Need 5.7 L TBI engine help - PLEASE - Tried everything - Page 2

crabtruck · 10-24-2009, 04:07 PM

Shhh, don't think bad ECM until no other choice.

Pull codes after timing set and write them down.
Then clear and see which return after ECM relearns a little.

gmctrucks · 10-24-2009, 04:15 PM

Quote:

Originally Posted by Chevy_Finatic79

did you adjust the valves while the motor was running or just when you replaced the lifters not running? if the valves are too tight and never close it will run like **** and burn the valves also are you sure one of the cam lobes arent flattend out?

This is a super good question that Finatic70 asked. Also crab always knows what he's talking about. The wiring I was talking about is to set the timing on zero.
Good luck! GMC

hippiegroove · 10-24-2009, 04:35 PM

Quote:

Originally Posted by Chevy_Finatic79

did you adjust the valves while the motor was running or just when you replaced the lifters not running? if the valves are too tight and never close it will run like **** and burn the valves also are you sure one of the cam lobes arent flattend out?

I adjusted the rocker arms according to how the book says to do it on that particular vehicle - and its pretty much like any GMC / chevy 350..
adjustment made till no more clacking , then turn 1/4 turn back..
This was one of the first things i tried after i got the van thinking that instead of the lifters being collapsed it may have been that.
After replacing the lifters - i tightened them down non running - then started Van up and made adjustments accordingly..

hippiegroove · 10-24-2009, 04:47 PM

Ok. So i found the wire for the timing - its tan with a black stripe and its connected to the harness that goes to the distributer , but is by itself.
I put the vacume lines back to the egr off the egr solonoid , and the vaccume off the map sensor. disconnected the battery. Took it for a drive - first time round the block - little sluggish - but seems to shift alot smoother now. 2nd attempt - pulled timing plug - started van and played with the dist timing again while in park. Took it for a drive and it seems to be alot smoother now - but still not running like it should..Check engine light comes on after it runs for a min or so - but no codes other than the test code from start to finish.
So that timing wire def had some factor in this problem and now it runs and drives like it did while vaccume hoses were disconnected - but runs a bit smoother now.

Any other suggestions ?
I was reading in the Chiltons that the knock sensor could make the vehicle run like this perhaps - anyone know about that ?
only other thing im thinking could be the ESC module
Both seem to work together when it comes to emissions , fuel , and the computer

I found someone selling all the sensors on e-bay for 40.00 --- Wish i came across this before i spent 100's on everything - and it includes the esc mod which i think i may possibly need

Also found a TBI that came off a running Chevy with a bad motor for like 60.00 shipped - Could the TBI perhaps be an issue ? I replaced the fuel regulator and cleaned out the injectors , and ran an additive as well..

scavanger · 10-24-2009, 04:58 PM

I didn't see any mention of replacing the plugs. With all the parts you bought I would guess that you did. I discovered on my 95 that plug gap does effect the way they run significantly.

Scav.

hippiegroove · 10-24-2009, 06:13 PM

Quote:

Originally Posted by scavanger

I didn't see any mention of replacing the plugs. With all the parts you bought I would guess that you did. I discovered on my 95 that plug gap does effect the way they run significantly.

Scav.

Actually i didnt replace the plugs , but i did pull them out and looked them over. The gal i bought the Van from had me talk to her mechanic , and he told me all he had done to it and plugs , wires , cap and rotor were all mentioned along with Map Sensor and EGR valve - he also was the one that said it had a collapsed lifter

I didnt however check the gap to amke sure it was accurate.. I will feel so daym stupid if thats what it is.

crabtruck · 10-24-2009, 06:56 PM

Shhh, don't think bad mech until no other choice.

Pull plugs after timing set and hide them.
Then blame orig mech and say wrong plugs after mech relearns a little

hippiegroove · 10-24-2009, 09:53 PM

Well , i drove it more today , and i wound up having to plug the Map sensor Vaccume line again to make it get up and go.
It seems like the more i do to it it runs better for a min , then gets worst.

With no job , and lack of $ - its a bit hard to buy the parts i " think " it may be.
This van has been a total nightmare since i bought it and has cost me a small fortune.
I will have an almost new van when its finally figured out..

