Idle issues..

[graham]

Another slight prob, can't get her to idle below 1500rpm+, tried different ISCV and TPS made no difference. I'm using piper cams which is all new to me, can cams raise the idle like this? If I block the ISCV and the screw on the TB is in full it's down to 1100ish. It's the same hot and cold.:?::?::?:

 

[Chet T16]

Air leak?

 

[graham]

Trying to rule that out now and try another TB too, but can the cams mess with the idle?
Your probably right coz i can block near every hole on the inlet and it's not cutting out...

 

[graham]

Yea it's a leak.. My Da sprayed carb cleaner around the manifold and the revs dropped when it hit the leak. Simple but effective. So now I'm in the middle of taking da manifold off... yeaah!!!...:twisted::twisted:

 

[Chris H]

cams can affect the idle but only make it lumpy and horrible, not raise the speed.

I'd say its an air leak somewhere. You got the servo pipe on?

 

[Chet T16]

Thats teh job

 

[graham]

Leak is fixed now but it didn't totally solve it, the ISCV seems to be not closing enough and when you rev it dosen't return to idle quick enough. It's running fine with no ISCV and the manifold blocked, how would this work full time?
TBH if I could afford it at the mo I'd scrap the lot and use twin 40s...

 

[ashley partington]

sounds like you got a leak and it sound be runing around 850-950rpm

 

[Chet T16]

No iscv might affect it when its cold.

If the TPS isn't reading right then there will be no idle control. It needs to read below 5% with closed throttle. Thats not exactly helpful without a way to read it

 

[graham]

Think I saw TPS settings that could be checked with a multimeter somewhere, might try that if I can find them.

 

[Chet T16]

I got out my multimeter a while back to get the voltages but it turns out theres something wrong with the cabby one!

 

[graham]

I found the settings and set it by the 2 outer wires as close as I could. Sounded fine then idling at 1000/1100 which I could live with but I took it for a spin up the road and when I got back it was at 2000rpm. Switched it off and on again and then it was back to 1000/1100:?. I found out the clutch ratchet is scrap too...

Plenty of go in it though

 

[The T.I.B.]

I found the settings and set it by the 2 outer wires as close as I could. Sounded fine then idling at 1000/1100 which I could live with but I took it for a spin up the road and when I got back it was at 2000rpm. Switched it off and on again and then it was back to 1000/1100:?. I found out the clutch ratchet is scrap too...

Plenty of go in it though

That could be the road speed sensor if it sticks on 2000rpm after you drive it.
The sensor is part of the speedo cable and attaches behind the dials on the dashboard.

 

[Chet T16]

Where'd you get the settings?

 

[Chris H]

so its idleing ok with the icv totally blocked off? I'm surprised at that tbh.

 

[graham]

ISCV connected now but is was fine when hot without it. What difference does it make anyway? Carbed cars went fine without ISCVs for years. A simple choke cable would do.. This is a 16yr old car and it has way to many sensors and controllers for what it is. Glad I don't have a new car...
I'll try the speed sensor, after the long weekend though...

 

[Chris H]

carbs has air bypassign the throttle plates and idle fuel slots.

The injected cars don't have any air bypassing the throttle plate apart from via the breathers and the tiny amount by the plate. The plate should only just pass enough to get it idling about 800rpm hot.

The icv is active all the time to stabilise the idle.

Anyway get another icv, if you tap it with a screwdriver you may find the speed drops

 

[graham]

Thanks Chris, hopefully I'll have more motivation come Tuesday and get it sorted once and for all.

Chet, here's the settings I saved last time I came across them.

red - yellow 5.78kohms 4.65V
red - green 2.01kohms 0.28V
yellow - green 4.27kohms 4.96V