87 chevy burb cranks over but won't fire up need help please... - Page 2

truckerr4us · 05-11-2008, 12:14 PM

hello I checked lastnight and this am all are plugged in and seem to be functioning. 12v to and about 12 v through coil. Ohmed wire harness from both thinking bad or failing line or connection but all is normal no breaks no bad connections. Going through it all again this am and still scratching my head.

gmctrucks · 05-11-2008, 01:35 PM

Check fuses with Ohm meter it might look good but it might be bad maybe check wires on ECU that's right by glove box move them around.

Sneakysportsman · 05-11-2008, 06:34 PM

What about a bad brake switch.

In my opinion, I think that the ECM has lost power somehow.
If there is a new dist and ign module and still no spark that leave 2 things, the oil pres switch, or the ECM.

Chevy_Finatic79 · 05-12-2008, 05:38 AM

do you get 12V to the injectors with the key in the on position?

Chevy_Finatic79 · 05-12-2008, 05:52 AM

Iknow this schematic is for 88'-98' trucks but the 87' is almost identical so it should help you out

I had the same problem with no pulse to the injectors and before I figured out the real problem I just ran a 12V jumper wire from the E.G.R's pink with black chaser wire straight to the injectors either the white or red wire will work. do not hook up the jumper to the green or blue wires the are grounds from the ECM. your motor should start right up and if it does you know the ECM is ok.
if you try the jumper wire take care not to touch the wire to the throttle body it will blow a fuse

truckerr4us · 06-23-2008, 07:29 AM

well it was the pick up coil . now starts with no problems now. Thank you all for the advice.

wojeepster · 06-25-2008, 06:10 PM

Sorry I came in so late on this one...You can test the pick up coil with voltmeter set to ac volts. Get a copy of Tracy Martins "How to diagnose and repair automobile electrical systems" It is about $17 on amazon. It is worth its weight in gold. it is an easy read and I understand electrical systems now... I never did before. (it was hit and miss) Glad you got your problem solved.

05-11-2008, 12:14 PM	#11
truckerr4us Junior Member Join Date: May 2008 Location: Tacoma,Wa Posts: 5	problem suburban hello I checked lastnight and this am all are plugged in and seem to be functioning. 12v to and about 12 v through coil. Ohmed wire harness from both thinking bad or failing line or connection but all is normal no breaks no bad connections. Going through it all again this am and still scratching my head.

05-12-2008, 05:38 AM	#14
Chevy_Finatic79 Senior Member Join Date: Mar 2008 Location: Lincoln NE Posts: 388	do you get 12V to the injectors with the key in the on position? __________________ "She's gonna Freak when she see's my wheels" 85' Chevy C-10 Longbox (Rat) TBI 5.7 Liter/THM350 90' Chevy Suburban 4x4 TBI 350 Cu.In./700R4 http://www.truckforum.org/forums/truck-pictures-176.htm

05-12-2008, 05:52 AM	#15
Chevy_Finatic79 Senior Member Join Date: Mar 2008 Location: Lincoln NE Posts: 388	Iknow this schematic is for 88'-98' trucks but the 87' is almost identical so it should help you out I had the same problem with no pulse to the injectors and before I figured out the real problem I just ran a 12V jumper wire from the E.G.R's pink with black chaser wire straight to the injectors either the white or red wire will work. do not hook up the jumper to the green or blue wires the are grounds from the ECM. your motor should start right up and if it does you know the ECM is ok. if you try the jumper wire take care not to touch the wire to the throttle body it will blow a fuse __________________ "She's gonna Freak when she see's my wheels" 85' Chevy C-10 Longbox (Rat) TBI 5.7 Liter/THM350 90' Chevy Suburban 4x4 TBI 350 Cu.In./700R4 http://www.truckforum.org/forums/truck-pictures-176.htm Last edited by Chevy_Finatic79 : 05-12-2008 at 06:04 AM.

06-23-2008, 07:29 AM	#16
truckerr4us Junior Member Join Date: May 2008 Location: Tacoma,Wa Posts: 5	I found out why my truck was not firing ..... well it was the pick up coil . now starts with no problems now. Thank you all for the advice.

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05-11-2008, 01:35 PM	#12
gmctrucks Senior Member Join Date: Nov 2006 Location: Houston,Texas Posts: 811	Check fuses with Ohm meter it might look good but it might be bad maybe check wires on ECU that's right by glove box move them around.

05-11-2008, 06:34 PM	#13
Sneakysportsman Senior Member Join Date: Jun 2007 Posts: 198	What about a bad brake switch. *In my opinion, I think that the ECM has lost power somehow.* *If there is a new dist and ign module and still no spark that leave 2 things, the oil pres switch, or the ECM.*

06-25-2008, 06:10 PM	#17
wojeepster Senior Member Join Date: Nov 2005 Posts: 62	Sorry I came in so late on this one...You can test the pick up coil with voltmeter set to ac volts. Get a copy of Tracy Martins "How to diagnose and repair automobile electrical systems" It is about $17 on amazon. It is worth its weight in gold. it is an easy read and I understand electrical systems now... I never did before. (it was hit and miss) Glad you got your problem solved.

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