Chevy_Finatic79 · 10-25-2009, 01:51 PM

to test your knock sensor "you'll need a helper" hook a up a timing light watch the mark on the dampener while the helper taps the motor with a hammer no make sure they dont tap to hard but if the knock sensor is working you'll see the timimng mark move as the helper taps the motor if it doest move the knock sensor isnt working

jbarker · 10-25-2009, 03:27 PM

I just went thru just about the same drill you are in the midst of, except with my 94 K2500 350. I rebuilt the entire engine. The EGR ports in the manifold were plugged solid - you might want to check this; other posts in this forum report the same finding. Unbolt the valve and take a look. Also my temp sensor was bad - ohmed at infinity. This is the two-wire one by the thermostat. Finally, I sandblasted both my plug electrodes AND the end electrode where the wire hooks on. This took me from no-start to smooth run. And I'm telling you, those plugs weren't in bad shape and I had wirebrushed and gapped them before. You'll find this same story elsewhere on this forum as I complete the loop on one of my posts. I feel your pain.

10-25-2009, 01:51 PM	#19
Chevy_Finatic79 Senior Member Join Date: Mar 2008 Location: Lincoln NE Posts: 478	to test your knock sensor "you'll need a helper" hook a up a timing light watch the mark on the dampener while the helper taps the motor with a hammer no make sure they dont tap to hard but if the knock sensor is working you'll see the timimng mark move as the helper taps the motor if it doest move the knock sensor isnt working __________________ "She's gonna Freak when she see's my wheels" 85' Chevy C-10 Longbox (Rat) TBI 327 Cu.In./THM350 90' Chevy Suburban 4x4 TBI 350 Cu.In./700R4 http://www.truckforum.org/forums/truck-pictures-176.htm

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10-24-2009, 04:07 PM	#11
crabtruck Senior Member Join Date: Jul 2007 Location: on your 9 Posts: 3,364	Shhh, don't think bad ECM until no other choice. Pull codes after timing set and write them down. Then clear and see which return after ECM relearns a little.

10-24-2009, 04:47 PM	#14
hippiegroove Junior Member Join Date: Oct 2009 Posts: 11	Ok. So i found the wire for the timing - its tan with a black stripe and its connected to the harness that goes to the distributer , but is by itself. I put the vacume lines back to the egr off the egr solonoid , and the vaccume off the map sensor. disconnected the battery. Took it for a drive - first time round the block - little sluggish - but seems to shift alot smoother now. 2nd attempt - pulled timing plug - started van and played with the dist timing again while in park. Took it for a drive and it seems to be alot smoother now - but still not running like it should..Check engine light comes on after it runs for a min or so - but no codes other than the test code from start to finish. So that timing wire def had some factor in this problem and now it runs and drives like it did while vaccume hoses were disconnected - but runs a bit smoother now. Any other suggestions ? I was reading in the Chiltons that the knock sensor could make the vehicle run like this perhaps - anyone know about that ? only other thing im thinking could be the ESC module Both seem to work together when it comes to emissions , fuel , and the computer I found someone selling all the sensors on e-bay for 40.00 --- Wish i came across this before i spent 100's on everything - and it includes the esc mod which i think i may possibly need Also found a TBI that came off a running Chevy with a bad motor for like 60.00 shipped - Could the TBI perhaps be an issue ? I replaced the fuel regulator and cleaned out the injectors , and ran an additive as well..

10-24-2009, 04:58 PM	#15
scavanger Senior Member Join Date: May 2007 Posts: 262	I didn't see any mention of replacing the plugs. With all the parts you bought I would guess that you did. I discovered on my 95 that plug gap does effect the way they run significantly. Scav.

10-24-2009, 06:56 PM	#17
crabtruck Senior Member Join Date: Jul 2007 Location: on your 9 Posts: 3,364	Shhh, don't think bad mech until no other choice. Pull plugs after timing set and hide them. Then blame orig mech and say wrong plugs after mech relearns a little

10-24-2009, 09:53 PM	#18
hippiegroove Junior Member Join Date: Oct 2009 Posts: 11	Well , i drove it more today , and i wound up having to plug the Map sensor Vaccume line again to make it get up and go. It seems like the more i do to it it runs better for a min , then gets worst. With no job , and lack of $ - its a bit hard to buy the parts i " think " it may be. This van has been a total nightmare since i bought it and has cost me a small fortune. I will have an almost new van when its finally figured out..

10-25-2009, 03:27 PM	#20
jbarker Full Member Join Date: Sep 2009 Location: New Hampshire Posts: 31	I just went thru just about the same drill you are in the midst of, except with my 94 K2500 350. I rebuilt the entire engine. The EGR ports in the manifold were plugged solid - you might want to check this; other posts in this forum report the same finding. Unbolt the valve and take a look. Also my temp sensor was bad - ohmed at infinity. This is the two-wire one by the thermostat. Finally, I sandblasted both my plug electrodes AND the end electrode where the wire hooks on. This took me from no-start to smooth run. And I'm telling you, those plugs weren't in bad shape and I had wirebrushed and gapped them before. You'll find this same story elsewhere on this forum as I complete the loop on one of my posts. I feel your pain.