posted this in the wrong section of the forum, hopefully a mod can help, but here is the url and the rundown;

https://www.jaguarforums.com/m_36342..._/tm.htm#36342

ok, so i just bought this amazing XJ6. I have all of the original paperwork on it, i am the fourth owner, and i have every receipt for every service that has ever been done to it since new up until 2004. the leather on the ionside is like new, it just needed some light conditioning. and the exterior only has a couple "bad" spots. some minor paintchips, a couple medium size rust spots (which are not visible until you open the trunk lid) and one dull spot where the sun has flaked the clear coat. it did need a battery when i bought it, so i put a red top optima in it. afterwards it started right up and i drove it home. now the only mechanical things that it needed when in bought it was a powersteering pump, a brake booster and maybe a master cylinder. other than that it seemed fine. So i gave the owner $600, and drove it home, all of three blocks away lol. i have recently learned from my mechanic friend that everything runs off of the pressure that the power steering pump (crank driven from the block? is it?). so i may not have to replace the power booster and the master cylinder. Anyways, onto my questions;

1. is that true? do i only need to replace the PS Pump? you can p[ut fluid in it, but it wont hold it, it seems to pour out. i havent put any in yet, cause it only seems like a waste of money to watch it hit the ground.

2. the master cylinder resevoir doesnt seem to be losing any fluid, yet there is tons of "dried fluid and gunk" around the lines and under/on the booster.

3. i replaced the spark plugs today to bosch +4's PT & IR. i only did this because it was starting to misfire really bad. i ordered the plug wires afterwards because it is still mis firing, and i will be picking them up in the A.M. the one thing that bothers me about the mis fire is that at idle, its not really that bad. if i put a little bit of pressure on the gas, it is fine, but if i put even a gradual pressure down on the pedal it seems to "drown" in gas and stalls out. In gear its a totally different story, if i want to back up or go foward ican only breathe on the pedal, otherwise it stalls. will changing the plug wires fix this issue, or is it my injectors? i really hope that it isnt cause i have been told that i should only get those from the dealership, and who knows how much that will set me back. and on another note about the mis-fire, the RPM gauge "bounces" around while it idles, and even while its in gear, which it didnt do when i first bought it. it functioned properly.

other than that i cant really think of anything else right now. i figured that i was getting a great deal, which i still believe i did, cause i am willing to spend $1000 - $1500 on parts for it and making it last. the engine was, in its most basic form of being done, rebuilt, in 2004. there are new pistons, rings, valves, springs, etc. the transmission was also rebuilt. torqu converter, gears, and so on.

here are some pics, enjoy. and any help on the diagnosis would be much appreciated.




i forgot to mention that a couple days after i bought it it started to misfire, but i was really low on gas and figured that because it sat for a couple months there was water in the tank, so i filled it up and put a bottle of dry gas in it and everything seemed to be fine. after driving about 150 miles after that happened, all hell seemed to break loose. i was just under a half a tank of gas and it started to mis-fire again. so i analized the situation, and realized that it wouldnt do it if i only put a little bit of pressure on the pedal. anyways, it takes forever to get to 40 MPH when doing that, but once i got to about 50 MPH, i could floor it and it wouldnt drown, and it wouldnt misfire at all. quite frankly, it would take off like a bat out of hell, like a jag is supposed to. anyways, i just thought that this might aid in a proper diagnosis.

 

I am not sure about the older cars, but 88 should be first year of XJ40. is it 6 cyl or 12cyl? I know the older timers at work are always messing with the idle control valve. Maybe someone here with more experience can help you more, but it sounds kinda like the idle valve to me. Get a 98 and I will be able to help you more.....j/k

Good luck with it.

 

the title says 1988 XJ6 and the badge on the rear also says XJ6. It is an inline 6 cylinder. chrome valve cover on the passangers side, and the fuel rail and air intake on the drivers side. all i know is that in most auto shops there are two different codes for the engine, both state 3.(whatever)Litre 6 Cylinder, but one has a 5 at the end and the other has a 6. i dont know the difference except for the fact that they gave me the spark plug wires for the 5 earlier today and they weren't the ones that i needed. i have the engine that requires the "post type" boot that attaches to the plugs in the cylinder head. otherwise i will find out by 10a eastern time whether or not that new wires and plugs fix my proiblem. and its not just the idle that worries me, its the fact that when i need to accelerate while im in gear, i can't without the car losing all power, misfiring and wanting to stall. like i said, it seems like the engine is drowning when i put my foot down on the accelerator.

