tr55 or tr6 for my application?

[Robmnrd]

Yeah today I'm doing O2 sensors, I figure they're cheap and easy so I might as well try them out.

I guess I wouldn't be all that surprised if I fouled them after this whole fiasco. lol.

[Robmnrd]

Alright so I haven't updated in a little while, but the O2 sensors did not solve the problem.

I think it is time to shift my focus towards things related to variables that change as drive time increases. It seems like the problem does get worse the longer I drive and the hotter the engine gets. So what does that leave me with?

Coil - they are prone to heat soak issues (Usually those are no-start issues though I thought...)
Water pump temperature sensor - I've seen more than one post about the water pump temperature sensor going bad or being damaged and causing a slew of problems, all without setting off the CEL.
Opti? - I haven't really seen posts about it being a problem only when the engine is hot...and also most of the time it seems to be a problem under throttle/rpm and my problem is more with low rpm and high load.

I dunno you guys, this one is a tricky one. lol

[Robmnrd]

Alright guys time for an update!

After the O2s didn't fix the problem I went ahead and disconnected them and ran it in forced open loop and it seemed like it helped but after driving it like that again I think it's just running rich enough and with enough timing pulled that it's just kind of 'masking' the problem where as it's extremely obvious in closed loop. So (at least for the time being) I think that eliminates issues that could be caused by open/closed loop variables.

I noticed something else on this most recent drive that may or may not help; according to my battery voltage gauge on the dash the system (when hot) is only charging to ~12 (maybe less...it would help if the gauge had markings that made sense lol) volts. Since I did disconnect the alternator during all of this, do you guys think maybe there's a problem somewhere in the battery->alternator cable->alternator area? The voltage drops as temperature increases, maybe it's dropping low enough that it's causing trouble down low in the rpms where the charge isn't getting high enough and then increased rpms 'band-aids' the issue because it charges more completely? Seems like a little bit of a stretch but figured it was worth mentioning just in case.

[JoeliusZ28]

If anything that would be the other way around, higher rpms is a bigger electrical load. I believe alternators peak their charge production at an rpm well below redline, but thats just my own observations. Your theory is worth investigating though you may want to have the alternator tested if the connections check out ok. Alternator is nice and easy to get to on these cars

[Robmnrd]

If anything that would be the other way around, higher rpms is a bigger electrical load. I believe alternators peak their charge production at an rpm well below redline, but thats just my own observations. Your theory is worth investigating though you may want to have the alternator tested if the connections check out ok. Alternator is nice and easy to get to on these cars

Yeah I'm definitely gonna have it and the battery tested (it's about 4-5 years old now too, and if there have been charging issues I might as well get it tested too!).

Even though a new alternator is kinda pricey for what it is, I'd love it if something that easy fixed my problem.