High Idle speed Suggestions
11-11-2010, 10:42 AM
#76
Rennlist Member
So the idle came down............not perfect but it did come down. Does the spanner operate the ISV?
Interested to see how the return journey home affects idle speed and the borrowed LH.
Interested to see how the return journey home affects idle speed and the borrowed LH.
11-11-2010, 12:51 PM
#77
Rennlist Member
Yes, Steve went through all the Actuator tests, inclding verifying that the ISV was cycled correctly. He also did idle adaptation twice, each time it appeared to complete correctly, even though the idle speed wasn't correct at the end.
He is going to drive the car for more miles, maybe further O2 adaptation will help some more.
He doen't have the loaner LH ECU yet.
He is going to drive the car for more miles, maybe further O2 adaptation will help some more.
He doen't have the loaner LH ECU yet.
11-11-2010, 02:00 PM
#79
Instructor
Thread Starter
Drove another 10 mles ( 20 miles total), idle is still 900rpm. This is progress though because it has never been different from 1100rpm. Now it is 800 cold, 900 hot and 700 in drive. Good point re actual rpm, is there an easy way to check ? At 1100rpm , engine 'sounds fast' ie it doesnt sound anywhere near an idle speed. I will try it tomorrow and if no change then take up Johns offer of the loan of the LH/EKZ ECU's. At least it eliminates them from the equation. On the positive side the car drives like a dream since the MAF rebuild, instant acceleration and feels like a different car
11-11-2010, 02:16 PM
#80
Rennlist Member
Good to hear its running that much better.
The tach signal comes from one of the ignition coils. As its only taken from one that fires 4 cylinders it goes through some multiplier to get a 8 cylinder reference. Perhaps John can point to where you could verify the true rev. signal.
The tach signal comes from one of the ignition coils. As its only taken from one that fires 4 cylinders it goes through some multiplier to get a 8 cylinder reference. Perhaps John can point to where you could verify the true rev. signal.
11-11-2010, 02:21 PM
#81
Instructor
Thread Starter
Malcolm, thanks it would be worth getting an actual value rather than rely on the tacho. I feel like I am progressing by eliminating elements like MAF, ECU's etc. Getting an absolute rpm would also be helpful. Would hate to try and chase down a problem that didnt exist!
11-11-2010, 03:31 PM
#84
Malcolm, thanks it would be worth getting an actual value rather than rely on the tacho. I feel like I am progressing by eliminating elements like MAF, ECU's etc. Getting an absolute rpm would also be helpful. Would hate to try and chase down a problem that didnt exist!
https://rennlist.com/forums/6583586-post41.html
11-11-2010, 03:50 PM
#85
Instructor
Thread Starter
Ted, wow thats like 40% difference between actual and displayed, although my idle 'sounded high' at a displayed 1100rpm. It sounds much better now at a displayed 900rpm. I am going to check actual though as is have never baselined the idle speed, only relied on my ear and the tacho.
Timing light with tacho sounds like elegant way of measuring the speed.
Timing light with tacho sounds like elegant way of measuring the speed.
11-11-2010, 03:57 PM
#86
Racer
Steve, your car is a MY 91, so it has a digital dash. You can enable diagnostic mode on the dash (a connection on the 19pin diag socket is sufficient) and enter the diag-sensor menu, skip until oil pressure passes and next is the digital rpm. That should be in line with the analoge gauge. Rpm is taken from the speed sensor, and processed by the Ezk for further use, not from the ignition.
Assuming your rpm is actually 900 rpm or 1100rpm, which is just too much: what happens when you disconnect the battery and wait a moment, then reconnect and start. Is it immediately 900/1100 rpm or does it start at 675rpm and gradually climb up? The latter is what I always see when airleaks exist. Also, typically, doing a idle adjust using a diag tool makes it either fail or end up at very high rpm. Yours seems to be ok with that...... so maybe it is just something else.
Did you ever swap the Ezk?
One more simple option before selling the car: remove the kickdown relay and see what that brings. The speed signal is routed to the kickdown relay and I've seen the relay corrupt the signal.
regards
Assuming your rpm is actually 900 rpm or 1100rpm, which is just too much: what happens when you disconnect the battery and wait a moment, then reconnect and start. Is it immediately 900/1100 rpm or does it start at 675rpm and gradually climb up? The latter is what I always see when airleaks exist. Also, typically, doing a idle adjust using a diag tool makes it either fail or end up at very high rpm. Yours seems to be ok with that...... so maybe it is just something else.
Did you ever swap the Ezk?
One more simple option before selling the car: remove the kickdown relay and see what that brings. The speed signal is routed to the kickdown relay and I've seen the relay corrupt the signal.
regards
11-11-2010, 04:08 PM
#87
Instructor
Thread Starter
Theo, yes it does have digital dash, will investigate how to display digital rpm, that is very helpful. Until today, the idle has always been consistent ie when cold its 800rpm, gradually rising to 1100rpm ( linearly, in line with temp gauge). Have been having help from forum and yesterday ran diagnostic with borrowed 'spanner'. Initially had no effect but after drivng 20 miles idle dropped to 900rpm at hot. So currently car runs at 800 rpm cold, rising to 900 rpm hot and 700 rpm in drive
11-11-2010, 04:11 PM
#88
Instructor
Thread Starter
Theo, just reread your note. Idle has never been at 675rpm. Closest is 800rpm at cold. When hot it starts and immediately settles at 1100rpm (900rpm from today). Will check out kickdown relay tomorrow
