Urambo Tauro

Well, that's why I was hoping you'd test the sensor, instead of spending money on replacing it outright. The new one's probably not bad out-of-the-box, but you never know, these days...

Of course, the ETC might not even be the problem at all. But it's a simple enough thing that really should be ruled out first before moving on to the next item. Or else you'll just be on a wild goose chase. (FWIW, the ECT sensor directly affects both cooling fan operation AND engine management, so the sensor and its wiring really need to be functioning properly here.)

Other basic things to be on the look out for before delving too much further into the issue:

• Battery must be fully charged (as well as hold that charge AND pass a load test)
• Battery cables, connections, and other ground paths must be in good condition & properly fastened
• Alternator must maintain battery voltage when engine is running

What's "vet"? Were yout trying to type ECT? If so, I'm not sure why the fan would activate with the ECT unplugged. I would imagine that the high resistance from the lack of a connection there would simulate a VERY cold engine, one that didn't need the fan to be on at all. (But it's good to hear that the fan motor works, though...)

THE 1

Not sure what to do now ? Is it necessary to clear all codes or something ? I was pulling 4.7 at the connector to the ect sensor with the ignition turned on,is this ok ? Let's say the ect sensor is not the problem,what else could it be ? I've gone over all vac. lines and see no issues there. A code reader I have shows no codes? I'm truly stumped,but am convinced it's something simple ? Thanks for your help. ☺

Urambo Tauro

4.7 ...volts? I don't know what you should expect to see at the connector. If you're confident that the ECT sensor is working properly, then double-check your battery, cables, charging system, etc. and make sure that the car's electrical system has a good source of power. I really don't want to suggest that the PCM is bad until you've covered the basics first.

If you had codes, I would say read them before clearing anything. But if you don't have codes, then there's nothing to clear.

THE 1

Borrowing a good code reader tomorrow, I will see what pops up. I'm wondering if the computer box is going,as it seems to be getting worse ? I've read that their should be around 5.0 a at the connector with key on,I'm assuming 4.7 would be ok ? I'm not that experienced with modern F I systems and ALL the frickin sensors! No "check engine" lite ? It seems to be misfiring ,no power ! 😕 Thoughts ?
Thanks

Urambo Tauro

Yeah I can't say for sure on this application, but 5V does seem to be a typical voltage for sensors, so 4.7 is probably close enough. So that tells us that voltage is getting to the sensor, but it tells us nothing about whether the sensor is reporting the correct temperature values back to the PCM. I'd feel better if you actually tested the sensor itself just to make sure that it wasn't bad out-of-the-box.

There may or may not be stored codes, but if the check engine lamp is not on, you should still see it briefly illuminate when the key is first turned on. That'll at least let you know if the bulb is working.

The ECT and PCM are the only things I can think of that affect both fan control and engine management. If neither of those items ends up being faulty here, then we will have to pursue your fan problems and the engine running problems as separate issues.

THE 1

At the risk of sounding really stupid,I'm assuming the " pcm" is the "computer" under the kick panel on pass. dude ? Does the problem in having sound like something that would happen if a pcm was going bad ? Also, would a pcm going bad throw any specific codes ? Thanks

Urambo Tauro

Yeah, it's the computer behind the kick panel. I know very little about diagnosing PCMs, so I'd encourage you to eliminate everything else first before spending that kind of money.

THE 1

Ok, well found out it's OBD 2 for 95 6cyl. Borrowed a reader and come up with no codes ! Engine runs like crap still ? Interesting note is that the reader shows the timing at idle varying between 17 and 21 degrees ??? This can't be right ? Any thoughts ? Thanks

THE 1

Still having issues with the engine ! I'm at a total loss ! Engine barely runs does not smoke,gets hot fast,fan won't come on unless disconnected from ect. , here's the kicker, throwing NO codes at all! Engine lite not coming on either? How is this possible? Is this indicative of a going bad or bad PCM ? Any thoughts appreciated greatly ! Thanks

Urambo Tauro

Hey, welcome back. Y'know, it just so happens that since your last visit here, I had to buy myself a big ol' book to help diagnose my own rough-running car. So I might be a little better-equipped to help you out now. Unfortunately, the book doesn't cover OBDII vehicles. But you don't have any codes present anyway, and the basics should still apply...

So unless someone else chimes in with another idea of how your symptoms might be related (head gasket comes to mind, but I don't want to jump to conclusions), we'll have to pick one symptom and follow that symptom's flowchart. In the meantime, please make sure that you're not overlooking something simple. Check for any loose electrical connections, bad vacuum lines, air cleaner/intake tube restriction, and make sure your fluid levels are good (especially coolant). Oh, and make sure that battery's all charged up too.