While my 98 XJR in the shop getting an engine replacement, I've been driving my 86 sovereign XJ6 daily.....but now it won't start. Thank god for my wife's VW so I can still get to work.

It (the 86 XJ6 sovereign) ran perfectly before the no start, which makes me suspect it's electrical. It just turns over and won't fire up (obviously not the battery). So far I've replaced the distributor cap, distributor rotor, and the spark plugs. I've got nice strong blue spark coming from the coil to the distributor, and I've got spark (although smaller) coming from the distributor to the spark plugs. Perhaps the spark coming from the dist. to the plugs is too weak - I don't have enough experience to tell. I guess I could replace the spark plug wires, but the current ones have less than 1000 miles, so I really doubt that's the problem.

So then I start thinking fuel, even though my gut tells me electrical. 1st off, the car is definitely not out of gas (probably one of the leading causes of a no-start). I replaced the fuel filter - no luck. The fuel pump seems to be turning on and pumping fuel.

This car has an "ignition amplifier", a little box that connects to the distributor. Could this be it? I'm not sure if a bad amplifier, or bad connection between it and the distributor would cause a no start.

Also, there's this "thing" next to the fuel filter that I'm curious about (in the trunk). In the embedded picture, it's the thing that looks like a steel, hexagon cylinder in the middle of the picture, with two fuel lines coming out of the side, and one out of the top. The fuel line coming from the fuel pump goes into the upper, side input. Does anyone know what this is??? It looks like it splices out the fuel line from the pump into two lines, but I can't figure it out. The reason that I suspect this may be involved is because you would think that fuel should flow through it; however, when I blew into the lower, side fuel line, it was completely clogged....when I blew into the upper side fuel line, air came out of the top, and vice-versa. I really have no idea what this thing is, or does. Does anyone else know?? My Haynes manual is only slightly more valuable than used toilet paper.

I don't expect anyone to magically diagnose my no-start from this info, but any wild ideas would be appreciated. I'd also like to know that the hell that thing in the picture is. Thanks......

[IMG]local://upfiles/2329/66D4B32258B840E98FF89694FD2129DD.jpg[/IMG]

 

somethings to check:

1) the Inertia Fuel Cutoff Switch, located in the passenger side, behind the lower corner of the dash, above the kick panel. Check to see if it is tripped by pressing the buttonon top of it, you will need to pry off the black plastic cover over the switch assembly. This switchhas a spring-button, just like a tripper button. Push it down, it should click.

2) place the shifter in 1st gear and turn the ignition switch to start the engine, it will not start but you are supposed to hear the fuel pump charging, a buzzing sound. If no sound, that's a bad fuel pump.

3) check the Cold Start Injector, located to the right of the 90 degree aluminum elbow at the intake, facing down, with two allen bolts, a black electrical connectorand a hose connected to it, they have a brown or a blue plastic body. Remove the two allen screws, carefully pull the injector without tearing the gasket, have someone momentarily turn the ignition switch and see if a jet of gasoline comes out of it.

4) have you checked the connections at the Coil? Is the coil leaking? Bad coil.
5) I am not sure if the hexagonal valve in the picture is part of the Fuel Evaporative System, or the Tank Changeover Valve.

Jose

 

Jose thanks for the tips. I think the coil is fine (strong spark going to the distributor), the fuel pump is kicking on it's not the fuel cutoff switch and I haven't yet checked the cold start injector, maybe I'll check that out later today. I even replaced the ignition wire set....wasn't that either. That thing in the picture is not the tank changeover valve (I can see where that is), so maybe you're right about it being part of the fuel evap. system. I'm still suspicious about the bottom valve on this thing being clogged, but who knows. I wish I knew how it was supposed to work.

Occasionally if I haven't tried to start it in while, it will actually fire up and then die a split second later this is leading my to switch my focus to the fuel system. After that, it's just engine turning to no avail. I think if I had a good manual that would help, but I can't seem to find an online manual anywhere for an 86 Xj6. The fuel system description in my Haynes manual is completely geared towards carb systems, which doesn't help me much.

Not sure where to go from here.

 

good that you checked all those items. The Factory Service Manualtakes you on a process of elimination, and that's what you just did.

you can buy the Series III XJ-6 Factory Manual in different places:

http://www.lbcarco.com

http://www.jaggraveyard.com

Around $25.00 for the CD rom.

I do not think the Fuel Evaporative System would prevent the engine from running, it's just a fuel-vapor collector.

I wouldcheck the Fuel Injectors Diode Pack, a sort of a relay located next to the fuel pump relay which I'm sure others are more experienced diagnosing. Though the Ignition Amp could also be the culprit, and that's a GM part found at NAPA.

you can find thepart number here: (XJ-6 Parts Interchange Page):

http://tinyurl.com/2svyfe

Anotherknown cause for no-start conditions is the Ignition Switch itself. Wear in the contacts cause the switch to lose contact after starting and shut the engine off. If you can get the engine to start, try holding the ignition switch in the RUN position, slightly holding it forward,and see if that keeps the engine on.The ignition switch can be disassembled and rebuilt, just like the Wiper and Turn Signal switches can be.

Also, is the battery fully fully fully charged?

Jose

 

I'll follow out your suggestions and report back. The battery was fully charged at first, but i doubt that it is now after trying to start the car unsuccessfully about 30 times (kept trying after replacing, or messing with various electrical components)..

 

Jose,

Got it fired up and running like new! I'm pretty sure it was one of two things: 1) a bad/loose connection at the cold start relay.....or 2) a bad/leaky wire from at the "Thermotine Switch", which connects to the cold start injector. Impossible to say which one, but all I did from 'no-start' to 'start' was jiggle with the cold start relay connection, and insulate via electrical tape a crummy wire at the thermotine switch.. Knock on wood, it seems to be good.

Thanks a bunch your suggestions had me fishing around the cold start injector circuits/components, which may have, at least temporarily, solved my problem. At least I can drive one of my jaguars now.