Hi guys, I changed my headgasket out about 1000 miles ago so I went out today to change the oil, retorque the head bolts, and adjust the valves. Before doing this, I had been having problems with the idle 'surging' at idle. I checked through my coolant and that was not the case, and I did some searching to find that it may be because my idle was set too high, which may have been causing my problem. Anyways, now that I adjusted my valves (which were a ways out of adjustment) the truck is surging again, but when the rpms drop (after the surge), the truck acts like it is going to die. It stumbles and acts as if the rpm were more like 400, but the truck is actually at 1000 rpm. It shakes real bad and almost dies as it slowly starts its surge again. Does this sound like I messed something up on the valve adjustment? or did adjusting the valves correctly cause something else to go out of whack, like perhaps the timing? I drove the truck around the block and under load it actually felt like it drove better than I ever remember it. Queit and seemingly better power. Any ideas? Before the problem got worse I was just going to mess with the idle stop screw a little to see if it would fix the surge, but now I think there is something more seriously wrong. Thanks for any help,

Dan

I had similar symptoms when the tube between my air filter and intake manifold developed a small split in one of the accordian ribs.

ok, I'm an idiot. Since you said you had similar problems when your intake cracked, I went out to check my vacuum lines and I had forgotten to connect one of the lines from the power steering pump. It's crazy because I stared at the engine for quite awhile trying to figure out what was wrong, and somehow I just overlooked it. I still have the surging idle problem I had before i did the valves, but at least I am back to that point now. Tomorrow I will do some further troubleshooting and let you know if I figure out anything on the surging idle. Unfortunately it doesn't just happen when I press the brakes, so it may not be the same thing that other people have been describing.

check to see if you low on coolant or burp it if you have air in the system it will cause this

Sounds to me like a vacuum problem.
check the line the runs from your booster to your intake. A way that worked for me to find vacuum leaks is to take a propane torch and turn it on BUT NOT LIGHT IT and run it around all your vacuum lines with the truck idleing. If the engine revs in a certain area you found your leak.
good luck

erick

EDIT

I second this.

It sounds like I have a similar problem with my idle. After reading the replies here I'll check all those things. I just made the following post on YotaTech. Any other things I should check? BTW, it's a '94 22R-E.

YotaTech post:
"It will idle just fine when I start it up, but after it gets driven a bit and I come to a stop it will jump back and forth from about 1500 to 1800 RPM. It surges every second; up and back down.

I'm thinking mine has to be a vacuum hose problem somewhere. When I step on the brake the idle drops to about 1000 and surges up to 1200 and back down again. There is some sort of vacuum line on the brake booster, right?

Anybody have any suggestions?
Thanks."

no no no no
there's a fuel cut off at 1,300K sposedly
goes down to 1k
if u use the brake at this rpm range, it goes off
so idle goes up and down
only cure is to set idle BELOW 1K like it's sposed to be...
there is a brake servo vaccum of course
has to be...
disconnect hose to see if it works
doubt it's yor prob