Well the 85 Cat has been garaged for 2 years now with not a whole lot of time to spend on it. I do start it once every other week just to keep the battery some what strong. It has been running weak with a very low and weak idle. Hoping to find someone who really knows these cars to get it up and running right again. Your help would be appreciated.
Thanks JR
1985 Jaguar XJ6
Maybe check around for a local Jag Club. The members would have some answers for you and perhaps even offer some hands on help getting yours going.
Phillip
Can you drive it? Whatever you do let it get hot at least a few times a year. Startup and idle is bad, nothing gets hot, the spark plugs soot up, the whole engine soots up, the exhaust rusts from all the condensation, the oil gets thin with gas over time, battery conditioners are what - 5 bucks?
If I were you I’d
take the battery out,
charge it from time to time,
remove the gas or run the car until empty because the gas will get bad,
stop with the ‘charge runs’ because they are a bad idea,
and remove and clean the spark plugs (Torch, get new ones or sand blast, less recommended).
And of course these cars like to be moving a little from time to time.
Give it the ‘italian tuneup’ if possible and if it helped doing the above steps. For the spark plugs you don’t need a mechanic, just the right wrench and five minutes to have a look; don’t overtighten of course…
And then check for a club, and stay here for questions. Welcome back I should say?
David
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It’s probably something you can easily fix yourself, JR…
Frank
xj6 85 Sov Europe (UK/NZ)
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I should of made it clear that when I start it I let it run until it gets up to normal operating temperature. I do put a charge on the battery every once in a while just to keep it fresh as well. I have added a gas additive to keep the gas good as well. Plugs, wire, rotor, and cap have all been replaced. Starts then it wants to die. It will then re-start and idle at around 500-700 and runs lousy. When revved up it runs ok it just idles way to low and has no get up and go. Two mechanics have looked at it and have not figured it out.
I should of made it clear that when I start it I let it run until it gets up to normal operating temperature. I do put a charge on the battery every once in a while just to keep it fresh as well. I have added a gas additive to keep the gas good as well. Plugs, wire, rotor, and cap have all been replaced. Starts then it wants to die. It will then re-start and idle at around 500-700 and runs lousy. When revved up it runs ok it just idles way to low and has no get up and go. Two mechanics have looked at it and have not figured it out.
You may a fuel starvation problem. Have you looked at the fuel filter? If that is all gunked-up you will need to address a dirty/rusty fuel system, starting with the gas tanks and ending with the injectors.
Phillip
Or an injector down as it does rev up but runs bad? Down, or clogged due to rust.
Try pulling connectors at the injectors one after another; worth a shot.
If it starts good but runs lousy check for vacuum leaks also, with brake cleaner or similar. Hungry mice in your shed? Hose fallen off?
Can you pinpoint an event when it started (probably not, and surely you found all the obvious mistakes do not apply - no fuel, obstructed intake, loose battery clamp and these things)
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Have you driven the car to assess the ‘no get up and go’ JR - or is it a guess based on the bad idling…?
Is there any idle/starting difference cold and warmed up? There should be a substantial difference in rpms hot (800 rpms or so) and cold (1200+ or so ) due to the action of the AAV.
If the engine responds normally to the gas pedal, reving up. there is nothing wrong with fuel supply. The bad/low idle may relate to AAV failing or dirt build-up in the throttle - you can disconnect the air duct and clean the throttle body…
You can inspect the AAV by disconnecting it’s top air hose and look at the slide position. It should be about half open when cold - and closed with the engine hot. If slide is closed while cold; difficult starting and low/bad idling ensues. Adding that if hot idle has been set with a faulty AAV - idle anomalies will ensue.
There also may be an issue with the coolant temps sensor - disconnect it briefly, hot and cold to se what happens…? You may have a misfiring plug - or indeed high tension going astray due to dampness. Open the hood in the dark, stat the engine and look for telltale arcing - wiping high tension parts with a dry cloth may help.
You don’t mention if problems are recent, nor what the mechanics actually did…?
One problem is that the xk will behave perfectly at higher revs, with faults mentioned above - and even with rather bad faults while idling like s… in either cases. For serious faults a compression test is required as a first step - any mechanic can do that…
Frank
xj6 85 Sov Europe (UK/NZ)
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There is a big difference in the demands on an engine depending if it is under load or not. A quick look at a fuel filter would be a good idea as a check for debris in the system and a fuel pressure check would also be helpful to check the condition of the fuel pump. The elimination of a fuel starvation issue would be a good first step.
I agree that it’s a good idea, Phillip, but when the engine can rev up and also sustains that I’d say there is enough fuel… flow. Could the pressure regulator be stuck and deliver low pressure at idle? Just an idea…
No diff from cold to warm. Replaced coolant temp sensor not to long ago. Will check on the AAV. Can you shoot me a pic of the AAV. Just want to make sure I am looking for the right part.
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It’s unique and easily found, JR…
Look below the AFM, the AAV is bolted to the inlet manifold. Aluminium coloured, a square base, four bolts, with a sort of tower leaning away from the engine - the air hose and an electric connector…
Frank
xj6 85 Sov Europe (UK/NZ)
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Those are simple enough to test… Just remove it, put it on a flat top stove (water optional) and note whether it opens fully, and at what temp (don’t get it too hot)… Then let it cool, pop it in the freezer and see if it closes fully… Hi Frank, David Boger told me to test it this way. Do you approve?
fuel 2 yrs old? pushin it even with stabilizer and if it is ethanol fuel,.worse…if No ethanol…,still 2 yrs…,I’d siphon most of it out and replace, be sure fuel filters are refreshed, float not stuck. do easy first. Nick
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Certainly, JR1 - a flatlidded pot heating water is sort of safer. But no submersion of the AAV - it is also electrically operated…
Actually, while it should be fully closed well below engine operating temps - it is very unlikely to be fully open in the freezer. Half open when ‘cold’ is usually as good as it gets…
Testing in-car usually reveals AAV problems…
Frank
xj6 855 Sov Europe (UK/NZ)
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