Glad to hear your car has found a new enthusiastic home. Plenty of good advice here on the board. I wish i could help with your erratic idle problem as I have a similar issue. When the engine is cold it idles fine, but when hot it idles at 1500rpm and then goes back to 700-750 rpm. I even replaced the AFM but it did not solve the problem.
I will try your suggestion of the temp sensors Batmobile, where are they located?
Post some pics when you get a chance and best of luck with your new purchase.
I will try your suggestion of the temp sensors Batmobile, where are they located?
I am not going to rule out the temp sensors, but these generally are not the cause of an arratic idle. I hope that with the replacement AFM, you also adjusted the CO to 1,5% with the adjustement screw on the AFM? Bear in mind that the M88/3 has a center adjustment screw in teh middle of the TB's for cyl #3 and cyl #4 that controls the idle speed.
Furthermore, there is an idle control valve underneath the TB's that may be contaminated. A simple clean-up with carburetter fluid may solve the problem.
Add to that, the possibility of hair-line cracks in the hoses attached to it, especially around the hose-clamps. Last but not least, there is a 7th injector on the TB's of the M88/3 that is connected with a hose to the fuel-distribution rail. This part has an O-ring that may have dried out. This injector is connected to a bypass system that functions when all the TB's are fully closed, i.e idle mode. There are five O-rings in this system that may have dried out.
I think the temperature sensors sits behind the front bumper, I am sure there are many experts on the forum who can confirm/deny this. The OBC readout is generally accurate and consistent when travelling so I assume it must be subject to some heatsoak when stationary for a period on a hot day.
I have a substantial (£30k) history file for #16 and can also find no mention of any gearbox work, must have been a good batch when ours were built!
When the car is started from cold and when warming up it idles very smoothly at around 700-750 rpm. When hot, the idle seems to hang around 1500rpm. I usually dab the throttle a couple of times and is seems to come back to to 750rpm.
It seems number of other people on the forum have this problem, I am determined to get mine sorted out.
I replaced the AFM in the hopes this would solve the problem but no joy. The AFM was correctly set up for 1.5% CO.
From a previous thread, Batmoblile suggested that it may be the water temp sensor that is causing the problem. I will investigate this possibility Batmobile.
Raymond also posted this useful post.
"I am not going to rule out the temp sensors, but these generally are not the cause of an arratic idle. I hope that with the replacement AFM, you also adjusted the CO to 1,5% with the adjustement screw on the AFM? Bear in mind that the M88/3 has a center adjustment screw in teh middle of the TB's for cyl #3 and cyl #4 that controls the idle speed.
Furthermore, there is an idle control valve underneath the TB's that may be contaminated. A simple clean-up with carburetter fluid may solve the problem.
Add to that, the possibility of hair-line cracks in the hoses attached to it, especially around the hose-clamps. Last but not least, there is a 7th injector on the TB's of the M88/3 that is connected with a hose to the fuel-distribution rail. This part has an O-ring that may have dried out. This injector is connected to a bypass system that functions when all the TB's are fully closed, i.e idle mode. There are five O-rings in this system that may have dried out."
Last edited by Bayerische; 25th June 2009 at 14:10.
Linear Mode
