Issues... Issues... Issues

[PetroleumJunkie412]

Only one surefire way to find out

 

[RonD]

O2 sensors can't work until they get above 650degF, so computer ignores them and stays in open loop until they start to generate voltage(O2's generate their own voltage), that can be 4 to 8 minutes after cold start
Yes, if you unplug O2 sensor computer will run in open loop
O2 sensor is not used at idle, or at WOT(wide open throttle)

One test you can do is to run warmed up engine at WOT, if it runs better at WOT then you could have an O2 sensor issue

 

[Nez'sRanger]

Well, I ran it unplugged today... No difference... Well, it took a little longer to start surging, but once it did, it was almost worse than with it plugged in. Then again, that may be from the humidity in the air from the rain...

 

[Nez'sRanger]

I went to the local salvage yard and got a whole wiring harness from another 89. I am currently taking all original shielding off, and double checking it and rewrapping it. I found a few problems... the relay connector wires were bare, up to an inch from the connector itself. I'm sure that could cause issues... I'm also wondering if I have a lot of that on mine.
I also noticed the wires were somewhat melted together on the tfi branch of the engine harness (the rearmost 8 pin round connector on the passenger valve cover). Some of those were starting to bare. I think I figured a few of the reasons it's at the scrap yard... I'm looking forward to the 4 day weekend to install it and see what condition mine was in.
At this point, the only thing I can imagine is that jacking my motor up caused some bare wires to contact for the first time... Fingers crossed.

 

[ecgreen]

I will say this, you are the most persistent man on earth! I can't wait to see how this turns out

 

[Nez'sRanger]

I will say this, you are the most persistent man on earth! I can't wait to see how this turns out

Well, not only is this my daily driver, it's also my baby. I gotta fix it up good so I can actually get to put various mods on it.

 

[PetroleumJunkie412]

Well, not only is this my daily driver, it's also my baby. I gotta fix it up good so I can actually get to put various mods on it.

Let me know if you need parts!

 

[Nez'sRanger]

Ok, got my new harness in today. While I had it ripped apart, I remote mounted my tfi with a nice heatsink from an Aerostar. As far as I can tell, problem solved!

 

[Paulos]

Ok, got my new harness in today. While I had it ripped apart, I remote mounted my tfi with a nice heatsink from an Aerostar. As far as I can tell, problem solved!

Cool. Glad you got it worked out, and thanks for the follow up.

 

[PetroleumJunkie412]

So you're back up and running??

 

[Nez'sRanger]

So you're back up and running??

Yep! It's running nice. Idling like a champ!
The check engine light came on. Gotta get the flash codes. Even when it had serious problems, it never threw a code, so maybe that wiring is fixed now too! Haha!

 

[Nez'sRanger]

Yeah... The tps worked it's way unplugged during my test drive. It's good now! Haha!

 

[Shran]

Interesting. I wonder what the problem actually was then - maybe a combination of factors.

 

[Nez'sRanger]

Interesting. I wonder what the problem actually was then - maybe a combination of factors.

I'm gonna go with something in the wiring harness, just because it never showed symptoms of a tfi problem, and because it only started misbehaving after I lifted the engine. I don't have the will power to take apart my old harness anytime soon, but I have it in a bag in my closet. Someday I'll let my curiosity kick in, and I'll find exactly what went wrong.
Until then, I gotta save up for a new catalytic converter! Between the previous owner blowing coolant out the exhaust, and now me blowing untold amounts of unburned HC's through it, I can literally feel its restriction through the gas pedal!

 

[Paulos]

Until then, I gotta save up for a new catalytic converter! Between the previous owner blowing coolant out the exhaust, and now me blowing untold amounts of unburned HC's through it, I can literally feel its restriction through the gas pedal!

Do a search for how to clean a catalytic convertor. A while back I saw some YouTube videos on the subject, but never tried it. If it worked, it would be cheaper that a new one. Here's one by Scotty Kilmer. Just a thought.