realtime help: high/surging idle at temp, with outside temp above 70-75F

[smokethedog]

I've been fighting this issue for sometime now, and need toget it fixed before making a cross country trip. My issue is when the ambient outside temp gets warm, above 70F or so, my idle speed jumps up dramatically (1500-2000 RPMs). In the winter, I do not see this behavior.

I did a search and found this thread (https://forum.ih8mud.com/showthread.php?t=61744&highlight=maf) , but did not see any resolution. I have just checked the MAF resistance settings according to the FSM, and not seeing ANY resistance b/w the THA and and E2 terminals. Before I drop any cash into a new MAF, just wanted to get some"expert advice" from you folks. I am assuming this is what is causing my issues, but it doesnt make any sense that it only happens in summertime temps?!?!? Headed out now to check the TSP.

I found some posts on the 100 forum that said the oil on a K&N filter can hose up the MAF. I did run a K&N filter for a couple of years, now back to stock. Could this have caused my issue?

Can anyone shed any light on this (why I only see this in the summertime temps, no issues in the winter)? How much is a new MAF meter?
thanks

 

[cruiserdan]

Possibly related to the A/C idle up?

 

[smokethedog]

Possibly related to the A/C idle up?

Does with the A/C off.

 

[CJF]

I have just checked the MAF resistance settings according to the FSM, and not seeing ANY resistance b/w the THA and and E2 terminals.

Since you're not getting much response, I'll state the obvious: Is this out of spec? Well, then replace it!...

Cheers,

Curtis

 

[Sandman]

I had a similar problem with my '95. Sometimes during hot weather the idle would go high enough to impede braking. I had gone so far as to popping the hood during a red light and manually forcing the throttle back. I replaced the fan clutch and adjusted the throttle cable. After coming off a trail, running slow and working the FZ hard, the idle was way up, when someone suggested that the truck was idling high to cool itself, so I took it down the highway a couple miles to get some air across the radiator, I pulled over and the truck was idling fine. That was when I checked the fan clutch and realized it was shot. After a while the high idle returned but not as bad as before about 1200 RPM. I checked the throttle cable for corrosion and checked the adjustment and found it to be a little tight. A simple readjustment using info from here on mud and all has been well. I am not sure why an out of adjustment throttle would act up only during the hot weather but this seemed the only time I noticed it.

 

[CJF]

I checked the throttle cable for corrosion and checked the adjustment and found it to be a little tight. A simple readjustment using info from here on mud and all has been well.

Good point; definitely check whether you can manually close the throttle.

 

[smokethedog]

Since you're not getting much response, I'll state the obvious: Is this out of spec? Well, then replace it!...

Cheers,

Curtis

Thanks, MAF meter = $600+, Thats a last resort option...

 

[smokethedog]

I had a similar problem with my '95. Sometimes during hot weather the idle would go high enough to impede braking. I had gone so far as to popping the hood during a red light and manually forcing the throttle back. I replaced the fan clutch and adjusted the throttle cable. After coming off a trail, running slow and working the FZ hard, the idle was way up, when someone suggested that the truck was idling high to cool itself, so I took it down the highway a couple miles to get some air across the radiator, I pulled over and the truck was idling fine. That was when I checked the fan clutch and realized it was shot. After a while the high idle returned but not as bad as before about 1200 RPM. I checked the throttle cable for corrosion and checked the adjustment and found it to be a little tight. A simple readjustment using info from here on mud and all has been well. I am not sure why an out of adjustment throttle would act up only during the hot weather but this seemed the only time I noticed it.

I replaced the fan clutch when I first got the truck about 3 years ago. It seems the hotter the weather, the higher the idle. When it is idling just a little high, 1200-1500 rpms, I could pull up on the gas pedal and it would drop. It was pretty warm the other day, and this didnt help. I will check the throttle cable this afternoon.
thanks for the info, really appreciate it.

 

[cpg]

I have had this problem 2 times in the last 2 years. Both times pulling the EFI main breaker cured the erratic idle. The last time i had to do it 2 times but the idle went back to normal. Easy too try.

 

[CJF]

I replaced the fan clutch when I first got the truck about 3 years ago. It seems the hotter the weather, the higher the idle. When it is idling just a little high, 1200-1500 rpms, I could pull up on the gas pedal and it would drop. It was pretty warm the other day, and this didnt help. I will check the throttle cable this afternoon.
thanks for the info, really appreciate it.

I'll bet it's the cable. Being able to semi-rectify the problem by pulling up on the skinny pedal confirms this. You need to get under the hood and see what's what.

Good luck,

Curtis