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Again: random stalling - hose at throttle body not connected
Hello, my newly acquired early XJR (late 1997) is affected by the known random stalling at low speeds and especially when I do not accelerate and roll downhill in sliding mode. Whether action S-514 was done is not apparent from the documents - need to check this with my dealer.
Today I cleaned the throttle and all contacts and I have seen that the hose on the black cap is not connected. I understand that the throttle valve on the early XJR models is vacuum controlled. But I have no idea what this hose is responsible for.
Who can tell me or show me on a picture where the hose is connected? Since it is quite short, it can only be in the immediate area of the throttle body, right? Or is there another solution for the random stalling issue and this hose has nothing to do with it?
That hose and black canister is for the cruise control. For the time being, don’t concern yourself with it and focus on the stalling situation. Have the secondary timing chain tensioners been done? What have you done thus far to remedy your situation besides cleaning the TB? How many miles are on the car?
Do you have a scanner to display live data for the long and short fuel trims?
Hello and thx, my early XJR has no cruise control - only the Sport-Mode switch under the J-Gate. As stated by the seller, the chains and tensioners should have been replaced, need to check this also. Absolutely no rattling etc., the car drives perfectly, smooth idle, very good power, nothing beside the stalling. The car has nearly 100000miles (157000km) on the clock with complete service book (Jag dealer until 80000km). Unfortunately I have no live data scanner. Today I also checked both the full- and part-load breather - nothing clogged, no oil, all perfect.
Interesting to see it not have CC but yet have the canister on the TB. It’s my understanding about the TB that the vacuum canister was chrome when it rolled off the assembly line and when the recall was performed, the vacuum canister was black so it’s quite possible that it’s already been done. However, even if your TB was/is the original that the recall has long since expired being 25 years old. Cleaning the TB was a good first step. Is the air filter clean? I would check the underside of the air intake bellows for cracks as the plastic is thin there and mixed with 25 years and 100k miles of heat from the exhaust manifold is prone to failure. If the air intake seems good, I would check the charging system voltage at the battery and should be 14.2 volts with it idling and no loads on. If that seems good, maybe do a hard reset and see what that does for the car.
I have only seen 'CHROME' vacuum actuators on the 1997MY XK8 for the first few thousand cars. The sedans came about in 1998MY and never saw one on them?(in North America anyway)
Wished I had saved a throttle body from that era and had a 'chrome' actuator to 'show-off' as original on some AJ26 equipped car.
Update: Although I`m still interested where this hose from the black canister belongs at a car without CC, in the meantime I have ordered the latest version of an used AJ26 throttlebody (C2A1470). As it was only about 100 US-Dollar I will give it a try after christmas. Thx so far!
But the TB in your link is not the latest/revised AJ26 version - that should be C2A1470. You can recognize this version: they have a sticker with an "eye" and a "book" with JJM **30-99. That means you should check the documents, as this latest version must not be cleaned due to a special coating inside. Like in this picture:
Update: today I replaced the old throttle body with an used one that matched the latest revised version for the AJ26 (C2A1470) at a friend's house about 60km away. Return trip on the highway up to 160km/h due to heavy rain: everything ok, no failures , no stalling. Fingers crossed.
Again: random stalling - hose at throttle body not connected
I understand that the throttle valve on the early XJR models is vacuum controlled. But I have no idea what this hose is responsible for.
