Checking the Purge valve is search of the Code 26 and hunting=============================================================
The cover that goes over Carbon canister, Purge valve plus two outher
“assorted valves” which sits in the left fender well, is fixed on with
steel screws in rubber grommets. Screws had siezed in threads and when
you turn it the rubber goes round and round. No way to get behind it.
Had to take the whole front valance off!
Anyway, short hose from purge valve to canister was very cracked (yes?).
I disconnected hose on other side of purge valve (ie inlet manifold
side) and plugged hose. Started engine and it still hunted/surged like
crazy (no!).
Whilst I was there, I checked valve opened and closed (engine off=open,
engine on=closed).
Also re-checked other end of hose and noticed I could turn hose clip
(well you can’t actually see it). Took hose off inlet and chopped 1/2
inch off and replaced. Tightned clamp but was still spinning. Then…
Damn thing came off in my hand! Pipe has come out of casting. Looks like
it supposed to be shrink or interference fit.
Replaced with a big gob of silicon to hold it in. Fit was snug anyway so
I knew this failure was fairly incidental.
The hunting is really bad now. I notice is pulling at low road speeds.
Idle all over the place. ENgine speed drops immediately after start to
500 rpm (near stall) then shoots up. Then down… then up…
The problem is getting worse but still has times of near normal
operation.
Tried to get fuel pressure gauge today and failed. Gonna get my meter
out and check throttle pot and O2.
Suspect my leak (if indeed this really is a leak) is EGR/inlet block or
inlet manifold gasket. Inlet gasket looks good all round but you can’t
see 100%. EGR was cleaned out by me before problem. I can’t see it too
well and I might have messed gasket up re-fitting it back on.
Got propane torch today so we’ll see.
Think I’ve only got about 26 items left to check.
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1990 XJ40 4.0L Sovereign 125K
1995 Ford Winstar LX ()
197? 25cc Weed whacker (ate stone & threw rod RIP maybe)