gsjimmy

Well got the trans issue sorted out, and now a new issue has shown up.

First the oil pressure gauge quit working (45 psi to 0, not moving). This was an easy fix, pinched pink wire. Gauge works fine now.

Then the engine started acting goofy. Getting a spike in RPM to 3000 range, then drops to 900, then 550 and eventually dies. Restart and same thing over again.

Diagnosis is pointing to the throttle body as the reader says “No codes found”. So am I looking at the TPS switch, IAC, complete throttle body or an air leak? This engine was running fine and taking throttle. Idle of 750 rpm.
I had to tear down the front end to pull the trans and replace the bell & converter. I don’t see anything obvious, like an air tube that is leaking unregulated air into the system.

Another is that the truck is running rich. Like burns your eyes rich. So, I think this may also be related to rough idle and other symptoms.

Combo: ’99 5.3, 2002 LS1 cam, ’98 F-body manifolds into a Y-pipe. Otherwise all stock
Trans is a 4L60e original to the S-10. Going to use it until……

So I need some ideas.

TXjeepTJ

iTrader: (8)

New issue? So it started AFTER you fixed oil pressure wiring and the transmission?

I'd definitely look at everything and anything that you could have touched when fixing the two first issues (or whatever issue you fixed, and then this issue started)

Darth_V8r

iTrader: (4)

Running rich will cause idle surge badly. So before you start chasing throttle stuff, check your oxygen sensors and wires and check your exhaust for leaks. Very possible something got amiss in the exhaust after dropping tranny.

gsjimmy

Well the exhaust is sealed up. Only possibility is the short pipe at the y-pipe to cat. The possible leak would be after the O2's (like 6-8 inches past the O2 on the pass side).

I did replace the IAC valve and TPS last night, no change. These were original to the engine, figured that this will eliminate obvious issues with possible failing sensors.

Truck isn't pulling any codes, so an unplugged O2 seems to not be very likely, but I will check the pass side again to be sure. I have 2 more new O2's if that proves to be what's wrong.

TXjeepTJ

iTrader: (8)

Did you disconnect any ground wires when removing the transmission?

gsjimmy

Well 3 sets of ears are better than just mine. Got the issue fixed now. It was a missing gasket at the EGR inlet. I couldn't get in front of the truck quick enough to catch it. Pulled the spare off the shelf and voila, perfect idle and takes throttle again. Tonight I will finish up the punch list and get it aligned. Should be on the road next week.

Darth_V8r

iTrader: (4)

Nice job! And thanks for getting back and completing the thread too!