BTW, is there any way to check the gap on the rotor in the Distributor cap? i looked at it today, and it seems nearly impossible because the posts for the wires is in the top part of the cap .... [headscratch]

at this point i simply just want it to be drivable, like it was a week ago when i bought it.

 

I re read your thread . So I had an '88 too .It was 3.6 liter engine.Quite reliable and powerfull too .I hope yours isn't 2.9 .I heard many nastry things on that engine .I had replaced my spark plugs w/ Champion .It also stalled once and they pulled off and cleaned the injectors and other what not things I can't remember .The problem was gone.Another thing you should replaced your fuel filter .
As to the fluctation for idling ,you should clean your throttle body as well as a gadget that sets up idling .Whenthat idle adjustergets dirt it needs to be cleaned or changed .
Also have it checked your fuel pump it may need some attention

 

ok, so i put the new wires on today and it had a hell of i time starting, so i think i may have a fual problem, cause once it did start, it was still "drowning" and stalling when pressure was applied to the pedal. i did buy a fuel filter, but cant find the old one, so i am lost as to where it is. the fuel pump and filter were replaced in 1998, i have all of the receipts for every service that has ever been done to it since new, up until 2004. i might have to clean the injectors, and the throttle body, but damn, what a pain in the *** it is to get to the TB. what is the proper procedure to clean the injectors. i know that i have to remove the fuel rail with the injectors in tact, but how do i check them??? i could put a catch can under them, but im not going to be stupid, that just deems really improper to me. any help would be appreciated.

 

You are still wide open with possiblities. Clean the crank sensor. Did you see signs of oil on the old spark plug wire boots? Do you have any code in the VCM?

 

yeah there was a little bit of oil on the old plugs and boots. i replaced the fuel filter today and its still doing the same thing. the fuel pump is priming, i can hear it when i turn the key on, but i might replaqce it as well. which hopefully shouldnt be hard because it is chasis mounted. where is the crank sensor so i can clean it? should i bother taking the throttle body off and cleaning it too? it seems like the engine is getting enough air, just not enough fuel. like i have said earlier, with a steady increase in pressure on the accelerator, it idles fine and revs without a problem. its only when you drop the pedal to the floor that it stalls. which seems like a fuel problem. i dont know, i'm begining to think that i didnt get such a great deal on this car. im willing to fix it, but i keep finding things wrong with it. like today i found a connector by the booster that had an alligator clip in it, i guess closing the circuit. and then i found the other end of the connector with a wire attached to it. i followed it and it wasnt attatched to anything, the two ends were twisted together. i have no idea what that does or how it could be effecting this issue. i also found another plug underneath the glovebox where all of the relays were; it wasnt connected to anything and i couldnt locate its other half. i also found two wires that i guess were grounding something, because that were screwed to a piece of metal by an eylet, but their ends were cut and i couldnt find what they were attached to.

i am willing to do anything and everything to get this car back to the way it came from the factory, i just need assistance in fixing the many issues that the haynes manual does not cover. does anyone have the factory repair manual in PDF format that they could post a link to?

 

I would start with a valve cover kit. This could cause all kinds of problems, particularly a misfire.

http://www.motorcarsltd.com/item.wws?sku=IN102129

The crank sensor points to the teeth on the back of the crank dampner.

 

i still have no idea where the crank sensor is. on the front of the engine, or the back?

 

what do you have against bosch? anyways, i finished installing the fuel pump today and no fix . so now its on to the valve cover gaskets and ring seals. i also cleaned the mass air-flow sensor and it seems to idle better, but its still stalling out when i press down on the accelerator..

 

I still think the leaking valve covers may be causing arching inside the spark plugs wells in the valve cover. That's why we sell ours in a kit that includes the spark plug boss seals.

