Software recomendations

[4X4HIGH]

Just keep in mind that HC's are unburnt fuel. Either the thing is running rich (from the BLM's you displayed this isn't the case) or you could just as easily need a tune-up. Also, if you have a CAT on there that is old and if the HC's aren't too far off a new CAT will clean up the HC number (that is what the CAT is for actually).

 

[pmpski_1]

Right - the HCs are not that far off, maybe 20 PPM. I looked up the emissions history on this vehicle and the last time it was checked was 07. The idle HC was 70 at that time, vs 240 something right now. Based on the oil change sticker (and the date on the filter), it has been sitting a lot since 07 and has been driven less than 2500 miles. I'm wondering how I can determine if the cat is bad. I see with the OBDII systems they have an 02 sensor behind the cat as well, so it's easy to tell.

I've got a new cap, rotor, plugs, wires, t-stat, and will be going through the tune up and setting the timing. This software\OBD1 stuff is just fun for me so I jumped on it.

BTW, I found some basic BLM info here: http://lt1howto.com/articles/pcmtuning.htm

I'm sure there's something more comprehensive out there, but it got me started.

My wife is getting tired of me telling her how much I love this truck and about how much fun I'm having with this.

 

[4X4HIGH]

Have you changed the oil before the emissions test? If not that could also lower the HC number.

 

[pmpski_1]

Have you changed the oil before the emissions test? If not that could also lower the HC number.

Yep, that was the first thing I did.

 

[pmpski_1]

Here's a run I did this weekend. Thoughts? I have a decent book that I'll use to go over all of my readings over the run to see if anything sticks out as being abnormal.

 

[dave w]

Here's a run I did this weekend. Thoughts? I have a decent book that I'll use to go over all of my readings over the run to see if anything sticks out as being abnormal.

Overall I think the data log shows you are mostly OK. I'm sure you know this already, the ideal BLM average is 128. The usual acceptable BLM range is + / - 2 or between 126 ~ 130. Most all the BLM's posted are in the acceptable 126 ~ 130 range. At the upper RPM's the BLM average is showing a touch lean, or numbers higher than 130. The only way to correct for BLM averages higher than 130, or lower than 126 is to change the programming in the PROM ( VE Table).

dave w

 

[pmpski_1]

Thanks Dave! That is what I thought when looking at this table. The 134 avg at 1800 60 worried me a little bit because it seems like it's past the upper end of ok, and it's an average. That's obviously not the problem for my emissions test though