Why wont my truck idle ? ? ?

[Shearmanator]

Alright last friday coming back from my first time taking my yota out. I'm coming down a dirt road doing about 45mph and out of nowhere I hit this ditch coming perpendicular to the road that was about 1.5 feet wide and about 1 foot deep lets just say I hit it hard enough to knock myself unconscious on the roof of my truck and knock trim peices off of my interior that I didnt even know about. Anyways now my truck will not idle and when it is running it runs like total crap. I've checked everything and still cant find what s wrong with it isnt pulling any codes or anything. By the way it an 87 4runner w/ a 22rec. ANY ideas will be appreciated

 

[yotatilla]

I'm not one to condone paying someone else to fix your vehicle, but if I were you, I would bring it down to a local garage and have them check it out. If it comes up with something fairly simple, do it yourself. If they come up with something complicated, do it yourself. Just bring it down there and let them tell you whats wrong, but don't let them fix it. I have done it a few times, and they only charged like $40. It is really nice because they will tell you what is wrong for sure, and not just start pulling and replacing parts like you or I would. Sounds like a rough situation, glad your OK. Sam

 

[captwalker87]

most basic thing that could be wrong: engine fuse. if its blown, it wont idle, but it will run long as there is throttle. check it, you never know, it might be that simple.

 

[genlrony]

Its possible the you jumped time. I would defintily be looking at the timing.

 

[kreynolds]

I had a similar problem with my 88 4runner crusin down the freeway back off the gas to slow down and when I went to accelerate nothing no power no revs nothing. I could only get about 2500 rpms. It was like running on 2 cyl. Advancing the timing full tilt brought back the rpm's but would never pass smog tests. Turned out it had jumper time, two teeth on the timing gear and what caused it was the chain tentioner pad broke off. It runs ok now but only after replacing the timing chain. I still ahve a rough idle that I can't fig out.

good luck

 

[greasefingers]

Do you own a timing light?

 

[kreynolds]

No but a friend has one that I use. I know its not the timing well I'm almost certian its not the timing. It just past smog test and if its not within spec it fail right then even if the emmissions are within range. I was wondering if the 02 sensors were blown out if that would caus a rough idle. I already replace the throttle positioner after reading the flashing codes.

Any ideas?

 

[greasefingers]

The oxygen sensors are not used as Inputs to the ECU; until the coolant temp reaches operating temperature. So if she idling rough from the start then you can eliminate the O2 sensor as the culprit.

 

[kreynolds]

The oxygen sensors are not used as Inputs to the ECU; until the coolant temp reaches operating temperature. So if she idling rough from the start then you can eliminate the O2 sensor as the culprit.

Well I did a bit of checking and with the diagnostic terminal points grounded my check engin light blinked code 51. My Throttal Positioner has been replaced but I cheked it with an ohm meter and it checked ok. I would have to think that if something was amiss with the ECU, I'd have other problems to go along with my rough low rough idle. The last thing that was in my book to check was the AC Idle Switch and Circuit. I know that when new and I kicked on the AC the engine RPM would increase, Iassumed to balaned with the extra load of the AC. It hasn't done this for a long time. Problem is there is nothing in my book that tells me where to look for this circuit or switch.

Got any Ideas?

 

[Shearmanator]

Thanks for the input guys but it was actually because one of my motor mounts was loose and when I hit the ditch the engine bounced so much that it put a small rip in the rubber elbow where it turns a 90 into the throttle body that you couldnt see because it was on the bottom of it. A new elbow given to me for free fixed the problem after the truck was down for a friggin month.