dptoy94

I just change the timing chain and head gasket on my 22re. When I crank the truck it idles great until it warms up. Once it warms up it has a real bad surge that kills the engine if you don't keep it throttled up. I am going to see if I can started pulling codes later today. I checked all the normal stuff like loose wires, vac lines, etc. I was never able to set the timing do to the surging idle. Any suggestions will be greatly appreciated.

TNRabbit

I suspect a vacuum hose is unplugged, or you have a leak in your intake hose. It runs very rich until warmed up, so when it leans out you're getting your idle problem. Typical vacuum issue.

dptoy94

Thanks for the suggestion. That is the first thing I looked into. I even sprayed starting fluid around to see if I could find a vac leak but no luck. I will look again and also see about pulling any codes it may have. I have suspected either vac line or loose wire but can not find any as of yet.

abecedarian

What do you mean by it idles fine until it warms up? It goes up to 1100-1500 rpms when cold? ... or idles at 800 or so?
Did you check and set the valve clearances after the work?
Sure you've got the chain installed properly? If the cam timing is off it can cause a hunting idle due to low engine vacuum.

TNRabbit

There are vacuum lines leading all the way down to the front diff; are you sure you checked them all? There's MILES of them....

dptoy94

Timing chain was checked about 10 times before I started to reinstall everything. When the truck is cold it cranks as it normally did. After it comes off the high idle the motor starts surging and once it gets to this point it will surge every time you crank the truck. I think it is searching for the timing position like suggested. Besides the fact that it is surging it sounds fine. I have yet to check the timing due to the surging issue. As far as the front diff. it is a 2wd truck.

I was tied up the last couple of days on another project, hoping to get back to this one this afternoon. I really appreciate the suggestions. I know how hard it is to help troubleshoot anything when you are not there to see and hear what is happening. Thanks very much guys. Hopefully I can narrow it down tonight.

dptoy94

The damn EGR valve was the problem. I pulled the vac line on it and the motor calmed down. Thanks for the help guys.