Hello, I apologize if this has been covered already, I couldnt find any forums with the same issue I'm having.

I have a 1985 toyota pickup with a 22re engine. I got it with a blown head gasket and put a street rv head and 261 crawler cam on it. I got it running but it's still having a few bugs. Right after I got it running I got a check engine light which I found was a bad O2 sensor so I replaced that which got rid of the check engine light but ever since I got it running, it has not idled correctly.

What it's doing is I will go to start it and it will fire right up then a second later the rpms will drop down and die. It will fire right back up and do the same thing again. It does it when it's cold and when it's hot but it's worse when it's cold. If I hold a little gas it will stay running and I can slowly let off the gas and it will idle after that but it surges. I have tried to adjust the idle down but with the idle screw in all the way, it will only go down to about 900rpm. It usually stays around 1000rpm when it's warmed up and idling. I have checked the timing, and coolant level which are ok. I'm leaning towards the idle air control valve but want to see what you guys think. It doesn't seem to idle up when it's cold which was one reason I was thinking the iacv. I did remove it and open it up and it looked clean with no obvious defects. I also replaced the fuel filter with a new one when I did the head, and I put rebuilt stock fuel injectors on it. I can also hear the fuel pump running when the key is in the on position.

It sounded like a vacuum leak to me when I was first thinking about it but I have taken a spray bottle and sprayed all the vacuum lines and my intake tuning with water and haven't found anything.

It also seems to be running rich. I can smell it in the exhaust and when I filled it up last I only got 14 mpg. In running stock gearing with 33's and a 4 inch lift. My commute is 20 miles one way and about 2/3rds is on the freeway.

Any help would be greatly appreciated. Thanks

 

How is the dashpot? Sometime it may need a little adjusting as it wont let the throttle close all the way at times.

The revving up and down can be that the cooling system needs to be burped. Raise the front end as high as possible and let it cycle the thermostat with the radiator cap off. An air pocket in the system will cause idle to surge.

 

X2, I agree

 

Thanks guys, I do have an update.

I disconnected the dash pot and it was holding the idle up a little. But it still wouldn't hold an idle.

I also bypassed the fuel pressure regulator vsv and ran a line directly to the fuel pressure regulator instead.

When I did the head gasket, I replaced the plugs and wires but not the cap or rotor. Today I decided to get a new cap and rotor just because it was something I didn't do and it was cheap. When I replaced it the truck now idles well with just a little surge. What I ended up finding was that the metal arm on the rotor was loose and was able to move in and out about an 1/8th of an inch. I'm assuming this was changing the timing and causing it to die.

I know that my iacv isn't working correctly so I have a new used one on the way so hopefully that will help too. It doesn't idle up when it's cold so it should fix that.

I'm also planning to burp the cooling system this weekend so that may help too