Been a frustrating day. New plugs, wires, cap, rotor, cleaned injectors and fuel rail, and fixed the shielded wire around the ignition amplifier. Not so hard but tedious. Started the car, and ran really rough. Thought I had fixed that problem. Turns out, strange that it may be, is that the passenger side exhaust is even and hot. The driver side is sporadic and cold. I touched the exhaust manifold after it had ran for about 10 minutes. I didn't keep my hand there of course, but I could touch it without burn. This has the lucas system, so no half the distributor is not working issue. Pressure at the front of the rail, I just pulled the injector line and hooked up (didn't make any difference by the way) and got a jumpy 37 lbs.
I also pulled the exhaust from the back to the long tube that goes to the front. I did not disconnect the manifold. Also no effect, except I have to put it back together.
Thoughts would be great.
Thanks
Phil

 

Are the left side injectors clicking?

Cheers
DD

 

drivers side cam could be out of time. check the injectors first. hook up a vacuum gauge if you have one. im curious as to how much it pulls

 

Doug and M90power,
Just got around to computer time. I did check the injectors with the screwdriver to the ear, and they click. M90power-idle so erratic cant get decent vacuum read. I did pull an injector this morning, left it hooked to the rail and power, and tried to start the car. Injector did pulse and spray, so I think I can rule out injector issues. However, the sump tank was disgusting when I cleaned it out, stuff that looked like lava rock fell out. I have not replaced the fuel filter since I did the tank, so I bypass it for a test. I don't have the foggiest how the pressure regulators work, so it may not be letting enough flow. When it runs, a little bump on the accelerator kills it, and it sounds like a drum beat on the left bank.

 

Ok, good. We now know that they are functioning from an electrics standpoint at least






Probably so....if we assume that the other five injectors on the left bank are spraying OK





Yikes! Gotta get that cleaned out.




Now any crud goes right to the fuel rail !




A regulator problem wouldn't eveidence itself on just one bank of cylinders



And none of this was happening before the work mentioned in your first post? Or do I have that wrong?

Cheers
DD

 

I'm just going back to basic things to look at, Did you get your leads correct in the firing order? When you changed the leads are they seated in the dizzy cap properly or on the plugs? I found I had to push the wire through the boot and then seat them.
When you checked your dizzy was the gap from the magnetic pickup correct?
Only one other is there an air leak so the motor is sucking air from a pipe or somewhere else?
At first like Doug I would have said injectors are more than likely the culprit, and possible cooked wiring the cause, but if there clicking away it sort of puts aside that thought.
Firing order is 1R-6L-5R-2L-3R-4L-6R-1L-2R-5L-4R-3L

 

ok, so forget an accurate vac reading. what is the gauge doing? i want to know if the vac is fluctuating and if so how much and in what directions at what rpm approx.

 

Are you quite sure that the capstan is operating both throttles correctly?

greg

 

Well at this point seems like you have an ignition issue. I really cant help with that but a word of caution...Pull the fuel pump fuse or disable fueling some other way and concentrate on the ignition issue with a spark plug tester while cranking. The unburnt fuel probably has gotten past the rings and thinned the oil so you're probably due for an oil change now.

 

Wow, the suggestions are great. Okay, I will try to answer points from everyone
1. Cleaned sump but did not change filter afterwards, oops, but car did not run but about 5 minutes after filter change before sump cleaning.
2. Original problem was intermittent spark, so changed plugs and wires, pulled the V.
3. Bench tested injectors (homemade tester) and replaced lines and orings before reassembly.
4 Vacuum was all over, but when it was idling bad and surging was 0-10.
5. Greg, thanks.


This evening I checked spark on left bank, spark good. Already determined injectors good. Started car, ran bad. Took Greg's advice. One of the rods was slightly bent. Loosened the nuts and the car started running much better. Still not right.
Now the idle is surging and accelerating on its own, up to 1500. Sounds like a vacuum leak under the left manifold. I need to look at the line that goes to the dizzy cap.
Idle screw on air valve had no effect, suspect it.
Vacuum currently at 9-10 at idle, 15 when it accelerated to 1500.
Getting closer, so--
New question--when it was running decent, the left air horn was sucking pretty good air, the right air horn did not feel like it was pulling at all. Is this normal? I know there is a balance tube, but I expected both horns to pull somewhat equal air.


Thanks in advance

 

im gonna be uploading some videos here that will hopefully help you. my Jag surged from 10in/hg to 0 when i got it.

 

alright heres the video. my 1985 XJS broke a timing chain tensioner/dampner. absolutely nothing i did to it made it run better and most things made it run worse. i didnt discover the broken tensioner until i pulled the valvecovers off and realized the drivers side cam had a lot of chain slop. pulled the timing cover and the tensioner/dampner was busted into chunks.

https://www.youtube.com/watch?v=eaIC...ature=youtu.be

 

Are the throttles synchronized @ fully closed position and both throttle blades set to .002" gap when closed? If one throttle is slightly open the engine goes a little nuts.


Are the bolts that hold the air filter housings to the throttle body in place and tight. Big air leak if not, and high idle



Normal !

Cheers
DD

 

This last problem is almost certainly an AAV stuck open. The ECU will cut the injectors at 1400 rpm on a trailing throttle (so you do not accelerate/burn extra fuel when decelerating). As soon as the revs fall below 1400 the ECU starts up the injectors again. If the AAV (the thing into which the idle speed adjustment bolt goes, bolted onto the US driver's side water manifold at the drivers end of the engine) is stuck open, then your symptoms are exactly what happens.

Unbolt the AAV and try to unstick it (the Great Palm's book has suggestions). If that does not work, either buy a new one (quite dear) or you can just blank off the tube from it that goes into the manifold directly and forget about it. The other tube that goes directly into the airbox I am pretty sure you can leave alone, as it is outside the throttle butterfly. If you do also blank this one off, as you have a Lucas ignition car, you MUST rig up a place for the pipe from the top of the dizzy to go into the airbox. This is to extract fumes from the dizzy and thus prevent it exploding!

Greg

 

the AAV wouldnt explain the absurdly low vacuum pressures. should be in the 15-20 range when its surging like that

 

I would agree except, if I understand correctly, the 1500 rpm/idle surge problem cropped up only after messing with the throttle rods!

Cheers
DD

 

Quiet right Doug. The symptoms could be caused by the throttles being adjusted 'open' while the capstan TPS remains 'closed' . But as the idle screw is completely closed, my cash is still on the AAV! Place your bets!

Greg

 

The OP said it as "currently at 9-10 at idle, 15 when it accelerated to 1500."

Greg

 

so hes in the 9-15 range when its surging. not good. thats definitely not the kind of numbers an engine should be pulling at those RPM's

 

Doug is right, the almost decent idle came after the throttle pod was wiggled. The surging came after it warmed up. Can someone explain the exact way to set the throttle plates? I am not understanding, or is there a video out there. There is little slack in the throttle cable, and one of the throttle rods has a slight bend in it. Anyway, have straight and bent feeler gauges, just need directions, and sequence to adjust it all.
Thanks