2.9 High Idle

[laminad]

I have a 87 BII with a 2.9. First start of the day it low idles for a few seconds than normal, every start after that the rpm goes up and touches 3 grand and then right back down to 900. Runs great down the road, shut it off and re start and right back to 3 grand then 900 again. New map sensor. Maybe tps sticking, or could vacuum cuase this.

 

[customrangers1]

mine does the same, as well as bogging down to almost nothing after 2 or 3 minutes for about 30 seconds then it runs perfect-did you find anything out?

 

[Gary101386]

check your IAC. Idle air control. Mine did the same thing, then i took off my IAc and cleaned it with some WD-40 and a tooth brush and i havent had the problem since...

 

[armadillon]

Everyone keeps beating me to these answers. I would have initally said vacuum leak, but it levels out just fine, which screams IAC

 

[laminad]

IAC makes sense, I was thinking vacuum but did not start tracking it down. Right now I have it sitting, rear fuel pump has gone bad, everyone around here says special order only. So waiting on it now. In the mean time I went to tighten up the belts and the bolt striped out on the alternator, so had to drill and threw bolt it for now.

 

[laminad]

Rear fuel pump arrived and is installed, I found out what 25 years of fuel does to a fuel tank, about a inch of crap built up on the bottom. The float was disintegrated. Put about 50 miles on it today with out any problems.

 

[turbo2.9]

high idle "problem"

Hello, I have kind of the same problem ive got a 2.9 and wiring from a bII in my ranger. i just got it running a little while ago and when i start it when its cold it will idle up high for a sec and then will drop down to idle instantly. Now ive checked the IAC, cleaned it out and tried a couple different ones too with the same result. Also just the other day i was pulling on the wires of the IAC and it would open and close so i cut the plug off and put a different one on there and now it idles up normal on cold start but it still does the same when i start it when the motor is warm.

Ive replaced the FPR, fuel filter, and a couple more things and was just wondering if someone knows something else i could try.

Thanks! sorry for the confusing message and im not trying to thread jack but just figured it was related to laminads problem.

oh and other than the high idle on start it seems to run just fine

 

[laminad]

anybody at anytime can post on my thread, about anything, does not bother me at all. But as for the idle, that bothers me. ha ha. On my truck after I changed the fuel filter and the rear pump the 3 grand jump at start up went away. (go figure). But it still goes up to about 1 and a half and then back to 900. If I remember right when it was new it had a high idle when it was below 30 degrees outside. I am starting to think that it might be in the valve that the green and red vacuum lines are going to. Mine is original, there has to be a diaphram in there. Think I might just redo the vacuum system along with the egr. Or just get rid of the egr.

 

[laminad]

O.K. the starter and alternator are on. I also cleaned the IAC with throttle body cleaner. It runs much smoother, but I can unplug it and there is no change, also when it is pluged in my airbox with filter hums kinda loud, what is that about. Also after I cleaned the IAC I had to bump up the idle, it had dropped down to 700, which will turn on the oil light after a rev.