of the relays have a diode across two of the contacts, I forget which tow bu it is there to stop spikes. Its a long time since I looked but I think there is a legend on the side which indicates if the relay has a diode?
Some listers have retro fitted diodes to standard relays.
Ah I was not aware of that. I will be sure to look at the schematic on them before trying to swap them.
I don’t want to say I have given up, but I am lost. I’ve cleaned everything I can think of, and I even tried pulling the battery from my 3/4 ton Chevy thinking maybe the battery in the car was bad. Still the same result. It sure does seem like it wants to start but it just never happens. I would even say the spark is enough to make it run.
At the end of the day it’s still an engine
Air fuel
Compression
Spark
I have all three of those things, the only thing I have not verified and I don’t know how to is the timing. I assume it’s not adjustable, could there be something up with the CPS or the ignition module?
That’s really all that it can be.
done the cap and rotor yet?
No I haven’t, nor the plug wires either. I guess I should replace them to eliminate that possibility.
Something I’ve not mentioned that I’ve wondered since I checked the car out, it will go out of park without the key in. Is that normal?
Not from memory fairly sure that it’s interlocked, is there a star screw on the centre console? If there is that is where you would remove that to depress a release mechanism to disengage the lock out.
Just a thought, I suppose the plug leads are gong to the correct plugs?