1996 V6 5VZ-FE engine bogs to stalling when warm

I live in new england, and I bought this thing off someone who moved up here from texas a few years back so it's basically rust free. It's not the prettiest (right now) as the paint/clearcoat is in rough shape, but I have so much love for this guy.

 

So I just tried this, it did not seem to fix the bogging issue. What was interesting is the battery light did not come on but the check engine light obviously was. I imagine that the battery light didn't come on because the battery still had a bit of a charge to it. But it does seem thankfully that this is not the culprit.

I also tried to pull codes off of the OBD1 port in the engine bay as outlined here: https://www.2carpros.com/articles/t...finitions-and-code-gathering-method-1990-1995

But jumping the two ports did nothing to the CEL.

 

Actually the battery light should have come on. But that’s really not a big deal right now. The jumping of the pins didn’t apply to the OBD II systems. That was a carry over from previous years. As I recall, you could access other computers from that connector (I think ABS and cruise) but I can’t really remember. I’m pretty sure by 97 or 98 that OBD I connector was gone. By that time we were accessing everything through OBD II.

 

Got it makes sense. I was hoping that was a way to get codes at the OBD2 was unresponsive. Right now I'm hitting the truck up to try the ECU freezer trick. See if that does anything. One thing I did notice though, when checking from the OBD readers emission test readiness, the catalytic converter and One other metric never came through as ready. Someone in another thread said that this could be related to the catalytic converter

 

The most curious thing about your problem is that when it goes to running bad, you lose communication with the engine ECU. That was exactly the way that Camry would act when the Engine ECU would go on the fritz. And it would store no codes.

 

The Catalytic monitor won’t run till it is driven and O2 sometimes takes a while too.

 

Some of those monitors don’t even apply to your truck (like a/c and secondary air) In fact, some of those engines didn’t even have an egr valve and some did. On the factory scan tool, you had to input whether it had egr or not.

 

OK so new development. I tried the freezer trick, truck bogged, pulled the ecu, threw it in the freezer for 5 minutes, brought it back out and threw it in the truck. No more CEL. I idled the truck for a long time this time, 20 ish minutes. No issues. I take it out, drive a few loops around the neighborhood, nothing. Then, as I'm reversing it back into my driveway, the truck just dies. I start it back up, immediately dies again. I get it back to it's parking spot eventually, and I turn it off, put the key to "on" to see if I can read codes but nothing is coming up. THEN i noticed the CEL was flashing, and I was hearing a clicking noise - then i took the following videos:
https://imgur.com/HJcUAir
https://imgur.com/oivv1F9

 

When it’s all glitchy like that, put the ecu back in the freezer and chill it again. See if the problem stops again for a while.

 

The clicking is probably caused by the ecu spazzing out and pulsing the grounds to the vsv (vacuum switching valve) solenoids.

 

OK I will try again tomorrow - if the chilling makes it work again for a bit, is it safe to assume it's the ECU at that point?

 

It certainly makes it a prime suspect. Unfortunately any more testing is going to take some pretty specific stuff.(oscilloscope,multimeter, power probe) It is unusual for us to have ecm problems, but not unheard of. The only sure way is to use a known good computer, but finding one is going to be the issue.

 

Got around to testing this again today, started the truck. Took about 10 minutes to get up to temp. Pulled the ECU. Put it in the freezer for about 10 minutes. Put it back in this time it started running crappily again after maybe 2 to 3 minutes, and the engine is/was a bit below what would be considered the running temp.

 

When you changed the spark plug wires, did you change the boots under the coils?
They are actually like 3 little wires and will short to the cover when they split and make a click.

 

I believe so, this is what I used: https://www.rockauto.com/en/moreinfo.php?pk=5472297&cc=1278930&pt=7224&jsn=13
With these plugs: https://www.rockauto.com/en/moreinfo.php?pk=3153357&pt=7212&jsn=10

 

Just closing the loop here because I finally fixed my issues. It was a bad cam position sensor and I also replaced the ECU because I couldn't get check engine light codes.