Hi all, I have taken on a new project, rebuilt a rolled 1989 extended cab 3vze 5spd bare bones 4x4. I swapped on a SR5 extended cab off a 1990 2wd with every option except a/c. To keep all the power options and cruise control, I used the entire wiring harness from the 2wd donar, everything was same except the TPS was a different plug, and the lack of 4wd light on the TC. I found a throttle body at the wreckers with the cruise control cable atachment that i needed and the correct TPS and swapped it on my engine. Everything works, the engine runs is running, but it has a very high idle. I have done some serious searching and reading of other threads, I followed other threads to clean the IAC and test the TPS. I have also read alot of the 93 FSM, and have taken the TPS off, checked the condition of the ICA (working fine) and checked the TPS as per the FSM. When I check the E2-IDL the reading is infinate. All other checks are within spec. With the TPS unplugged and the truck running, the exact same high idle occurs 1700-2200rpm. I plan to purchase a new TPS, but am wondering if there is something else that anyone can think of. I have double checked all the vacuum lines and all seem to be correct. The coolant system is empty at this time as I am waiting on a new rad to arrive. Would this possibly have an effect?

What else should I be looking at?

Thanks for your help.

Ian

 

I'm an amateur but here are a couple thoughts. Have you adjusted throttle stop screw? Clockwise is to close it. Have you had this at running temperature yet? High idle (1500 or) at first is normal to help bring engine up to operating temperature. Have you had coolant in this to drive around? If not, then that is an issue to some extent.

 

I have not adjusted the throttle stop, the throttle body is closed fully so I didn't want to start turning things just yet. I have not brought it up to temp yet, still don't have a windshield in it, or rad and a few other parts to complete before it is road ready. I know 1500 is expected on cold start, however 2200 is quite a bit above that. I may try to run it longer and see if it comes down, however no coolant in the system yet, so can't run too long.

 

Personally, I would not worry about the idle until it is all together and road ready. Not worth idling it w/out coolant in it.

 

And yes I would go ahead and buy the new Denso TPS from Toyota now. It's not too expensive. That's what i did. That will give you peace of mind regarding this critical part.

 

I may order it as you said for piece of mind. Only reason I am working on this now is because I am waiting for other parts before I can proceed, and thought I could work some bugs out while I have the time.

 

So today was the test drive, idle will not fall below 2200 once warm. I realized the idle set screw was loose and backed way out. This is a throttle body i got from the wrecker to be able to use the cruise control on my cab swap. I tightened it in until it seemed to become snug and stopped. The idle was about 900. I turned it in 2 more turns and continued to drive. I released that the truck was not fully warmed up because now the idle is too low and will almost stall. I turned it back out, however it just becomes loose. What is behind the screw? Can i clean this because i believe it is stuck in as i tightened and will not come back. Any advice, I couldn't find it in the FSM either.

Thanks,
Ian

 

Problem solved. Removed the screw and the o-ring was so dried and shrunk it didn't even make. Intact with the sides. Put on a new dash 11 7.8x11.6x1.9 and problem solved. It is still quite easy to turn so once I start driving this truck and get it set 100% I will add a drop of silicone to to hold it in place.