Fluctuating idle? Embarrased @ redlights?

Post by **Custommx3** » December 6th, 2005, 1:18 pm

Just a quick note...

Alot of people have problems with fluctuating idle too when 1st doing a ZE swap.

Ever get embarrased @ a red light? Hit the defroster switch. It applies a load and stops the fluctuating temporarly. I have fluctuating idle problems every once and awhile and I use this as a temp fix. I have yet to tune my ZE, just breaking it in. 430 miles as of today

babyblueMX3 · Post by **babyblueMX3** » December 6th, 2005, 1:57 pm

hehe nice barry
have you tried to set the tps ?
what voltage do you have closed and WOT ?

Post by **Custommx3** » December 6th, 2005, 2:38 pm

Havent done all that yet. Working on alot of PCs on the side (its christmas time

) so I dont have alot of time to work on it yet.

My RS is still down. Havent even touched it in 2 weeks.

hoffman_BMX89 · Post by **hoffman_BMX89** » December 6th, 2005, 5:59 pm

my idle is whak too it goes 1000 to 1500 rpms and keeps jumping like the it drives me insane what is the deal with that how do i fix it

hppwdn · Post by **hppwdn** » December 6th, 2005, 6:07 pm

A lot of idle problems like that are caused by a vacuum leak.

Another quick fix at the light that's really not good on your car at all is to put it in first gear, hold down the break and slowly let out the clutch until your RPMs drop down. No where near an intelligent thing to do, but if you really need to get the revs down it will work.

Teal_93 · Post by **Teal_93** » December 6th, 2005, 6:11 pm

mine did that when I removed my TB coolant lines when it got colder out. Rehooked them back up & it works just fine.

Rick Johnson · Post by **Rick Johnson** » December 6th, 2005, 6:17 pm

I have the bouncing idle on cold starts and it revs to 3,000 rpms when its -30 out which isn't a good thing. This weekend im going to check everything and try to figure this out.

jschrauwen · Post by **jschrauwen** » December 6th, 2005, 7:35 pm

I think all 3 items previously mentioned can be the root problem. In Barry's case when applying an electricl load I would agree with Steve and look towards a real serious (read thorough) TPS adjustment. When I finally acquired one without excessive blow-by through the butterfly, I was able to get a spot on idle that hasn't presented any idle surging whatsoever. WRT cold temps, either having the ISC disconnected or faulty, will generate it too. Of course having the TB coolant lines disconnected does nothing to help during cold temps either. Vaccum lines is another consideration. I will mention that I did experience severe idle fluctuations just prior to my water pump letting go where I was loosing considerable amounts of coolant just prior to. The coolant thermosensor wasn't making contact with the warm coolant and therefore promped the ECU to deduce that the engine was cool/cold and promptly readjusted the fuel mixture for a higher idle to compensate.

FlyVFR · Post by **FlyVFR** » December 7th, 2005, 1:08 pm

Ever get embarrased @ a red light? Hit the defroster switch. It applies a load and stops the fluctuating temporarly. I have fluctuating idle problems every once and awhile and I use this as a temp fix.

I was troubleshooting a vacuum leak which gave it the fluctuating idle. I used to shut it down and play with the radio at a red light. Needless to say the people who got stuck behind me were not thrilled about the extra wait. Oh well

Post by **Custommx3** » December 7th, 2005, 1:16 pm

this trick doesnt always work, but it hasnt failed me yet, then again, it doesnt happen too often.

Mnemonic · Post by **Mnemonic** » December 7th, 2005, 1:47 pm

i dont have this problem but i do have the problem of only getting about 150 miles to the tank

MX3 GSR for dummies · December 7th, 2005, 4:39 pm

I had rich mixture, throttle bouncing and missing as a result of my Ze swap but as soon as I installed my KL31 ECU, mycar has been wonderful. I don't know how many of you with the ecu swap have idle issues but in my case I thought it was just linked to the improper ecu.

hgallegos915 · Post by **hgallegos915** » December 7th, 2005, 11:08 pm

mines doing that with the k8 ecu.. i think also with the kf...ill check it out tomorrow..its basically the idle control valve thingy iac under the throttle body. I got a spare..ill swap when its noit that cold (probably in 4 or 5 months)

MX3 GSR for dummies · December 8th, 2005, 8:23 am

hgallegos915 wrote:mines doing that with the k8 ecu.. i think also with the kf...ill check it out tomorrow..its basically the idle control valve thingy iac under the throttle body. I got a spare..ill swap when its noit that cold (probably in 4 or 5 months)

I don't think it is the iac since I am running everything KLZE spec except for the TB with sensors. Although this just might be my luck.You would want to change the whole TB to a KL68 and have the isc and tps changed as well rather than just change the iac anyways. Since it is cold, I am going to wait it out and then change the TB and iac since my car is running stable now. Now that I think of it, I think the iac is the same for both motors anyways...if anyone knows for sure, please post.

Nd4SpdSe · Post by **Nd4SpdSe** » December 8th, 2005, 8:46 am

One question...does it only fluctuate when you have your foot on the brake pedal?

Myself, when i had that issue, it was a defective PCV valve.