I have a 1986 Toyota SR5. It keeps throwing a code that either my TPS, or ECU is my problem. I took the ECU out, and checked the connections cleaned them, put dielectric grease on it, and put it back in. My check engine still won't go off. I've tried to reset the ECU every way and it still won't reset. I've put a new temp sensor and new end on it, plugs, plug wires , distributor cap, rotary button, new thermostat and gasket all on it. It still won't let me reset the ECU. When I first get in it of a morning and start it up, it runs horrible. Barely will run. After it warms up, it runs alot better, but it still seems like it's running a little hot, tho the gauge is working and according to it, it's not running hot at all. My fan is good, and my water pump is still good. I even took the end of the ground cable off, that's grounded to the fender and cleaned it good. Never helped at all. Any ideas?

 

Stop replacing parts at random!

What code, exactly, did you get?

Remember, problems can arise from connections and wiring too, not just parts.

I bet when you try to "reset" the ECU, it actually does reset, finds a fault immediately, and turns on the "Check Engine" light. The "Check Engine" light will not go out of the problem is still present.

Have you checked the TPS adjustment? http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

 

so it reads to me like u are getting a TPS error code, and are doing everything expect addressing the TPS code to get rid of the code.... am i correct or have i missed something?

 

TPS, is short for " throttle position sensor "...

I don't know this code number off the top of my head right now, but. Most commonly it is the IDL (idle, throttle closed) signal at fault..

Address the codes first, if you still have issues at cold start you can continue troubleshooting. You can't rely on it to run as expected with trouble codes present it typically buts it into a fail safe or limp mode were it assumes various things..

 

I've checked the TPS. And according to the settings on here, I used my multimeter and I've gotten it set right. The only thing, where it connects together, it doesn't lock together, at the plug. I've checking the wiring, and it is cleaned good, with no broken wires that I could find, made sure the connectors were all cleaned. Now, when I check the codes, it's throwing a 4,5,7, and 11

 

Did you just buy this truck??

Ok if this is the case you just need to work through things not uncommon to put $1000.00 in parts in

It was fine and all this started When??

At any time is it possible your ECU got water in it or Took a massive Voltage spike ??

You know welding without disconnecting the negative battery cable .

Clean the Battery ground to the block Clean the ECU ground on the right side of the intake .

Get to much Dielectric grease on that you don`t have a good connection remember dielectric grease in non conductive

 

I've had this truck for many, many years. This problem started about a month and a half, or two months ago. The ECU has never been gotten wet, since I've had it. And I've never welded on my truck. I just put a small amount of dielectric grease on the places I've used it on

 

Actually, why I started working on the truck in the first place, I was just going to tune it up. You know, new plugs and plug wires, stuff like that