Strange

Storm Grey · June 10, 2003

I had been babying my truck for the last month or so trying to get better gas mileage, you know 16-17 mpg. The other day I stomped on the gas at a stop light to turn the tires a little and I got nothing. It just kind of slowly took off. I ust to be able to turn the tires from a dead stop if I wanted to but now there is no way. It also feels like it shifts down allot more and has to fight to stay at 75 mph when I set the cruise. My service engine light is not on, and there are no other messages in the message center that have came on. I am really annoyed by this and want to fix it ASAP but have no idea where to start. I am wondering if any of you have experienced a similar problem or have any ideas. I am having my catalytic converters tested today but from talking to a few people they do not think it is the converters. My truck has around 80,000 miles on it with the 5.3 liter. I had my muffler taken off and a high performance glass pack put in place of it about a year ago. Any help would be appreciated. Please help.

I have made no new modifications for the past 6 months.

Taaaaaaahoe? · June 10, 2003

Did you happen to put larger tires on??

Mike

lmeier · June 10, 2003

I thought the Transmission on my Suburban was slipping, so I took it to the dealer. They plugged it onto their scanner and it came back negative. I wasn't impressed with the get-up-and-go of it either.

The technician said that newer transmissions (I don't know what year this started in) can learn your driving habits and will program themselves to that habit. If you've been babying it for a while, it may have learned that and programed itself accordingly. If this is the case, you can go to the dealer and ask them to re-set the transmission memory settings. You'll have to re-teach the transmission your habits.

Just a thought.

Layne

seadoons · June 10, 2003

I am in total aggreance with the previous post. These vehicles will learn your driving habits. If the truck got used to you not getting on the gas at all, and then all the sudden you jam on the gas, it is going to know what to do. If you keep doing that for a while, it will probably re-adjust to that driving style. Good luck to you!

Taaaaaaahoe? · June 10, 2003

if its like other cars I have had you can disconect the - neg batt cable for a while and things will reset.

However I don't know that the computer will compensate THAT much...

MIke

JonesNTN · June 10, 2003

1. Check the Air Filter!

2. 80K miles, you are probably due plugs and wires.

Storm Grey · June 10, 2003

I have babied it before to get good gas mileage and it never did this before. Also if this is the case then why would it have such a hard time holding 75 mph with the cruise set. It constantly kicks down for the smallest slopes. It has never done that before either.

Don't get me wrong I appreciate the feed back but it has been two weeks like this and I am just frustrated.

I don't want to take it to a dealer and have them spend three hour on it just to find the problem.

Thanks for all the info.

I did just clean my K&N Filter but plugs and wires have never been changed. Could Plugs and wires cause this type of problem?

JonesNTN · June 10, 2003

Definately so. Pull a couple of the plugs and check their condition and Gap. Make sure the engine is cool to the touch before attempting to check. Wires should be ok, but if you change the plugs out, you might as well replace the wires also.

Storm Grey · June 11, 2003

Catalytic Converters checked out fine. I guess I will look into new plugs and wire. Any suggestions on what brand?

Also any other suggestions on other things that could be causing my problem would be appreciated.

JonesNTN · June 11, 2003

Check this thread

k1500chevy97 · June 11, 2003

I guess I will look into new plugs and wire. Any suggestions on what brand?

AC Delco

rtbrick · June 11, 2003

You didn't happen to apply too much oil to the air filter when you recharged it, did you? Kinda like when an air filter gets wet (had it happen to a friends old beater car). Has your gas mileage suffered?

Does the PCM really read your driving habits and adjust and compensate for it? Sounds goofy to me. What if you needed to hit the gas in an emergency situation and couldn't because the computer would not allow it? Doesn't sound right to me.

Bish · June 11, 2003

Believe it or not, the PCM definitely learns your driving habits. I reset mine every 4-6 months and each time I notice significant differences. Most obvious is downshifting. Right after I reset, the tranny rarely downshifts unless I really lay into the pedal. After a few 100 miles, it figures out that I'm probably gonna floor it to get it to downshift anyway so it might as well do it sooner rather than later. Definite shifting diferences.

As for plugs, I like the NGK tr-55 copper plug. Had a couple platinum discs fall off my stock plugs. Plus I think a copper core gives a "brighter" spark. Only downside is changing them every 30K. Have seen a few people strip plug threads when they wait 100K beore pulling a plug out. I also used Taylor wires.