G
Guest
·Once my car has been runing for a while and gets to average temp the rpm's jump from reg idle down to like 300rpm :evil:
RPM jump
1 - 17 of 17 Posts
G
Guest
·Someone plz help me solve this problem
G
Guest
·Someone plz help me solve this problem
G
Guest
·not sure if this will help with your application and im not sure how to do it, but there is a thing in the engine bay to turn up the idle of your car. meaning just make it idle higher. but if its at a normal rpm and just drops down every so often, then i am not sure. sorry man 
G
Guest
·It goes up to like 1500rpm and drops to like a bit over 500rpm but this only happens every once in while
G
Guest
·Hi I have the same problem;
base idle is set correctly but when the engine is warm when I take my foot of the gas and dip the cluth the car tends to stall - sometimes the revs hover at about 300 then pickup but often it dies :-(
Help please !
base idle is set correctly but when the engine is warm when I take my foot of the gas and dip the cluth the car tends to stall - sometimes the revs hover at about 300 then pickup but often it dies :-(
Help please !
G
Guest
·check you idle air control valve (iacv) which is located on the back of the intake manifold....
G
Guest
·Yeah, set the idle properly, and have changed the valve - but no improvement
G
Guest
·I had this exact problem, same problem on my ZC.
After it warmed up, it would intermittenly pulse from 750 to 1200 rpms. Almost like I had a set of cams. I tried everything diagnostic and even stumped a couple qualified Honda techs. Replaced and/or substituted a lot of parts, even the ecu. Followed the Helms troubleshooting until there were no other options.
Anyone remember David Moore? He even spent an entire day doing diagnostics with his obd-0 datalogging tool. With it being intermittent, we spent the entire first half of the day not experiencing the problem...but it finally started doing it in the afternoon.
Based on the datalogging, the ecu was getting some freaky o2 sensor input and responding in kind. Like the ecu expects to see a voltage range of, say in generic units, 50-60 but it was seeing like 10-200.
I had already replaced the o2 sensor, checked the wire for breaks, grounds whatever. Replaced the o2 sensor again...still pulsing.
The header I was using put the o2 sensor right in front of the cat. Some people theorize this is a bad lacation for a non heated o2 sensor because the exhaust gas has cooled enough not to be read correctly by the time it reaches that location.
Tried swapping back to the stock header, the problem stopped and I thought I had it solved.
It was back a couple days later...
After all my own efforts....paying for dignostic time with a Honda tech and a private garage, Davids time, all the parts, sensor swaps and electrical troubleshooting...and the fact that the thing burned roughly a quart of oil every 2000 miles I had had it.
This was the final straw in deciding to put a new engine in. Not another used a ZC. One that was freshly rebuilt.
Not what you wanted to hear, I'm sure, but maybe my experience can help somehow.
After it warmed up, it would intermittenly pulse from 750 to 1200 rpms. Almost like I had a set of cams. I tried everything diagnostic and even stumped a couple qualified Honda techs. Replaced and/or substituted a lot of parts, even the ecu. Followed the Helms troubleshooting until there were no other options.
Anyone remember David Moore? He even spent an entire day doing diagnostics with his obd-0 datalogging tool. With it being intermittent, we spent the entire first half of the day not experiencing the problem...but it finally started doing it in the afternoon.
Based on the datalogging, the ecu was getting some freaky o2 sensor input and responding in kind. Like the ecu expects to see a voltage range of, say in generic units, 50-60 but it was seeing like 10-200.
I had already replaced the o2 sensor, checked the wire for breaks, grounds whatever. Replaced the o2 sensor again...still pulsing.
The header I was using put the o2 sensor right in front of the cat. Some people theorize this is a bad lacation for a non heated o2 sensor because the exhaust gas has cooled enough not to be read correctly by the time it reaches that location.
Tried swapping back to the stock header, the problem stopped and I thought I had it solved.
It was back a couple days later...
After all my own efforts....paying for dignostic time with a Honda tech and a private garage, Davids time, all the parts, sensor swaps and electrical troubleshooting...and the fact that the thing burned roughly a quart of oil every 2000 miles I had had it.
This was the final straw in deciding to put a new engine in. Not another used a ZC. One that was freshly rebuilt.
Not what you wanted to hear, I'm sure, but maybe my experience can help somehow.
G
Guest
·I've got a bit more info...
When I reset the memory on my ECU its good for 20-40 miles or about an hours driving.
Then the problem starts to occur - its as if the ECU has decided to run the engine differently and stored that in the memory.
Its almost as if the ECU doesnt fuel the car enough at that point.
My car doesnt have an O2 sensor.
To get the Hydrocarbons down to about 400-500, and a good Lambda reading, I have to have the CO set to about 2.8 - which is very high.
Help! :?
When I reset the memory on my ECU its good for 20-40 miles or about an hours driving.
Then the problem starts to occur - its as if the ECU has decided to run the engine differently and stored that in the memory.
Its almost as if the ECU doesnt fuel the car enough at that point.
My car doesnt have an O2 sensor.
To get the Hydrocarbons down to about 400-500, and a good Lambda reading, I have to have the CO set to about 2.8 - which is very high.
Help! :?
Joined
·
486 Posts
I had that problem.. the motor like revs up then down...From my experience with the zc it could be the tps sensors,vaccum leak,iacv. mine was the tps sensor
G
Guest
·PCV? Purge control valve? How can I test the valve?
Or is that the Positive Crankcase Ventiliation valve?
My car doesnt have a catalytic convertor or one of those charcoal canisters.
Thanks for your help...
Or is that the Positive Crankcase Ventiliation valve?
My car doesnt have a catalytic convertor or one of those charcoal canisters.
Thanks for your help...
Joined
·
486 Posts
pcv valve will cost you about 3 bucks from advance auto. it's located on one of the intake runners closest to the cam gears
Joined
·
486 Posts
Thats no problem man I'm glad I could help, I guess my 3 years of dealing with a zc or two let me learn a good bit about them. I ran mine to 7,800 rpms all day and everyday for 2.5 years with no problems
G
Guest
·Thanks for your help...I will give it a try!
1 - 17 of 17 Posts
