old yellow won't start

[ronnieb]

Engine is a 2002 5.3L from a Tahoe transplanted into my '84.

Harness and computer were modified by Hanna and Jesse.

Ok here is what's happening or not. Tried to start it and it just chuggs. Thought it might be the injectors so it got all new ones, no change.
Pulled the coil pack connector on driver side and started, no change.
Pulled the plugs at this point and discovered that there was only 2 firing on the pass side.
Tested the coil packs and they are all good.
Checked the compression and all are 170-180.
Fuel pressure is 53lbs.
I don't have a code reader that covers this year model which would probably help for troubleshooting.

This engine is also a TBW and doen't appear to be responding.

Anyone, everyone, please help, I'm stumped.

[Gordonr1973]

This might be a dumb suggestion but checked your fuses?

[Gordonr1973]

Try this too:

Re: Silver Dollar

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Called the wife and kids out to the garage, for this glorious moment. when I tried to start the engine for the first time, it wouldn't start or run. after a few minutes of me cranking, and some cussing. They must of got the feeling that the show was over. cause they all just slowly went back inside. (iv seen this before.) So now Im thinking to myself and resiting the 3 basics all engines need. First I checked ignition, with my timming light. every cylinder was firing. Next, shot some starting fluid down the throttle body, and it would start and run till the starting fluid burnt up. I Then put my fuel pressure gauge to it. it had pressure to the rail. Ok! What the hell is going on here. I posted the question on the forum got so good suggestions, and asked my PCM programmer, Brenden at LT1swap, He suggested I check the injectors, they might be cloged or "stuck" from sitting.
So I took out the injectors and put one in the vice Poured cleaner into the top of the injector. Made a simple wire harness, one side went to the power on the battery charger. The other I dragged across the negitive clamp on my charger. this resulted in the injector pulsing open and closed very fast instead of just staying opening.



At first I dint hear the injector pulsing at all but after a few minutes i started to get some nasty stuff out of it.



I went ahead and did this to all the injectors, then soaked them over night in cleaner. The next day, i had to run to the parts store for new injector orings. The cleaner had swelled them. should have taken them off but was sidetracked. After the orings were in I put the injectors back in the rail. i have a OTC injector cleaner, that will pressureize the rail to bypass the fuel pump for cleaning purposes.


So I hooked that up and used the same trick as I did on the bench and fired one injector at a time, this time with 55 psi behide them.


Sprayed cleaner through the injector into a little catch can a.k.a. wifes storage container (she let me keep that one). did that to all injectors till it looked like i had a good spray pattern.



Put all the injectors back in and fired the engine. she started and ran. it was a little loud with no exhaust but it was great just to her in run.

[ronnieb]

Thanks for the suggestions.

I did check all the fuses, too include all the new ones added, all good.

I had thought the samething about stuck injectors and with 90k+ on the engine decided to just replace with new ones. Same issue, only runnung on #6&8 cylinders.

I'm off to the parts store this afternoon to buy a reader that will also erase codes and go from there.

One of my co-workers asked if I had a white or black connector on the crank sensor. Mine is black(24 point reluctor), the white is 58 point. He suggested I call Jesse at Wait4Me to see if he changed it from what it was?

What struck me as odd was when I pulled the plugs and 6 of the eight were still new, as in like right out of the box, and 2 were covered in soot.

More troubleshooting tonight and more to follow.

[ronnieb]

Talked to Jesse at Wait4Me, what a great guy, He can't change anything on the crank sensor, it's a different computer, different harness, so that's not the problem.

He did ask about the throttle plate, if it moves with the key on? Guess what, mine doesn't. Need a code reader for sure now. Jesse says it will do exactly what it is doing if the throttle is not responding. Either the TAC box is bad or the harness to the pedal.

So, more to follow.

[ronnieb]

Well some good news, I shot some starting fluid into the intake and it ran on all 8 till it ran out. I really don't like using starting fluid but it was the only way to check the coils and see if it would run and it did. This prompted me to check the power to the injectors and only 2 were getting power. Checked the new fuse box and although it tested good it wasn't. The connections were good enough to light a test meter but not good enough to power the injectors. When I unmounted it it actually fell apart. I took me time and puit it together correctly and now had power to the injectors. reconnected everything , hit the key and it started and ran on all 8!!!! yephee.

Now I have an engine check light and the throttle is still not working. Junk yard in the morning to see if I can score a TAC box and an OBD II connector.

More to follow.

[ronnieb]

Went to several junk yards and no TAC box but I picked up an OBD II and on the way home picked up a new scanner. Put it all together and hooked up the scanner, got a P0122 fault code, erased and it came right back. Says I have a low voltage at the TPS,
checked and had 5v where it was supposed be, now I'm lost. I really wanted to get the truck done, want to drive it to Pella IA in July for the Reserected Tin show, but if this keeps I may not make it.

[Cherub]

make sure its getting contact with the pins. I had the same issue with my TPS sensor. i bought a new one and still had the error. looked at the tps connector and one of the pins was stretched causing a loose connection. worth a shot.

[ronnieb]

Checked the pins all is good there. Went to the parts store to see about a new TPS and they are a non-service item refer to throttle body, can't buy one seperately. AARRG.

Any way did some more testing and this is the results.

TPS TAC
GRAY-4.98v 4.98v-pin2
GREEN-1.08v(5.08v unplugged) 1.08v-pin1
LTBLU/BLK-4.98v 4.98v-pin9

So that indicates harness and connectors are good, but is that the correct voltage for those pins?

anythoughts?

[ronnieb]

Well I finally got a TAC module and put it in. I checked for throttle movement with just the key on and only had partcial movement. like quarter throttle. Still had the same code P0122 showing up. I've read that sometimes a sticking thorttle plate may be the culprit so I took it off and so not to damage the throttle motor and TPS i took them off before cleaning. Got the throttle body all shinny and new, put the motor and TPS back on, mounted it , hook up the connectors and now I have nothing, no throttle movement at all. I checked the voltage on pins A and B of the TAC module, supposed to be 5.0v but now I have nothing, 0v. Did I screw up by taking the throttle body appart and fry the new TAC module?

Please somebody help???

[ronnieb]

TAC module appears to be ok. phew..

Does anyone have a part number for the Linear motor on the 02 Tahoe throttle body?