My 99 Chevy Silverado 1500 needs your help!!!

[duckthehoward]

Well, Fist off let me thank you for taking the time to look at this thread, so Thanks! Hopefully someone will have some sort of an idea about what my trucks issue is.... Other than the obvious, and you'll get that joke in just a few.... anyways here's the problem.

'99 Chevy Silverado 1500 2wd 5.3l vortec with 231,000 miles, engine has only 82,000 mi. and the transmission has 23,000 mi., the engine that is in it was put in there about a month ago, after a few minor things the truck has been running flawlessly for about 2 weeks, that is until my pride got the best of me last night coming home from work.... I was doing a little hot rodding, messing with a newer Camaro and as I was doing between 45 and 55mph I meant to shift into neutral to rev my engine at the guy who was driving the Camaro, but OOPS it went into reverse instead... the tires locked up for a second as that is how I knew I had made a mistake, as the gear indicator light has been a bit haywire since the engine swap and takes it sweet time indicating what gear the transmission is in. I immediately shifted back into drive and as I did the abs failure lights came, about 30 seconds later I was closing in on a stop light so when I came to a stop I turned the truck off and restarted it, crunk up fine, no warning lights, no odd noises from the tranny, I thought I was safe.... about a mile down the road going through another stop light the truck decides to die. Now at the time I thought I may have been low on gas, as another thing that has been going crazy for a couple days is the fuel gauge, it's been really sensitive, dropping when going up a hill or even fluctuating if I happen to hit the gas harder than normal... turns out I was not low on gas as I added 5 gallons from a gas can which then brought me up to half a tank. The truck would not restart after adding the gas, it acted as though it was starving for gas, so I had it towed home thinking I had run it out of gas and the fuel filter was now trash or possibly the fuel pump, this morning I replaced the fuel filter, still no dice, I have tested every fuse and relay in the vehicle, trouble shot the MAF sensor, cleaned the IAC sensor, replaced the battery, inspected all connections that I can reach without removing any vital parts both on the engine and the tranny and still nothing.
The vehicle will start, catches just fine, but if the MAF sensor is connected within 5 seconds it will die, with the MAF sensor off it will take about 15sec to 1 min to die. If I try to give it a decent amount of gas it dies however if I nudge the pedal or the throttle body it bogs down at first then revs higher as I release either the pedal or the TB.... I have stumped about 7 people in my local area with this issue, one of them claims to be an ASE certified mechanic with 30 plus years exp. and apparently owns 2 of the same exact vehicles.... I am left thinking that maybe I fried my PCM somehow, I don't think it is my fuel pump as it cycles just fine however I will have to wait until tomorrow to rent the fuel pressure test kit from my local OTTERZONE. I figure if nothing else you guys will get a kick out of my dumbass decision to try and shift into anything other than D going forwards but I also hope someone somewhere may have some good advice they can give me on what to do next besides taking it to the dealer and letting them bend me over raw....
Sorry this was so long and again thanks for your help in advance!!!

[j cAT]

engine tranny swaps are usually electrical ground problems .. loose connections. other wiring would be damaged wires and insulation loom coverings removed causing chaffing on the casting metal along with not using the wire harness supports. PCM can get damaged from bad grounds .. also many electrical issues of the different circuits usually goes back to the grounds. if this all checks out it may mean the ignition switch may need replacing with this mileage. then the fuses should be snug and not corroded ..esp in the under hood fuse box.

[duckthehoward]

j Cat, thanks for your reply, as far as I can tell all electrical connections are good, I did the engine swap myself and made sure I used all harness supports, I will definately look into the ignition switch issue. The next thing I had planned to investigate was the fuel pressure regulator as it does show signs of gas coming out of the vacuum outlet that goes to the top of the manifold, then I plan to test the fuel pressure. I will be doing these checks this afternoon so I will update as I check things off the list... thanks again

[j cAT]

Originally Posted by duckthehoward

j Cat, thanks for your reply, as far as I can tell all electrical connections are good, I did the engine swap myself and made sure I used all harness supports, I will definitely look into the ignition switch issue. The next thing I had planned to investigate was the fuel pressure regulator as it does show signs of gas coming out of the vacuum outlet that goes to the top of the manifold, then I plan to test the fuel pressure. I will be doing these checks this afternoon so I will update as I check things off the list... thanks again

the fuel regulator leaking into the intake vacuum line will damage the converters.
you should have had some codes CEL...