[B-man]

First check for codes. Failure in either the circuit or temperature sensor will show code 21, 51, 61 or 116, 117, 118.

• Unplug the harness connector.

• 
  First, check the signal voltage at the connector with the key on, engine off. Should be approximately 5.0v.

• Then, check the resistance of the sensor cold. Should be between 58,750 to 40,500 ohms.

• Plug in the harness connector and warm up the engine to normal operating temperature.

• Then, unplug and check the resistance of the sensor hot. Should be 3,600 to 1,840 ohms.

The Haynes Manual outlines testing for all sensors.

SeattleFSB, Thanks for the information. I can do almost all of that. The one thing that I have put in bold print is the main culprit. I can go by the gauge inside for warmup, but, I am not sure if it actually warmed up. The idle stays at the same RPM's (650-700) from cold start up to when "warm". We have rechecked the timing, it is at 13 TDC. Should I have it at 10 TDC for all troubleshooting?




When I first completed my MAF upgrade. I got DTC 118. But, with only repinning a new harness and installing my fender mount remote IDM, as well as repositioning my spark plug wires, when I run codes, it is gone?

Doesn't make sense to me. Truck still doesn't know when it is cold, so it doesn't have the "warming up" stage with the higher RPM's to then return to normal idle. Temp gauge seems to work just like before in the rig. Gets hot, thermostat opens up, temp level goes down.

Codes had been run KOEO and KOER time and time again. Only code still is DTC 136. HOS2 sensor always lean. O2's have been replaced with new 1995 O2's. I am going to check volts and resistance on both of my connections today. I hope I am not confused, but, I thought I read some where that if the ECT is bad or anything, it will cause the PCM to "think" the motor is warm and at normal working temp.

I have replaced all my green , red , yellow lines with straight up vacuum lines. The truck will still sometimes lope and stall at idle.

I have a few tests that still need to be done. Got some other personal shit going on so, I haven't been able to get to it. But today, I should be able to.

It also hit my that I forgot to mention that I have antifreeze coming from between I think what is the timing cover and block. I saw it first on the right hand side coming down the block, at first I thought it was coming from between my block and heads. I don't think so now because I have two nice puddles on each side of the the timing cover. I topped off my radiator before I started up the rig after my MAF upgrade. That is when I got the DTC 116 code. I don't know if that has anything to do with my ECT, unless it is rusted out now? I am digging into this problem today.

I also hope to be able to:

Test the fuel Pressure.

Test the MSD Coil. I think it has been on there for about 3-4 years? I am not sure how long they last. But, that has been a thought as to being a culprit for a bit. Just didn't "think" it would be.

I do apologize and appreciate your guy's patience and tolerance with me. I am so freaked to start it up because I am afraid of me messing the motor up. I can in no way afford to rebuild another motor. LOL , Meaning my Bronco would sit, and that would just kill me. LOL. Kills me now looking at the ol' sob in the driveway, while I jump into a friggin minivan to work. LOL. Guess you don't know what ya got until it's gone.

I know one thing. When and if I ever to put another motor in. It will be a straight up stock 351w. LOL. Maybe just a cylinder bore and headers. that is it. LOL

 

[B-man]

I have checked the voltage on my ECT connector. It is 4.62 volts

My ECT cold is at 22.00 ohms? I am not sure what this means?

I have a pic of it below. Am I testing it incorrectly?

 

[B-man]

I guess I need a new ECT. I am also grabbing a new Thermostat, I don't think my last one was any good.

 

[B-man]

I check another ECT that I had bought new. I got the same reading? Confused here.

 

[B-man]

You can test voltage on the ECT sensor? I did that on the connector from the PCM.

That is a cool shot there. I don't have a programmer yet, so, I dont' think I can hit that up yet.

 

[B-man]

Thanks for the information guys. I will get on this!

 

[B-man]

UPDATE

Been a while, But, still need some help from the folk who know a hell of a lot more then I do on this stuff.


I replaced my ECT on a whim, Bought a Motocraft. RockAuto.com is THE best site ever. Thanks Sig!:thumbup

Fixed my warm up issue I believe. THe idle actually raised up when cold and mellowed when warm.

I only still threw one code. That DTC 136.

The only thing left to do is check Fuel Pressure and my coil.

I know the fuel pumps whine a little, but, mine is singing pretty... Guess I will find out after the Fuel Pressure test, which, hopefully I can do this week.

 

[B-man]

Whining fuel pumps are common with the Bronco. Did you recieve the DTC 136 after you cleared codes?

Yes, I cleared codes and got the DTC 136. I was testing the rig driving it, CEL came on and then turned off for about 45 seconds, then back on.

I was aware of the fuel pumps whining, this one is just real loud.LOL., Grasping at straws I guess.

I was about to start a thread on this. I have a 1992/302/E4OD. Since I got it, the temp guage has never reached operating temp. It stays on the "cold" line until I start it, then drops below the line. Well, I want heat, so I replaced the ECT, and it still doesn't move from below the line. Now sometimes, it's hard to start, almost like it's not getting fuel. I have to give it gas to get it to start, then it idles rough for a minute till I start driving. And it stalled on me today as I was backing out of a parking spot. Started back up no problem. Pulled code 116=ECT out of range. I checked the volts at the connection and it was good, at around 5volts. Checked resistance, and both the old and new ECT are within spec. I thought the connection might be bad, so I squeezed the female pins together a little, and still no change. Coolant level is good. I'm thinking the thermostat is stuck, or even the previous owner took it out. Any other ideas?

I had a similar problem like yours. But, my issue was the truck PCM would always read my rig as "warmed up", even when it was still cold. I replaced the ECT and Thermostat and cleared that up.

 

[B-man]

I don't know if anyone is still checking it this thread. Hope, I don't want to start another thread.


Every once in a while the CEL will come on, then go out. I know that I had the code DTC 136 (still have it) and it is puzzling me why this CEL is doing this.

I have been putting around the rig around town. It warms up, I drive it for about 10-15 mins, on comes the CEL.

Then, another 10 mins later, it's off.?

I have pulled voltage from the 02 sensors when hot, On the driver's side. I didn't pull much volts, like .078 or something like that.

Passenger's side , I pulled a .223v..

i am new to the multimeter, so, I need to recheck these later today. but, is it odd that my CEL comes on and goes off?

 

[B-man]

Thanx Seattle.

I think my deal now is I need to do the rest in a tune of the PCM. I will check the voltage again tomorrow. I might have a fouled O2 as well.

 

[B-man]

Yeah, wow, this is an old thread. On my old Bronco that had an untuned stroker motor in it. I just got done replacing wiring and installing an E4OD in my 88.. It had a C6 before. ..

I can't remember what the outcome was because I ripped out the motor and put a stock motor in , then sold it. Sorry.