Newbie Old Guy

[boomer49]

Hi all, I got into car stuff as rookie 'mechanic' back in 1965. Yup the good old days of Super Cars. Worked at a Pontiac-Buick-GMC dealership in northern Wisconsin. Left that career many years ago and now do computer stuff but keep my hand exersized by working on my own and family vehicles. Purchased a Scanner a couple years ago and even with it's limited capability it helped. Lately though I have been running into a weird situation with my Red(this is important,LOL) 1999 GMC Sonoma ExtCab 4X4 auto w/4.3 in that while driving with steady to light throttle and with or without cruise, the engine RPM will jump up 100 to 250 RPM then drop back down. It does this even when not in full closed loop. It acts like the lockup torque converter is unlocking-locking-unlocking-locking, etc. My scanner doesn't show any codes but doesn't have the capability to do the trannie. One observation is that the percentage for the TPS, which normally displays 4-8% while driving, will jump up to as much as 20% at the same time as when the RPM jumps up. So I am planning on getting a Snap On MT2500 with the appropriate cartridges
so I can perform a major of the diagnostis including transmission.
Anyway, looking forward to reading the comments in this site.

Rick

[ROKTMAN]

Rick,welcome to THE place to be.

Sorry I can`t help you on the codes.I`m no mechanic...LOL

[boomer49]

Originally Posted by ROKTMAN

Rick,welcome to THE place to be.

Sorry I can`t help you on the codes.I`m no mechanic...LOL

Thanks Dave, lots of interesting threads in here.

[jamz]

Welcome to GMPT, glad to have you here. If you have any questions relating to the website let me know.