check engine light? HELP!!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

TireSmoke420 · 08-06-2005, 03:01 PM

i recently put a new 350 into my 87. now ever since then when the tranny kicks down to passing gear the check engine light comes on and it seems to have a lot less power and the gas mileage goes way the heck down. does any one have any ideas on this.

**Captkaos** · 08-08-2005, 05:04 PM

Put a jumper (each end of a jim clip) in slot A and B of the ALDL and turn the key on and count the flashes. It will flash 12 like this: flash......flash, flash 3 times then show a code. Find that code and look it up here: http://www.troublecodes.net/GM/86-88_578.shtml or here: http://www.techedge.com.au/vehicle/aldl160/vn_aldl.htm

87 STEPPER · 08-08-2005, 09:03 PM

It sounds like you up set the tranny tv cable adjustment after your engine change go here to see how to check and adjust it.

I assume you still have the 700r4 installed in the truck.

http://www.tciauto.com/instructions/...ble_adjust.htm

TireSmoke420 · 08-10-2005, 11:50 PM

it bring up the code that says its not getting the data from the distributer to the computer.

87 STEPPER · 08-11-2005, 03:22 PM

Thats your EST Eletronic Spark Timing bypass this is a one wire connector with a tan and black stripe wire find that and reconnect it and that should cure the problem.

The EST should be somewhere close to the dist. near the back of the firewall.

Also befor you reconnect it get your timing light out and make shure your base timing is set at what is specified on the under hood lable.

As long as this wire is disconnected the SES light will remain illuninated.

TireSmoke420 · 08-14-2005, 01:46 AM

wire is conected and light isnt always on

SSC's76 · 08-14-2005, 10:01 AM

If memory serves me theres a ground wire attached the the ESC harness. Thats about the only way that item wouldent function unless you damaged the harness durring the engine swap. Doesnt make sence it would come on whne the truck downshifts. Usualy when somthing like that happens in a situation is a vacuum related sensor. What number code did you pull?

08-06-2005, 03:01 PM	#1
TireSmoke420 One of the few GMC'ers Join Date: Jul 2005 Location: Des Moines, Iowa sometimes Butler, PA Posts: 146	check engine light? HELP!!! i recently put a new 350 into my 87. now ever since then when the tranny kicks down to passing gear the check engine light comes on and it seems to have a lot less power and the gas mileage goes way the heck down. does any one have any ideas on this. __________________ 87' Silverado 4x4 "Young, Dumb And Full Of Cum"

08-08-2005, 05:04 PM	#2
Captkaos www.73-87chevytrucks.com Join Date: Dec 1999 Location: Birmingham, AL Posts: 6,935	Put a jumper (each end of a jim clip) in slot A and B of the ALDL and turn the key on and count the flashes. It will flash 12 like this: flash......flash, flash 3 times then show a code. Find that code and look it up here: http://www.troublecodes.net/GM/86-88_578.shtml or here: http://www.techedge.com.au/vehicle/aldl160/vn_aldl.htm __________________ Chris Lucas 1973 Chevy C-10 1978 GMC Jimmy (2WD) - SOLD 1987 R10 twin turbo LS 1991 R3500 SRW CrewCab 1985 K5 diesel swapped project 1989 K5 2WD conversion w/ Vette susp Project Captkaos Customs 73-87chevytrucks.com

08-08-2005, 09:03 PM	#3
87 STEPPER STILL PLAYS WITH TRUX Join Date: Nov 2002 Location: Melbourne, Fla. Posts: 2,764	It sounds like you up set the tranny tv cable adjustment after your engine change go here to see how to check and adjust it. I assume you still have the 700r4 installed in the truck. http://www.tciauto.com/instructions/...ble_adjust.htm __________________ ~~Bruce~~ MY 87 STEPPER MY 99 2D/WD TAHOE

08-10-2005, 11:50 PM	#4
TireSmoke420 One of the few GMC'ers Join Date: Jul 2005 Location: Des Moines, Iowa sometimes Butler, PA Posts: 146	it bring up the code that says its not getting the data from the distributer to the computer. __________________ 87' Silverado 4x4 "Young, Dumb And Full Of Cum"

08-11-2005, 03:22 PM	#5
87 STEPPER STILL PLAYS WITH TRUX Join Date: Nov 2002 Location: Melbourne, Fla. Posts: 2,764	Thats your EST Eletronic Spark Timing bypass this is a one wire connector with a tan and black stripe wire find that and reconnect it and that should cure the problem. The EST should be somewhere close to the dist. near the back of the firewall. Also befor you reconnect it get your timing light out and make shure your base timing is set at what is specified on the under hood lable. As long as this wire is disconnected the SES light will remain illuninated. __________________ ~~Bruce~~ MY 87 STEPPER MY 99 2D/WD TAHOE Last edited by 87 STEPPER; 08-11-2005 at 03:26 PM.

08-14-2005, 01:46 AM	#6
TireSmoke420 One of the few GMC'ers Join Date: Jul 2005 Location: Des Moines, Iowa sometimes Butler, PA Posts: 146	wire is conected and light isnt always on __________________ 87' Silverado 4x4 "Young, Dumb And Full Of Cum"

08-14-2005, 10:01 AM	#7
SSC's76 No No Join Date: Jun 2005 Location: Pueblo Colorado Posts: 1,781	If memory serves me theres a ground wire attached the the ESC harness. Thats about the only way that item wouldent function unless you damaged the harness durring the engine swap. Doesnt make sence it would come on whne the truck downshifts. Usualy when somthing like that happens in a situation is a vacuum related sensor. What number code did you pull? __________________ 1976 Custom Deluxe SWB Med FMB.3/4 Drop. Gen VI 454, Muncie HD 3 speed With Modified OE Hurst Shifter, 3.73 12 bolt, GMPP HO roller cam, Hooker headers, Performer intake with modified Q-jet, Accel distributor. Best 1/4 12.3 @108. Funnest run 19.84 @88 full 1/4 mile burn out. 1997 K1500 ext cab 5.7 stock except muffler



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