As I posted in another thread, I've been working on my project xjs.

When I first got it, it started and ran with a little burnt oil at start. The few times after that I could get it to start, it would back fire when I let off the throttle, and definitely was not running on all cylinders.

Fast forward a bit, and it would not start any more. Barely turned over. My battery isn't great, but there's other issues for sure. I checked the oil level and it was way too high. After draining it, I noticed how much gas there was in the oil. I'm guessing this is due to the other issues.

What should I work on first? I have oil and a filter on hand, but can't find a big enough socket to remove the old filter. Close, but no cigar.

 

Gasoline contaminated oil does no harm sitting in the sump but can cause a world of hurt if you run the engine, obviously.

First find out why there is so much gas in the oil and repair that issue....then refill the oil and replace the filter.

One of many possible culprits is injectors staying open due to wires shorted-to-ground. The injector wires often crack after years of being baked by engine heat

Cheers
DD

 

I've noticed several injector plug wires that are cracked. Is there a readily available replacement?

 

Yes, new FI harnesses are out there.....$$$$$

Most guys make their own replacements.

Cheers
DD

 

Hm. Might have to attempt repairing it. Not enough clams in my bay for pricey big stuff. Not right now anyway.

 

They are asking around $600 for a new harness that someone has assembled. You can do it yourself for very little. I am going to build a new one for my car soon. I have the injector connectors in hand. The connectors are very common used on many cars and cheap new at all parts stores. Here is a link to Kirby Palms info on Jaglovers Jaguar EFI Injector Harness Rebuilding
A lot of people have done it and there is a lot of info available doing Google searches.

 

I would start with the basics plugs, distributor cap, rotor arm and wires. It could be worth checking if the leads are on the right plugs.

 

If it was backfiring when you let off the throttle and sounded like it was skipping, then it was dumping unburnt fuel into the exhaust. Bad plugs could be a culprit, but so could a stuck injector dumping too much fuel. That could also be why you have gas in the oil as it floods the cylinder and eventually seeps past the rings.
It sounds like your injector harness needs replacing and they really aren't that difficult to make. I've built several using high temp wire, solder, shrink tubing and a loom covering. However, if your injector isn't getting any signal, it shouldn't be opening. So if it were me, I'd first check the plugs and spark plug wires, then if it still skipped I'd start testing the injectors.

 

Injector connectors are available on eBay or you could buy a BMW V12 or 2 I6 injector harnesses and modify. They use the same connector and they use high temp wire, could be a cost effectve option.

 

Injectors stuck open by gumming or rust (water in fuel usually condensation from fuel tank) is rather too common, particularly with cars sitting still for longish periods. I Take them all out and bench test in an injector test rig. Then the stuck ones are subject to prolonged ultrasound cleaning which usually unstick them. Finally I run a bit of fuel through and wrap tightly in plastic until they are to be used again. Be aware that even injectors of nominally the same cc/min will be different if they are of another design than the original pintle type. Both flow curves and patterns will be different. Bad running in particlular at idle and low rpm will be the result.

And yes, one V12 started in -20C showed as usual lots of white smoke (condensation) which camouflaged the unburnt fuel from two cylinders with injectors stuck open. By the time the engine was warm and I twigged onto the impending disaster the crank was damaged.

 

That's a scary thought. How was the crank damaged? Wear on the lobes?

I'll have to look into cleaning the injectors. My instructor suggested that the valve guides might be shot as well as an injector issues, the slight blue smoke at start indicating the valve seal problem.

I'm going to look at patching up the efi harness as best I can, but my school doesn't have the facilities to test injectors. This is going to sound dumb I'm sure, but can I give the injectors a surface clean with brake cleaner?

 

Got the fuel injection harness out. Boy does it need work. Half have cracked wires, most have cracked boots.

 

Hi Pif,
My son and I found a neat little vid on youtube about how to clean injectors.
The hard part for us was getting the fuel rail put back together pressing all the short hoses back into place.
The cleaning process went well and you'll know right away if an injector is not working. You'll want to purchase all new orings etc, also you should index the injectors so they go back into their respective ports. No really a big deal, but I have been told that unless you can actually test their flow rate don't mix em up.
Our 89 xjs sat for 5 years before we got it. So we cleaned the fuel out and cleaned everything. Now she runs very well with just a few issues regarding tuning and that sort of thing. We are currently tackling the read inboard brakes.
Good luck
Peace
Neil

 

http://www.youtube.com/watch?v=wrOnXZWHhEQ

This is the last video of it running.

 

It could be my sounds system, but to me it sounds like it's missing on several cylinders. The unburnt fuel would explain the smoke too.

 

Crank: Scratched big end, and with these tuftrided crancs that spells "replace".
Injector creaning: The trick is to loosen up the pintle and flush out the rubbish. The problem is that the tolerances these things are built to are so close penetrants are not enough. At least that has never worked for me.