Pulling up on gas pedal to slow idle...

[jhstatts]

I recently replaced my water pump, fan clutch, thermostat, belts, oil cooler hoses and radiator hoses. Before I changed all this, my truck was idling around 900-1000 RPM. I know this is a bit high, but I didn't worry about it too much.

Now the truck gets warm and wants to idle at 1200-1300. When coming to a stop, the needle drops down to 900 when I first engage the clutch, but then shoots back up to the 1200-1300 range. I can bring it back down to 900-1000 by pulling up on the gas pedal, so I know it has something to do with the linkage not returning to normal. I tried to adjust it today, but couldn't figure out what I needed to do.

Also, my truck is running a little warm after all the work I did. Using the heater brings the temp down to 1/2 on the dial... without it, the temp goes to about 3/4. Before the work, 1/2 was pretty much the norm. Does belt tension have an influence on the temp? The belts seem to be OK, each has about a 1/2 inch of flex... no squeaks.

Thanks.

 

[Tinker]

The linkage rods are pretty simple - just don't remove more than 1 at a time. I'd clean & lube all the rod ends & pedal pivots with light synthetic grease. If one (either?) of the springs is worn, It probably won't return to idle properly.

Can't imagine why your temp has gone up. Did you follow the FSM, paying close attetion to the orientation of the thermostat? Did you use a 180?

 

[jhstatts]

I installed the thermostat with the small "ball" facing towards the radiator. I am pretty sure that was how the last one was installed. Would this cause the thermo to work improperly? I did use the FSM, but that doesn't mean much. This was my biggest wrenching project to date.

The springs seem OK. I don't know enough about them to make a call. They seem to be pretty strong.

Thanks, Tinker.

 

[CTiger]

seems like I came across a thread a while back that said exactly what linkage parts need to be replaced when you can pull up on the gas pedal and it lowers idle. You might try searching for that specifically...

 

[Pluton]

High temp readings(which I suspect are false,but I'd need an IR thermometer to check for sure) are common after draining and replacing coolant. It's occured every time I've done it. I just drive it normally, and at a certain point you look down at the gauge, and it's running at normal temp. One time it took about 50 miles, another time I left on a long trip and it took several hundred miles.

 

[jhstatts]

Well, all this got me thinking... so at 1:30 am I went out to check on my thermostat's orientation. It turns out it was backwards. Duh. I didn't think to check when I installed it... and just put it in the same way the PO had installed the last one. Now I know, but feel like an idiot.

The good thing is I did the re-install in under 45 minutes with a flashlight. The other good news is that I know the thermostat is installed correctly. One less thing to worry about. It was too late to test it, but I am hoping to see a better temp reading tomorrow morning.

Pluton... thanks. I had read that somewhere here a while back. That makes me feel better.

Still working on the high idle. I think I need a stronger spring on the pedal.

Thanks for all the help so far.

 

[FJ40Jim]

Jason,
Have you tried adjusting the idle speed screw?

 

[ROCKCLMBR 7]

I second jim, the idle speed screw would be my first clue than linkage and springs. did you bleed all of the air out of the system when you changed the h2o pump? that could cause slight overheating when you have a small air pocket in the system.
Start with the easy and obvious before the hard and un-apparent.

 

[jhstatts]

I did burp the system...

As far as my idle adjustment screw, it is capped. I have been afraid to drill it out. Now I hear a moaning sound from the engine... feels and sounds like it is coming from smog pump territory.

 

[WSUCruiser]

I found that Silkolene spray grease is really effective on almost everything. I know it is for cables, but it really works well and i have some lying around. My pedal pulling woes dissapeared after an application to the linkages

-Dave-

 

[notatreehugger]

After I changed my thermostat a couple of days ago, my temp gauge spiked into the red 4 or 5 times within the 30mile trip to work. Pretty sure its some air giving me false readings because it would drop 3/4 of the gauge before I could get stopped. Still, it freaked me out. I don't want to re-do the engine yet.

On the way back to the house it operated normally. Mine is a 3F, I was hoping the thermostat might correct the high idle problems(temp too low, computer trying to heat it up?) cheapest stab in the dark, but it didn't help. Adjusted the throttle cable, didn't fix either. Next step, Idle Air Control Valve. Does this sound like a good process of elimination?

 

[FJ40Jim]

As far as my idle adjustment screw, it is capped. I have been afraid to drill it out.

The capped screw on the valve cover side of the carb is the idle MIX screw.

The idle SPEED screw is located right against the back of the carb, down low.

 

[Doc]

If your idle drops when you pull up on the pedal, it's a pretty good indicator that you need to clean/lube the linkage and perhaps need a new throttle return spring (I think that's the name).