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Topic: Tickover revs fluctuating (Read 1216 times) |
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Jonnycab
Senior Member
Former owner of 2.3 Ultima Facelift saloon
Posts: 3900
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Tickover revs fluctuating
« on: Sep 12th, 2008, 1:16am » |
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Not a problem I've had before, so hopefully someone can give me a clue 
On the wifes 2.3 estate, just after start up, the tickover will start to fluctuate between the normal 850 revs to about 1100 revs. It only happens for a minute or two when the engine is cold. When starting it from warm it's fine.
I've plugged my handheld scanner in & it's not come up with any fault codes. Checked for any air leaks in the inlet manifold & pipework, but none can be found & tried a spare IACV, which made no difference.
I'm thinking possibly a problem (when cold) with the fuel pressure regulator ? 
I've not really gone to town on trying to find out what is causing the surging revs, as it's not really a big problem, but if anyone has any suggestions as to the reason, it would be nice to sort it out  .......
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Snoopy
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Very old.BAD tempered and missing friends.
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Re: Tickover revs fluctuating
« Reply #1 on: Sep 12th, 2008, 7:34am » |
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This sort of phenomenun seems to be IACV related from past history . Also make sure the inside of the air intake where the butterfly is , is clean and there is no build up of carbon, but I do advise caution as I undestand there is a coating on the inside which helps with air turbulance etc , BUT I don't know exactly what is there, but i am sure someone will soon be along to correct me and tell you correctly.
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Simmo
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Re: Tickover revs fluctuating
« Reply #2 on: Sep 12th, 2008, 7:44am » |
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Jon, Snoopy is correct in that the IACV is the first suspect. The carbs do have a sticker inside the intake saying not to clean the interior as it is specially coated. However it is possible to clean the edges of the butterfly flap with a cotton bud or similar soaked in carb cleaner which will remove any carbon build up. Mike.
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Tompion
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1997 2.3 Ultima estate.
Posts: 2918
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Re: Tickover revs fluctuating
« Reply #3 on: Sep 12th, 2008, 8:57am » |
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on Sep 12th, 2008, 7:44am, Simmo wrote:| Jon, The carbs do have a sticker inside the intake saying not to clean the interior as it is specially coated. Mike. |
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Don't spend too long looking for the carb
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Highlander
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13 Scorpios, XR4x4, Suzuki SJ413 for off road :)
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Re: Tickover revs fluctuating
« Reply #4 on: Sep 12th, 2008, 11:43am » |
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Its Simmo, we have to make allowances for him, some days he wakes up in the 1930's
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on Oct 17th, 2011, 12:35pm, Simmo wrote:I give up !  Too much for an old boy!  |
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Jonnycab
Senior Member
Former owner of 2.3 Ultima Facelift saloon
Posts: 3900
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Re: Tickover revs fluctuating
« Reply #5 on: Sep 12th, 2008, 12:13pm » |
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I've tried a different IACV & it made no difference. I did also (forgot to mention) clean the throttle & butterfly flap but this still has made no difference
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gozz
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Re: Tickover revs fluctuating
« Reply #6 on: Sep 12th, 2008, 8:34pm » |
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Oi Highlander !
At least old Simmo wakes up 
GOZZ
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Simmo
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Re: Tickover revs fluctuating
« Reply #7 on: Sep 12th, 2008, 9:33pm » |
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Now now lads !!. Thank you Gozz.
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Jonnycab
Senior Member
Former owner of 2.3 Ultima Facelift saloon
Posts: 3900
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Re: Tickover revs fluctuating
« Reply #8 on: Sep 14th, 2008, 1:36am » |
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Oi !!.....stop hijacking my post !! 
Constructive answers only please
P.S....I don't think that the special (sticky) coating behind the butterfly flap in the throttle is there to aid air turbulence
From what I've read, it's supposedly there to trap any small nasties from entering the manifold
This 'special coating' can be completely removed with no detrimental affects to the tickover or running of the Scorp
The above pic is of the throttle that I cleaned out & put in my Scorp & it still ran fine 
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Jonnycab
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Former owner of 2.3 Ultima Facelift saloon
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Re: Tickover revs fluctuating
« Reply #9 on: Sep 23rd, 2008, 12:48pm » |
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I had another little tinker about with the wifes Scorp the other day & discovered that if I pull off the vacuum pipe that goes from the throttle to the fuel pressure regulator at the throttle end, then the revs even out, although a little high.
There seems to be plenty of suction from the throttle body & the vacuum pipe has no splits in it, so it is leading me to believe that it may well be a problem with the fuel pressure regulator
I've got a good spare, so I'll fit it when I've got a moment & see what happens .....fingers crossed
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Tompion
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1997 2.3 Ultima estate.
Posts: 2918
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Re: Tickover revs fluctuating
« Reply #10 on: Sep 23rd, 2008, 4:42pm » |
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Diconnecting that hose increases the rail pressure by about half a bar at tickover.
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Jonnycab
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Former owner of 2.3 Ultima Facelift saloon
Posts: 3900
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Re: Tickover revs fluctuating
« Reply #11 on: Sep 23rd, 2008, 5:03pm » |
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on Sep 23rd, 2008, 4:42pm, Tompion wrote:| Diconnecting that hose increases the rail pressure by about half a bar at tickover. |
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Yes, I know...but it stablized the tickover at the higher revs......do you think I'm barking up the wrong tree ?
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Tompion
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1997 2.3 Ultima estate.
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Re: Tickover revs fluctuating
« Reply #12 on: Sep 23rd, 2008, 7:18pm » |
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Do you mean the revs are higher with the hole open on the manifold or with the hole plugged? I think mine revs higher with the hole open with a warm engine, no difference with the hole plugged.
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Jonnycab
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Former owner of 2.3 Ultima Facelift saloon
Posts: 3900
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Re: Tickover revs fluctuating
« Reply #13 on: Sep 24th, 2008, 12:07am » |
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Yep, the tickover is higher & constant with the hole open. Plug the hole & the revs obviously drop but tickover hunts up & down
Once the engine is warm then car ticks over fine at a constant 850 rpm
I know the problem points toward the IACV, but in this case that isn't the problem as I know the spare IACV is good because I've tried it on my Scorp
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TRACEYS_LIMO
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Re: Tickover revs fluctuating
« Reply #14 on: Sep 26th, 2008, 8:10pm » |
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hi jc have you checked or swapped your maf
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Jonnycab
Senior Member
Former owner of 2.3 Ultima Facelift saloon
Posts: 3900
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Re: Tickover revs fluctuating
« Reply #15 on: Sep 27th, 2008, 3:21am » |
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No, haven't checked or swapped the MAF.....come to think of it, I haven't tried cleaning it yet either
I'll give it a clean & if no difference I'll swap it over.......got a spare one of those too
Thanks for the suggestion TL
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