1999 Silverado

99 Silverado, 4x4 4.8 V8 with 88k. Occasional (10 times in 4 years), I get what amounts to disengagement of the tranny at idle.

I've been stopped at a light or sign, attempt to pull out, only to have nothing, but in a split second, I get momentum. Not a slapping of the tranny, just "nothing", then you can feel the slight engagement and its fine. This is very intermittant, but odd. My brother in-law's Tahoe did the same thing.

I also have a very fuely smelling startup. Doesn't give a problem starting, just notice raw fuel smell.

At 88k, what detail of tune up should I be looking at? Running ok, but could be much better.

Thanks for any input.

i have the same problem, it happens about once in a blue moon, maybe 1 or 2 times every 2 months. its like its not moving and gets caught. i have already had my tranny rebuilt, and it has been serviced and it is fine, and then my rear end has also been replaced and that shouldnt be the problem, so im curious if anyone knows what might be causing that.

There is quite a bit of communication taking place between seven computers in your truck. This problem could be related to data packet errors between the engine and transmission computers. ABS computer error may also cause transmission errors.

Is there by chance any error or warning lights such as the engine, ABS or other illuminated?

Have never seen any LED, there are also no codes being written, I've had them checked. It's freaky. It just happend again this morning, backing out of my driveway...

I had this happen to me 9-21-04, very weird, I was stopped at a light and it did exactly what you said your's did. I drove straight home and checked the fluid level and it was ok. Not sure what the deal is. I have a 99 2wd, 83k.

fuel pressur regulater, drivers side motor on the fuel rail, pull the vac line if there is gas in the line replace about $50.00 at auto zone, runs like new

HOLY OLD THREAD BATMAN!:grinno:

:slap:

It is not the fuel presure regulator.. I have replaced that for other reasons and I did still get the same syptoms they are talking about.
It is almost like it is trying to start in high gear or something then shifts down after a sec or two.
I agree, I think there is a communication error between the tranny and the engine.

My friend gets the same problem in his silverado, but it only happens when he doesn't warm up the truck