I think 550 has got to low. I have to feather the throttle to keep it from stalling. I did not witness a change in idle from cold to hot.
Maybe, perhaps 580rpm is ideal. I didnāt think 550rpm would cause stalling.
You may need a TPS reset.
I believe these cars are supposed to relearn itself over time. Iāve never had the patience though.
I replaced my idle control valve almost to the day one year ago. Got in the car (96 XJS 4.0) this past weekend, started it up and it immediately idled to 3K RPM. I found these instructions in an older thread and proceeded to follow the steps below in an attempt to remedy the issue:
*. Run engine until you reach normal operating temperature.
*. Switch ignition off.
3. Switch ignition on, wait 5 seconds, then disconnect the
connector to the idle speed controller.
*. Switch ignition off.
*. Wait 15 seconds then reconnect idle speed controller.
*. Repeat two more times (steps 3 ļæ½ 5)
*. On last repeat, do not reconnect idle speed controller.
*. Start the engine.
Check the base idle speed, which should be at 550-600rpm.
If the idle speed is not within these limits adjust the air
bypass screw
to bring the idle speed within these limits.
Switch ignition off and reconnect the idle speed controller.
Start engine and check to ensure that the idle speed is
between 650-800rpm.
This procedure immediately brought the idle down to normal. Unfortunately, the high idle returned after turning the engine off and restarting a few minutes later. Just for the heck of it, I pulled out the old idle control valve that I replaced a year ago and pulled the piston out. I then replace the new ICV with the old unit knowing I would have a good seal with the piston and seat and left the connecting plug wire disconnected. Started the engine up and got good idle.
Question- are the ICV known to frequently fail? Is there anyway to test an ICV? Could the ICV be receiving a signal from another faulty devise thus causing the issue?
Thanks - Kevin
You will get Idle control valves for the price of Ā£12 Sterling - reaching as high as Ā£150. These are usually non-production spare parts. No reason to expect these to be good quality. Just buy another cheapest one, you will either get one working well or jamming.
It is worth mentioning that idle control valve shouldnāt give you 3k rpm even if in fully open position. Was it happening on cold/cold-ish morning? It rather looks like electrical problem. Start your engine in limp mode / with MAF unplugged and check if the revs wonāt be exactly as high as noticed onbyour ICV.
The cam position sensor went out on my Honda. Paid $150 for an OEM one. Can get cheaper, but this thing is so difficult to get at (cam cover and timing belt cover both have to come off) that you want the best you can get.
13 months later, craps out again. This time I paid $8 for the made-in-China version. Itās been in there for several years now.
Meanwhile, the same sensor on my Mazda would take all of 30 seconds to replace. Itās right on top of the engine, one bolt and one electrical connector swaps it out.
Can you apply 12V to those things and watch them whirrrrrr that plunger in and out?
Kirbert, guessing your honda is no longer in series manufacturing.
There is a big automotive secret in there to reveal. Every car manufacturer has two types of parts - manufacturing parts and spare parts. In terms of quality both could be seriously radical. Usually, for spare parts, the amount of acceptance criteria and manufacturing requirements drops by 60-80%
Conclusion.
As a manufacturer - you will get different level of reputation loss on the failure/recall of the new car just sold to unlucky customer, different on the failing part that can be returned and replaced by seller (after carās warranty period)
During car manufacturing cycle - all parts are usually production components. After manufacturing cycle closure - some are purchased from suppliers as spares, some are still production components from still manufactured modelsā¦
No, you usually have to pulse them, make and break repeatedly to move them.
I took the original Idle control valve and installed it with the piston fully extended to ensure a good seat. Instead of connecting the wire connection to it, I connected it to the replacement idle control valve I installed last year and witnessed no piston movement at idle or when turning the ignition off and on. I assume I have two bad units.
Question - Can I damage anything by not having a functioning idle control valve? The engine starts right up, idle is good but fluctuates very slightly and it seems to drive fine with no issuesā¦
Kevin
Doesnāt sound right if both units seems to be faulty (probabliltiy-wise). Have ypu checked witing look for damage/chaffing etc? Can be also checked with mutlimeter (min/max function is a must).
You can install your idle control valve on fixed position in AJ16, it should correct the rest with TPS, MAF, Lambda, but donāt expect it to be functioning well on idleā¦
Have you checked for any errors reported by ECU? Usually - disconnected ICV should be reported by ECU after 30ish cycles. Just guessing as this is an OBD standardā¦