REndi500
06-20-2023, 06:41 AM
Hey yall, I joined up to dig into your xml/bin repositories. I figured I could use this mandatory intro post to fish out solutions for my truck. I'm getting setup with Tunerpro to help with diagnostics, but I'm open to ideas in the meantime.
1994 Chevy k2500 7.4L 4L80e, just rolled over 100k
All new sensors, senders, and everything else on the outside (IAC, MAP, temp, EGR, O2, TPS, ISC...); new fuel pump (whole in tank unit) and filter; new distributor, coil, plugs, wires; the list goes on.
Fresh rebuild on the transmission. It's been back to the shop for several checkups under warranty - they are positive there's no issue with the transmission.
Timed to 4btdc with the timing wire unplugged - idles correctly at ~19btdc.
Vacuum looks good over 18 throughout rpms.
No DTC's being stored.
The Cats been cut and it has a new aftermarket radiator, but otherwise bone stock.
The main issue is that it tries, and occasionally succeeds, to stall when put in gear at idle. If it catches itself before stalling, it will bounce RPMs between ~200-600; it idles nicely at 800 in park or neutral. When driving and coming to a stop it will act perfectly normal until the wheels have completely stopped, then start bouncing the RPMs 200-600. When under load, like on the floor uphill, it seems like it will stick in 2nd and 3rd gears, kinda stalling around 3000-3500 rpm until I let off and let it shift. If I put it down on flat ground it'll shift at the red with no stalling and pretty smooth transfer like you'd expect from a fresh tranny.
My last guess was the TCC, but it seems to engage/disengage normally when driving. If I put the TC in neutral it will still bog and bounce rpms when I shift the trans into gear, but not nearly as badly.
Open to ideas. It runs great otherwise with all this new stuff, I'm just too neurotic to let it alone with a small issue.
1994 Chevy k2500 7.4L 4L80e, just rolled over 100k
All new sensors, senders, and everything else on the outside (IAC, MAP, temp, EGR, O2, TPS, ISC...); new fuel pump (whole in tank unit) and filter; new distributor, coil, plugs, wires; the list goes on.
Fresh rebuild on the transmission. It's been back to the shop for several checkups under warranty - they are positive there's no issue with the transmission.
Timed to 4btdc with the timing wire unplugged - idles correctly at ~19btdc.
Vacuum looks good over 18 throughout rpms.
No DTC's being stored.
The Cats been cut and it has a new aftermarket radiator, but otherwise bone stock.
The main issue is that it tries, and occasionally succeeds, to stall when put in gear at idle. If it catches itself before stalling, it will bounce RPMs between ~200-600; it idles nicely at 800 in park or neutral. When driving and coming to a stop it will act perfectly normal until the wheels have completely stopped, then start bouncing the RPMs 200-600. When under load, like on the floor uphill, it seems like it will stick in 2nd and 3rd gears, kinda stalling around 3000-3500 rpm until I let off and let it shift. If I put it down on flat ground it'll shift at the red with no stalling and pretty smooth transfer like you'd expect from a fresh tranny.
My last guess was the TCC, but it seems to engage/disengage normally when driving. If I put the TC in neutral it will still bog and bounce rpms when I shift the trans into gear, but not nearly as badly.
Open to ideas. It runs great otherwise with all this new stuff, I'm just too neurotic to let it alone with a small issue.