Chimaera idle speed

Chimaera idle speed

Author
Discussion

geoff zero

Original Poster:

10 posts

38 months

Friday 5th August
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Hi everyone, I have a chimaera 500,it ticks over at around 950 rpm but I would like to reduce it, can anybody tell me how to do it please

sixor8

4,336 posts

248 months

Friday 5th August
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You realise many owners would be happy to have a stable idle speed around 950 rpm? it becomes an issue for many, including myself in the past. frown Faulty stepper motor or components in the ignition system all contribute to issues.

But anyway, it is controlled by the ECU. So it can't be altered unless you change the ECU I'd have thought. Unless anyone knows differently? scratchchin

NicBowman

478 posts

218 months

Friday 5th August
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Be happy. Nic

Classic Chim

11,724 posts

129 months

Saturday 6th August
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I think big cam = higher tickover due to bad wear rates and possible hunting which is actually normal for big big cam use but not what customers of Tvr were after as they were wanting a more sophisticated ride biggrin
Cam timing especially advanced is limited using a distributor system.

You can indeed get a tickover down to about 750 using after market ecu and coil packs or maybe a modern 123 dizzy and clever use of advanced ignition timing which makes pulling off a dream as even on tickover I can move my car around with zero throttle inputs but more difficult using the CUX and old stepper system as it’s only just reliable at 900 revs.

Times have changed so regular use is far less likely so having after market is a luxury but done well it’s well worth it for an engine that runs almost like a very modern unit and mine responded marvellously to an ecu change.
Not much faster top end but useable power everywhere and more of it and so smooth to drive but that’s on a 4.6 on smaller induction pipes so a 5.0 should respond slightly better bhp wise I’d expect smile


blitzracing

6,330 posts

200 months

Saturday 6th August
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Roverguage will tell you what the target RPM is written into the Eprom and it can be changed quite easily with a quick reprogram of the chip. It's very unlikely however unless some 14cux meddler has been in there already that it will have been changed. It's far more likely the base idle screw is too far up and letting in too much air. It's the hex screw next to the throttle plate area on the top of the plenum. Try winding it down a turn?

spitfire4v8

3,840 posts

161 months

Saturday 6th August
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Also to add .. rovergauge is a useful tool in other respects .. it will for instance give you the rpm reading at the ecu, which you can then compare to your tacho. There is no guarantee your tacho is telling you the correct rpm ..

geoff zero

Original Poster:

10 posts

38 months

Saturday 6th August
quotequote all
yeah the tickover is reading right according to rovergauge but I had a rover v8 on cards with tickover around 750 and it just sou

geoff zero

Original Poster:

10 posts

38 months

Saturday 6th August
quotequote all
yeah the tickover is reading right according to rovergauge but I had a rover v8 on carbs with tickover around 750 and it just sounded better