I have an 85 SR5 4wd 22re with a recent long block and new head. The ttruck idles great but when you get around 2600 rpm it starts to miss and cut out. There are no engine codes all vacuum lines seem to be ok. The tps checks out ok, the fuel filter was replaced. New wires,cap rotor,plugs. It acts like it might be fuel related but I can't seem to narrow it down. This one is driving me crazy any help or ideas would be great. Thanks

 

i know you got new plug wires but i got cheap ones when i did my motor and it started missing so i get a better set and it stoped just a thought might want to get a better set of wires

 

I know this is a little old and this problem is still driving me crazy but I stumbled upon a little more info. When the truck is first started and the engine is cold and at a high idle the miss that was happening at the 2500 rpm and above is gone. It revs up just fine. When the engine warms up a little and it is no longer at high idle but back down to normal idle the miss comes back. I have been able to reproduce this several times. Can someone tell me what sensor/device may come into the picture when the vehicle is warm and does not play a big part when it is cold? I am losing what little hair I have left. Thanks

 

Could it be a timing issue? Not sure which sensor your looking for...but my dodge does almost the same thing except it misses when its cold...then goes away when it warms up to normal temp. good luck

 

02 sensor maybe?

 

New O2 sensor. Not sure how the water thermo sensors play into the picture. Sensor on the thermostat housing, 2 below the throttle body, 1 on air valve that seems to route warm air up to the throttle body. No engine codes are present.

 

your cold start injector might be bad

 

I would check the fuel pump, if it's cutting out under load. It sounds like fuel starvation.

 

Any update in this? I have an 86 22re just rebuilt and its doing the same thing. Misfires above 2500 rpm but only after warm up. No miss when cold.

 

The IAT valve lets in more air to the intake when the engine is cold then less when warm. It's under the intake manifold. But I don't think it's the issue. I would try to adjust the valves. Mine would not idle correctly the way the valves were adjusted. But other problems might stem from this. Adjust valves with engine warm.If electrical and fuel are good the valves may be the culprit.

 

Newbie here I am having the same problems any idea what it is 22 re 85 model 2wd. new head job plugs wires cap button . I have also moved the timing a tooth both ways no difference. This is my first time doing a re I have done several 20r with no problem.

 

Egr valve is the problem. Not opening correctly. At cold engine temp found no problem because egr valve does not come into the picture until engine temp warms up to 111 degrees F and then the BVSV valve then opens supplying vacuum to egr acording to FSM. After engine warms up egr valve functions in conjuction with vacuum modulator. Replaced egr valve all good again. Tried to copy the page from the FSM that illistrates the egr,BVSV and vacuum modulator but uncertain how to do that. Good luck

 

Good to know, thanks. EGR was the issue on mine as well but new EGR valve and EGR modulator did not fix the problem on mine. We had to reduce orafice size of EGR. Almost all misfire went away after that but still have an occasional one. EGR still functions and passes smog with reduced orafice. If you want the whole story:
https://www.yotatech.com/forums/f116...advice-213660/