need a new computer. i think. dont know what else to do. and i took it to a shop.....

[crazywhiteboy]

ok, here goes the story again. i was out wheeling in the snow. broke driver front axleshaft. i have a welded diff so i had 3 wheel drive. the hill i was trying to get up was approx. 1/8 mile long. i hit it in 4low 4 gear, only cuz i needed the low gears to get some speed up cuz the hill was mostly ice. im spinning the 3 tires at about 4700rpms. i get to the top, and shut off my ignition. the engine tries to stay alive, then all the sudden the rpms jump to way over the limit on the tach. it was soo high it started sounding like a little diesel. then after 2 seconds, smoke starting coming out from under my hood. i opened the hood, and ripped the positive cable off the terminale. then it shut down....this all happened in about 10 seconds from after i shutoff the ignition. now everytime i start it, it idles at about 3000. sooo after talking to a few people on trs, they came to the conclusion that it sounds like a vacuum leak. i pulled all the vacuum hoses, and the plastic intake off along with the throttle body. it was all pretty gummed up inside there so i cleaned it all with brake cleaner. i got some rtv red high temp silicon and made sure everything had a good seal. waited a while, then started it up. dropped the rpms by about 500. now its at 2500. so today i took it to my mechanic, there wasnt a code, but the engine check light didnt come on when you turn the ignition on like its supposed to. sooo he said i might have a bad computer, and that i might have gotten it wet. anyother info that anyone else has would be greatly appreciated. i really dont know what to do, its my dd rightnow, and im short on work. so whatever i can do to it myself im going to....

 

[MAKG]

Can someone explain to me how a vacuum leak can make the engine keep running when the ignition is turned off on a fuel injected engine?

And if your mechanic jumps directly to the computer, you need a new mechanic. Sure it's possible, but you have multiple symptoms of a short to ground powering the emissions system.

 

[eli]

It could be a compound problem, does it still diesel on when your turn the ignition or was it a one time thing. if it happens all the time there could be a short to power on the IGN RUN circuit short to power or VPWR circuit short to power, which you find a Manuel and trace the wire and do electrical checks. As for the hight ideal it could be a problem with the MAf being dirty or in the circuit or the IAT could be a problem so try and get a scan tool and view the pids to find the range values

 

[crazywhiteboy]

i never said it was a leak. thats what i got from listening a few people on here. i guess they were wrong, and i was wrong for listening. i cleaned the maf. soo, it could be the computer but prob not? and no it doesnt sound like that anymore. that was a one time deal hopefully. but it still idles at 2500. why would it do that?

 

[eli]

For the high idle try using some propane around the lower intake to see if you have a lower vacuum leak, If you do the engine will race even higher in the rpms

 

[MAKG]

Another possibility for high idle like that is just that the computer thinks the engine is cold. And there are others. This will quite likely turn out to be something cheap like a bad ground, but the key is finding it. It's not AT ALL a good newbie DIY.

 

[Cybergasm]

Have tried Scanning for codes? that might give u a direction to head in....

 

[crazywhiteboy]

took it to another mechanic/family friend today. didnt have time to really pick it apart, but he did take a can of brake cleaner and sprayed down every vacuum line and joint visible. didnt do anything whatsoever. so he asked me what i have done so far, i told him checked the IAC, pulled the intake, sealed everything, and that it was still doing the same thing. then he said its not a vacuum leak, and that something is stuck open and its not just one thing. when i got home i pulled the IAC, had my dad put his hand over the holes were the iac was, and i started it and it idled at 850rpms. wtf? i looked at the little valve inside of it, and it was barely open. so i guess i need a new iac, but why doesnt my check engine like come on when things go wrong?