Been struggling with a very high cold idle on my 22RE since getting it back on the road a couple of months ago. I had an entire intake from my son's old '89 4Runner (RIP), that had the "straighter" plenum and simpler throttle body, so I did the swap, using several write-ups on the web.
When I start it cold, the idle is really high (2000-2100 rpm), makes it hard to drive. But it does eventually settle down when fully warm, although not consistent. Sometimes it will get down to the 750 where it's supposed to be, but more often it's up around 1000. Really annoying. Checked throttle plate for free motion, the cable AND the dashpot are new, so nothing is binding. Every part was tested before it was put back on the engine, and every vacuum line was replaced with new OEM hose, so I'm confident that I don't have a vacuum leak, failed EGR, or failed sensor. So, I suspect the IACV (Idle Air Control Valve) on the bottom of the throttle body, which I didn't take apart prior to installing.
As an experiment, I pulled off the plastic intake and put a piece of Gorilla tape over the inlet hole, upstream of the throttle plate, effectively blocking off the IACV. Put the intake back on, started the engine cold, it would barely run, had to hold the throttle open just to keep it running. When I remove the tape, the high idle is back. That tells me the IACV is opening too far.
Pulled the TB off, removed the IACV, it was dirty but not clogged. Tested it in hot water, the themostat does close the air passage off, but not fully. Diagnosis: the spring is weak from lots of miles, age, and heat/cool cycles.
These things are a huge pain to adjust, assuming I can make a special socket to turn the adjusting collar. I'm thinking I should just get a new one. Sam quoted me $215 from OEM, ouch. Today I find that NAPA sells them, aftermarket, for $120.
I'm usually an "OEM ONLY" person, but this is tempting. Should I give it a try? Anybody ever gone this route?
I'm gonna be
if this doesn't fix the problem.
When I start it cold, the idle is really high (2000-2100 rpm), makes it hard to drive. But it does eventually settle down when fully warm, although not consistent. Sometimes it will get down to the 750 where it's supposed to be, but more often it's up around 1000. Really annoying. Checked throttle plate for free motion, the cable AND the dashpot are new, so nothing is binding. Every part was tested before it was put back on the engine, and every vacuum line was replaced with new OEM hose, so I'm confident that I don't have a vacuum leak, failed EGR, or failed sensor. So, I suspect the IACV (Idle Air Control Valve) on the bottom of the throttle body, which I didn't take apart prior to installing.
As an experiment, I pulled off the plastic intake and put a piece of Gorilla tape over the inlet hole, upstream of the throttle plate, effectively blocking off the IACV. Put the intake back on, started the engine cold, it would barely run, had to hold the throttle open just to keep it running. When I remove the tape, the high idle is back. That tells me the IACV is opening too far.
Pulled the TB off, removed the IACV, it was dirty but not clogged. Tested it in hot water, the themostat does close the air passage off, but not fully. Diagnosis: the spring is weak from lots of miles, age, and heat/cool cycles.
These things are a huge pain to adjust, assuming I can make a special socket to turn the adjusting collar. I'm thinking I should just get a new one. Sam quoted me $215 from OEM, ouch. Today I find that NAPA sells them, aftermarket, for $120.
I'm usually an "OEM ONLY" person, but this is tempting. Should I give it a try? Anybody ever gone this route?
I'm gonna be
if this doesn't fix the problem.