I agree with not using Bosch plugs on this car. Our shop gets the best performance out of Champions plugs. (Yes, Champion plugs.) That is what Jaguar installed in the factory. We've had lots of complaints about misfires with Bosch in these vehicles.

Why I don't know. It's kind of how does popcorn pop? Who really cares? It works! Besides, it's not often you here people trying to down sell you. Champions are less expensive and installed from the factory. Who's to argue?

 

yeah i am ordering the part tonight. i hope that i dont have to replace the spark plugs to get it to run correctly, i just spent close to seven dollars a piece on the bosch plugs. but if i still end up having problems i will put the old plugs back in.

when i remove the wires to replace the seals, can i use electronic parts cleaner to clean the plugs and the boots off? also is it possible that the TPS has gone bad, because when the car is at its regular idle, before it stalls out, the rpm gauge is jumping up, irregularly. the engine isn't gaining any audible rpms, atleast not the 500+ indicated by the gauge; so couldnt that be the TPS? or could that be the crank sensor? or worse the cam sensor? [which from what i understand and know about engines, is located in the engine itself]

i guess i wont know until i replace the valve cover seals. hopefully they cure the problem.

 

Start with the known bad and see where that takes you. Good plan!

 

ok so the valve cover gaskets didnt do anything, except maybe seal up the small leak. i cleaned the plugs, put the origanls back in, and now it wont even start. it turns over, and it cranks without a problem. it may start, but it imediately stalls out. the bosch plugs that i took out, before i put the old ones back in, were solid black at the tips, so doesnt that mean that they were getting too much fuel??? what could be the problem? i have no idea

 

its finally fixed. replaced the crank sensor, the ignition amplifier, and the air filter. now it runs smoothly. finally lol

btw, which section would i find what color combinations on the radio wires mean? i pulled out the stock radio only to find that the wires are all differently colored and not really destinguished as pairs of like colors.

 

Possibly a load of meaningless old tosh but it may give you some insight? Sorry I dont seem to be able to help with the wire colours though[&:]

The 1988 to 1996? XJ40 cars had three different radios in the U.S.

- early (CB style) to 1990
- early CD version that included the woofers under the rear seat, and the later
- CD style radio that dropped the woofers under the rear seat.

The radios with the woofers under the rear seat have restrictions inside the radio that limits the audio to the door speakers to mids and highs only. The woofers get lows only.

There were a few speaker setups :

- the base model cars had 3.5 inch speakers in the doors high up
- the VDP had 4 inch speakers lower in the doors.
- the VDP also may have had the bigger 5-1/4 inch woofers under the rear seat, up from the standard 4 inch ones.

Speaker wiring is non standard. The front and back door speakers share a common (ungrounded) wire, and the system is set up so when fading to front or rear, the one speaker gets the total output power (24 watts rms).

The early (CB) style radios hold up well if kept dry, all the radios have problems getting wet from clogged drains in the climate control system.

Typical problems include solder problems on the output chips on the audio amp board (the one that has the fins), frequency display light bulbs burnt out (8 volt bulbs), missing segments on the display, buttons that don't work, and tape drive belts worn out.

The display can most times be fixed by touching up the solder at the film type connector close to the frequency display and the film connector on the main board. Sometimes the display goes bad and the liquid leaks out,or the connections to the LCD glass get rust on them from the radio getting wet.

Buttons that don't work can be the solder dots that connect things on the film on the back of the front panel, or bad button switches. Some electronics stores have the switches.

Most of these radios have adjustments on the side of the radio for the squelch and sensitivity during CB reception. Normal operation should have the radio quiet unless someone close is using a CB.

The sound of this setup can be improved quite a bit by changing out the 4 inch woofers under the rear seat to the 5-1/4 ones (DBC-10597), and changing out the very low quality door speakers to bigger and better speakers. Its possible to fit at least 4 inch speakers instead of the 3.5 inch speakers. The bigger speakers (DBC-10597) just snap in, no screws, no connector changes, look good with new grills included.

The CD style radios have problems with the frequency displays going bad, keep them dry ! They also seem to have problems blowing out parts and chips. The CD player in the trunk can be replaced by an Alpine CHM 620s, or that can be fit if you did not get one with the car.

Jim