Warm up regulator-----Pointless???

[Bjork]

Hi guys.

Got something I can't get my head round and hope you can help.  

On cold start up my 16v kr engine runs rough. It starts first time and idles lovely bu is very lumpy under load untill it gets up to temp then it's all sweet again.

I've disconnected the WUR and that seems to have helped loads.

What I don't get is how can disconnecting it make cold running better when it's there to aid it?

Also, what downside is there to me disconnecting the WUR??? (low mpg, bad for engine, etc???)



Please help me get my head round this as I'm starting to think I'm going a bit mad.  

[rubjonny]

what you have done is slow down the time it takes for the mixture to lean out to the hot running setting, which suggests the base mixture needs to be adjusted and/or you have an air leak. The electrical connection is a heater which brings the k-jet mixture 'off choke' quicker, the same effect will eventually be achieved by engine heat but it takes longer.

This is assuming the wur is actually working properly, it could just be buggered!  Only way to know if the WUR is ok is to get the control pressure checked from cold to hot, and also check the system pressure to make sure thats ok, if the system pressure is off it'll throw everything else out too.  Other option is to assume the wur is fine and get the CO checked once you are 100% sure there are no vac leaks, and the timing is all spot on. KRs run well at 2%

[Bjork]

Cheers rubjonny.

co setting is fine and timing was done after new cam chain + canmbelt + tensioner.

Haven't had the system pressure checked, is it an expensive test?

Main worry is if I'm doing damage by having it disconnected.

[rubjonny]

ideally find a place that has good knowledge of the k-jet system, its easy to mess it up. the gauges themselves can be had for under £100, or you could try makign your own, but make sure your fittings are good as its got to cope with over 5 bar!

[Bjork]

Don't worry, I won't attemp the test myself. 

But will I be harming the engine by having the WUR disconnected?

[rubjonny]

nah be fine, worst case is it'll be a bit richer during the warm up phase but no harm in that unless its proper drowning it, and if it was you would certainly notice it smelling rich and/or running like arse!

[Diamond Hell]

But will I be harming the engine by having the WUR disconnected?

If you do lots of short journeys there's a chance with the engine running too rich you'll get 'bore wash' - too much fuel sloshing about glazes the bores and means the seal on the piston is shagged out - you lose compression and power. 

It's there for a reason.  If your K-Jet system isn't running right, it's because it's old and knackered.

I'd check the 5th injector for correct function, before pointing the finger at the WUR, in fact, check all the cold start junk nailed on to the engine - at this point your problem is a cold-start issue, not a WUR issue.

[Bjork]

Cheers. I'll look into it.

Thought the cold start valve only fired for a few seconds on start up though?

Seems to be running fine with the wur unplugged.

Was smelling really rich beforehand but now seems better somehow.

[dan7]

Is the 8v WUR the same as the 16v one? K-jets.

[Mk2George]

Mine runs lumpy till its warm too and has a definate flat spot till it warms up. How do I test the WUR (And I take it this is the thing with the wire connector on the end of the fuel rail yes?)

Cheers