i have a 93 ext cap 4x4 with the v 6 . In the morning when i start it it dosen t idile that good. but i getit ging then. when i start down the road it runs good for about 4 miles. then it loses all it s power. the motor still reves up normal with clucth pushed in.you let the clutch out then try to go it just don t have any power. so while still moving i turn the key off and turn it back on it runs normal again. then in about 2 miles it s back to having no power. everytime i turn off the truck it runs normal. and it aso runs very hot. it stays right around the red line then drops alittle bit then right back up. the truck has 205,000 miles on it. i just bougt the truck about 2 weeks ago. the lady i boughtthe truck from says it was just rebuilt 600 miles ago. the first thing i did was replace the thermostat. that did nt work.
things i changed.
fuel pump,fuel filter, efi relay switch,air filter. i checked the egr valve ad the intake an it all looked good. the truck doesn t smoke either. i took it to the dealer and theyhave no i dea because the check engine ligh isn t on. anyone have any idea s. lets hear them. im thinking it s a efi prob. but why when i turn the key off it runs normal.

 

Greetings!
Since you said it doesn't idle that good and you just changed your t-stat, it leads me to believe that you have an airpocket in there and it needs to be burped. There's a couple of ways to get it out, fill up you engine with coolant by removing the upper radiator hose and fill it up here, replace the hose and turn your heater on, warm her up and she should burp out the radiator with the cap removed. I never cared for aftermarket t-stats, I never really seen them work that well and I never had any luck w/them, I like the Toyota brand only. Even though your check engine light isn't on you still might have a code, jump your "te" & "E1" connectors next to your fuse box under the hood with a paperclip and turn the key and check your codes on your dash, it will start flashing real fast if you have no codes, if you have a code it will flash like this: ** short pause *, meaning a code 21 for example, if you have more than one code there will be a long pause and it will then go onto the next code and start all over again. To clear the code, just remove the efi fuse for about 30 seconds or remove the neg battery terminal.
One more thing, check your TPS, respec it to make sure that is still in spec.


Good Luck!
* Harry *

 

for the info i ll try that tonight. but when the truck sits for more than 2 hours it dosent idil that good. it idil s fine afer about 5 min. any more opinions.

 

So, more or less it idles bad when cold? Did this problem start after you threw all these parts at it (fuel pump, filter...) ? Or did you throw all these parts at it hoping to cure your idle/power loss problem?
See now that your telling me exactly what it's doing it brings up more possibilities!
Is it hard to start after it sits? How's your fuel pressure and fuel pressure regulator? Did you check your fuel pressure? (38-44 psi)
If it's hard to start, meaning you have to crank it over for awhile before it starts, go into the check connector and cross "Fp" & "B+" terminals if it starts right up it's your Fuel pump and I know you already replaced yours but I got bad ones already!
Good Luck!!

* Harry *

 

i did the code thing and it says code 21. i did some checking and i guess that means o2 sensor. it starts right up. but then it idils wierd. last night i burped the radiator and there was air in it. i filled it back up today and i ll let you know how i make out. thanks for your help. i still hav nt fixed the power prob yet.i m going to put on the o2 sensor and see what that does

 

Be careful on that code 21 - It could be in the circuit itself and not neccessarly an O2 sensor - If you decide to go with a new O2 sensor, take your old one with you and match the nipples up, some of the aftermarket ones have shorter nipples and when you use these the nipples aren't long enough to read the flow of exhaust resulting in an O2 code!
Did you rescpec your TPS and/or take it off and try to clean it? They get gummed up something fierce!

Good Luck!
* Harry *