runs rough after rebuild head
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runs rough after rebuild head
I blew a headgasket due to electrolisis on my 89 4Runner w/22RE in it. I had the head rebuilt, put it all back together and it started right up. It ran smooth for about 3 or 4 seconds, then started running real rough, slowed way down and stalled. You can keep it running at a higher rpm and it's smooth, but it wont idle. I checked all the vacuum lines, can't find any vacuum leaks. Checked and rechecked the timing chain and proper rough timing.
I can't see any of the many sensors that aren't hooked up; they look fine. I had one run similar to this with a faulty MAF but cant find anything wrong there either. This Runner ran real good even after I blew the headgasket. I drive it into my shop to tear it down. It almost seems a timing problem, but it isn't. I'm stumped. Any ideas? Thanks
I can't see any of the many sensors that aren't hooked up; they look fine. I had one run similar to this with a faulty MAF but cant find anything wrong there either. This Runner ran real good even after I blew the headgasket. I drive it into my shop to tear it down. It almost seems a timing problem, but it isn't. I'm stumped. Any ideas? Thanks
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Re: TPS; I'll look at that again, but I didn't disturb anything on the manifold. I checked the idle adjustmment also. When I did the job I just removed the throttle body and ubnbolted the intake enough to lean it back out of the way. I unhooked a few sensors such as cold start and temp sensor plugs on the manifold. I took the egr off. Everything went back on pretty well. I'm no pro wrench, but this wasn't too big a job. Most of the sensor connections were unique to their sensor, and the vacuum connections are posted on the inside of the hood. I have rechecked all of these.
I just have to believe someone here has encountered this before. Thanks for the suggestions so far.
I just have to believe someone here has encountered this before. Thanks for the suggestions so far.
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Well, re: grounds, I'm pretty sure I got them. There was one from the firewall to the head, and another ground on the passenger side to the block. There is also a metal bracket to the intake. Re: timing, I need it to run to accurately time it. It is close, and I have the jumper wire on it. It starts right up and you can keep it running at a relatively high rpm. Maybe 1500 or more. It sounds good at that rpm.
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Thanks for the continuing replies. I am checking everything and still havent found the problem, Re: possible one tooth off; wow, I was meticulous about that. It runs real smooth at higher rpms. I don't think it would do that.
Re: adjust valves; did it twice; they'er right on .
What I'm doing next is ohming out each of the sensors. Dang WTH; I found the knock sensor doesn't have anything hooked to it. I can't even find the wire yet. Would that cause my problem? It looks kinda dirty, like it may have been unhooked for a while. What would be a symptom of a knock sensor that is not hooked up. BTW, I don't have any fault codes showing yet.
Re: adjust valves; did it twice; they'er right on .
What I'm doing next is ohming out each of the sensors. Dang WTH; I found the knock sensor doesn't have anything hooked to it. I can't even find the wire yet. Would that cause my problem? It looks kinda dirty, like it may have been unhooked for a while. What would be a symptom of a knock sensor that is not hooked up. BTW, I don't have any fault codes showing yet.
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Most throttle position sensors "fail" between closed throttle and 15% open throttle. If you think about it that is the position where they spend the most time. They develop a sort of dead spot but at a different position can seem fine.
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Well, you guys have my attention. I will ohm that sucker out as well. It just doesn't make sense for something like that to be the problem, since I haven't touched it, and it worked fine before I took the head off. I hope that's it; we'll see.
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Well, it was a vacuum leak. I thought it sounded like one, but I couldn't find it. Couldn't use brake cleaner or propane. because the engine only ran at a higher rpm anyway. I fond it by feel. Loose bolts back by the 'EGR. I thought I checked them. I feel stupid, but at least it idles now. Thanks for the help .
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