When my mini (1992 cooper injection) is just idle, the engine starts "pulsing". I think thats the best way to describe it.
The worrying thing is that this happened to my brother's Fiat about a week before the head gasket went. :saywhat: :erm:
Does anyone have ANY suggestions on what it could be, or what I can do? I'd really like to catch it before it's too late!!
ANY help appreciated. Cheers.
PLEASE HELP! - Erratic Idling
Started by
gsms
, Oct 16 2005 12:22 PM
4 replies to this topic
#1
Posted 16 October 2005 - 12:22 PM
#2
Posted 16 October 2005 - 12:24 PM
Lambda sensor
Temp sensor - causing overfueling if ECU thinks engine is cold, therefore revs are increased to warm it up. (did this on my 306)
Oxygen / air sensor
I would have it checked out on a diag machine before i worry about head etc.
Air leaks etc also possible causes.
Temp sensor - causing overfueling if ECU thinks engine is cold, therefore revs are increased to warm it up. (did this on my 306)
Oxygen / air sensor
I would have it checked out on a diag machine before i worry about head etc.
Air leaks etc also possible causes.
#3
Posted 16 October 2005 - 03:12 PM
The pulsing is the stepper motor, or, may also be due to the ECU constantly changing the ignition advance by large amounts, or , a combination of both, all to try and keep the idle speed at 850.
Things to check and replace in this order
Calibrate (Index) the throttle and cable
Check all the thin black red and yellow vacuum lines, particularly the two that come off the back of the manifold. These have a habit of splitting. ensure there is no chance of a leak. * EDIT (Make sure you check the ones on the charcoal canister under the right wing)This is on carb models and does not apply to the SPi *. Ensure there is no fuel or oil in the lines to the ECU, blow them through. Infact, dont check the fittings/ elbows on the back of the manifold, replace them. :cheese:
Check all breather lines are clear and no leaks, agian check the charcoal canister.
Change the Lambda sensor
Change the fuel filter
Other common faults that can exist are faulty stepper motor, Shorted out PTC heater, Duff MAP sensor in the ECU. Check those above first as going deeper requires a Diagnostic unit like the one i've got http://cgi.ebay.co.u...1QQcmdZViewItem This is the most basic of basic tools but the most affordable
Things to check and replace in this order
Calibrate (Index) the throttle and cable
Check all the thin black red and yellow vacuum lines, particularly the two that come off the back of the manifold. These have a habit of splitting. ensure there is no chance of a leak. * EDIT (Make sure you check the ones on the charcoal canister under the right wing)This is on carb models and does not apply to the SPi *. Ensure there is no fuel or oil in the lines to the ECU, blow them through. Infact, dont check the fittings/ elbows on the back of the manifold, replace them. :cheese:
Check all breather lines are clear and no leaks, agian check the charcoal canister.
Change the Lambda sensor
Change the fuel filter
Other common faults that can exist are faulty stepper motor, Shorted out PTC heater, Duff MAP sensor in the ECU. Check those above first as going deeper requires a Diagnostic unit like the one i've got http://cgi.ebay.co.u...1QQcmdZViewItem This is the most basic of basic tools but the most affordable
#4
Posted 16 October 2005 - 03:24 PM
Just to add to all the suggestions, a cheap and easy way to see if there is aleak between your intake manifold and all breather pipes, fill a squirty bottle up with water and washing up liquid and spray it where the manifold gaskets are when the engine is warm and running also try spraying around the vacuum pipes. If the engine settles the is a leak and the gaskets/pipes will need replacing.
Worth a try!
Worth a try!
#5
Posted 16 October 2005 - 05:18 PM
Ok, thanks a LOT for all the help everyone.
I'll give some of those things a try.
Cheers!
I'll give some of those things a try.
Cheers!
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