Surging/ high idle
05-07-2018, 12:14 PM
#1
Registered User
Thread Starter
Join Date: May 2018
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
Surging/ high idle
hello there, created this profile because I’ve been doing some research and I need some specific input.
I bought a 93 pickup with a 22re. Replaced the head gasket, new water pump new timing chain and setup. Everything went smoothly. After completion we had some bugs to work out. Mainly high surging idle after a lot of research took the IACV or the AAV off and cleared it and the water lines leading up to it finding that they were completely clogged (with products I did not use on my repai). Problem solved right ! Wrong. Idle was still a touch high when warm 1200-1400. No vacuum leaks to speak of after moving some lines around and cleaning the intake system well I was able to get the idle down to 1000 not ideal but ok for me. Let it run everything good drove it around no issues. Later started it up ran it again. After driving idle surged again and idle kicked back up. I believe if I start it up with out touching the brake it runs ok. The second I touch the brake it starts the fuel stop system and surges the idle.
I am looking for any input to get idle down or if something In the brake booster is causing my issue.
also side note I am not sure how the idle up valve is suppose to work if you remove the large plastic screw and open it up all the way should that completely choke out the motor? I replaced the one on the truck with one from the junkyard because I did not believe it to be working correctly.
any help is much appreciated
I bought a 93 pickup with a 22re. Replaced the head gasket, new water pump new timing chain and setup. Everything went smoothly. After completion we had some bugs to work out. Mainly high surging idle after a lot of research took the IACV or the AAV off and cleared it and the water lines leading up to it finding that they were completely clogged (with products I did not use on my repai). Problem solved right ! Wrong. Idle was still a touch high when warm 1200-1400. No vacuum leaks to speak of after moving some lines around and cleaning the intake system well I was able to get the idle down to 1000 not ideal but ok for me. Let it run everything good drove it around no issues. Later started it up ran it again. After driving idle surged again and idle kicked back up. I believe if I start it up with out touching the brake it runs ok. The second I touch the brake it starts the fuel stop system and surges the idle.
I am looking for any input to get idle down or if something In the brake booster is causing my issue.
also side note I am not sure how the idle up valve is suppose to work if you remove the large plastic screw and open it up all the way should that completely choke out the motor? I replaced the one on the truck with one from the junkyard because I did not believe it to be working correctly.
any help is much appreciated
Last edited by Jdcoffey941; 05-07-2018 at 12:45 PM. Reason: Spelling issues
05-08-2018, 04:31 PM
#4
Registered User
Join Date: Jan 2017
Location: Atlanta
Posts: 50
Likes: 0
Received 0 Likes
on
0 Posts
I also experienced this problem after I did a headgasket and related new front end parts. I also didn't clean out my IACV and had to go back and do that. Did you clean out the EGR passages really well?
If you remove your brake booster from the situation (pull it and plug the vac line), does the idle change when brake is applied? There is some situation where the ECU will reduce the RPM, I think by cutting gas, when you hit the brake. you might be experiencing this. I think that if RPM is above ~1k at idle and you hit brakes the ECU may cut fuel. Unfortunately I cannot tell you _exactly_ what I did to stop this. I basically kept beating on the thing until all issues were solved. I thought (wrongly) that putting in the new headgasket would suddenly deliver me to the promised land of wonderful 22RE experience. Wrong. It was just the beginning of the process of getting the whole engine working correctly. BTW, I did end of having a bad brake booster and changed it and that may have been part of the problem (I sized it up and have more braking power now!), but that didn't solve the idle surge with brakes. Still, the booster is certainly a good place to start looking. If not that then check carefully for other vacuum leaks if the RPM drops consistently when you hit the brakes with booster tube plugged. And it sounds strange, but make sure coolant level is high/burped and reservoir is to the correct level. If there is a consistent link between brake applied and RPM change you can also pull the fuse to the brake light and see what happens. This will tell you if the vacuum is doing the weird stuff because the ECU responds to that brake light connection to cut the RPM. Have you checked the timing and is is set to factory spec?
Most recently just FYI as we're having similar gremlins, I had to block off my EGR to get the engine to stop missing after the headgasket. When you rev it up to ~2500+ under no load does the engine miss or shake randomly? Others who recently rebuilt and cleaned out the EGR really good had a similar issue: https://www.yotatech.com/forums/f116...advice-213660/
If you remove your brake booster from the situation (pull it and plug the vac line), does the idle change when brake is applied? There is some situation where the ECU will reduce the RPM, I think by cutting gas, when you hit the brake. you might be experiencing this. I think that if RPM is above ~1k at idle and you hit brakes the ECU may cut fuel. Unfortunately I cannot tell you _exactly_ what I did to stop this. I basically kept beating on the thing until all issues were solved. I thought (wrongly) that putting in the new headgasket would suddenly deliver me to the promised land of wonderful 22RE experience. Wrong. It was just the beginning of the process of getting the whole engine working correctly. BTW, I did end of having a bad brake booster and changed it and that may have been part of the problem (I sized it up and have more braking power now!), but that didn't solve the idle surge with brakes. Still, the booster is certainly a good place to start looking. If not that then check carefully for other vacuum leaks if the RPM drops consistently when you hit the brakes with booster tube plugged. And it sounds strange, but make sure coolant level is high/burped and reservoir is to the correct level. If there is a consistent link between brake applied and RPM change you can also pull the fuse to the brake light and see what happens. This will tell you if the vacuum is doing the weird stuff because the ECU responds to that brake light connection to cut the RPM. Have you checked the timing and is is set to factory spec?
Most recently just FYI as we're having similar gremlins, I had to block off my EGR to get the engine to stop missing after the headgasket. When you rev it up to ~2500+ under no load does the engine miss or shake randomly? Others who recently rebuilt and cleaned out the EGR really good had a similar issue: https://www.yotatech.com/forums/f116...advice-213660/
05-08-2018, 05:12 PM
#5
Registered User
Thread Starter
Join Date: May 2018
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
My egr is gone/ bypassed it’s hard to explain because it was done by previous owner but what I’m looking at seems ok. And all vacuum is sealed so should not be an issue I will give some of the around and with the brake booster and give it a look. It strange because other times seems to be worse. The idle will be higher which will obviously cause the brake fuel cut to activate and other times it does not seem to be as big of a deal.
05-11-2018, 04:53 PM
#6
Registered User
Thread Starter
Join Date: May 2018
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
Fixed!!
It is embarrassing but it was not my first attempt at this fix. But if it helps someone in the future it’s worth the post. I had tried a number of times to rotate the distributor but it felt maxed out. Frustrated with dead ends I decided to pull distributor and retard the timing. When I took everything off the distributor was able to rotate about 40 more degrees counter clockwise 20 degrees of that set my hot idle at 700!!’ Problem solved truck is complete !
Thread
Thread Starter
Forum
Replies
Last Post
