Still trying to diagnose why my car won't idle great/ cut out when braking.
At idle does 10inhg of vac sound pretty low?
Still trying to diagnose why my car won't idle great/ cut out when braking.
At idle does 10inhg of vac sound pretty low?
That's fine, I think mines about the same
Easy test, if you clamp the brake servo pipe and try it then( bear in mind that you will have no vacuum assistance on your brakes so they will be very hard to press and not work very well) If it doesnt cut out then theres a problem with the servo/pipework, if it does cut out id say check engine movement, engine earths, or king lead being stretched?
Originally Posted by Tony Walker
Just tried, doesn't make any difference sadly.
The engine even when car stationary does not idle properly ( but doesnt cut out ), when trying to drive in traffic for example in 2nd gear - the engine is constantly stuttering / rocking and it makes it jump out of gear. I doubt many people could tolerate it, but i am used to a honda crx with no interior/ sound deading / rose joints - motorway driving with no stereo. But i am hardcore when it comes to that
On throttle and on boost there are no issues at all
Pressing the brakes when moving kills it though.
Not sure what a king lead is ?
Idle , when stationary, is constantly jumping from say 700 to 1300 non stop, popping sounds from exhaust too...
I think it might be an idea to tighten inlet manifold bolts etc, but i have no clue how to get the shield off ( under the carb ) its a lot bigger than on a 5
LAMBDA AT 1.8 at idle ( 25:1 afr )!!! I think that is extremely lean
Last edited by xchipx; 16-10-2010 at 16:32.
king lead is the main lead going to the dizzy cap
mine has nearly 20 inches
mine used to be nearly 20 too but i didnt want to say cause i havent driven it in a year so i could of been wrong lol.
have you got the small resticter in the breather system.if missing this can cause prolems
it won't be that lean as it won't run at anywhere near that.
mine sits at 15 constantly at idle mate i run the cup breather mod with one way valve removed.
mine runs at -10 psi. I've always thought it was too low. Am i right? dont understand why.i reckon somthin is wrong
Last edited by Slim; 17-10-2010 at 17:11.
10 psi is near as dammit 20in mercurymine runs at -10 psi. I've always thought it was too low. Am i right? dont understand why.
Bad vaccuum is to do with valves and incorrect valve timing.check the timing is right pal
pardon?? are you sayin -10psi is ok? (im reading this from the boost gauge right?)
Last edited by Slim; 17-10-2010 at 18:00.
you mean cam timing? is this easily fixed?
My problem just came on gradually , did not mess arund with any timing or anything like that so i cant see whats causing probs
Do you have a dump valve fitted? The diapham in it can split and cause a air leak?!
I do but that would only affect throttle/wot
No....
Certainly worth checking
did you get this sorted mark? im having the same problem, any help would be great
dumpvalve doesnt just affect at wot, ur right in thinking its not after the throttle blade so shouldnt affect it but.... if the diagphragm is split it draws air up the vaccum pipe connecting it to the carb which is after the throttle blade and will affect idle and vacuum on closed throttle.
mine has nearly 20 inchesAll the C1j's ive had pulled nearly 20 inches. Check your manifold and pipework for leaks.
my f7p is about 20inches on idle also with a 14.6 afr reading sitting between 950-1000rpm
Also depends upon which cam (ie, how hot) you have in situ.
heres my boost gauge on idle my car is running rough on idle and when i brake to stop it cuts out, can someone take a look at the pic does it look like the right vac?
think i may have an air leak
You might just have crap in your idle jet in the carb, give that a clean first and see how it runs.
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