87 1500 Not Getting Power to TBI Injectors

[87 grey ghost]

Hey guys probably a stupid question!
But looking at the diagram above for the
ecm circuits which way should I be holding
The plug in my hand to cordinate with the diagram?
If I'm holding the plug and have the clip of the
plug on the left side and the #1 at the bottom then the left side
of the plug would be either A or C ? Thanks

 

[87 grey ghost]

Sorry guys it was a dumb question I had it
backwards.

 

[Jims86]

Hey guys probably a stupid question!
But looking at the diagram above for the
ecm circuits which way should I be holding
The plug in my hand to cordinate with the diagram?
If I'm holding the plug and have the clip of the
plug on the left side and the #1 at the bottom then the left side
of the plug would be either A or C ? Thanks

The cavities are numbered on the plugs from the side where the wires come in.

 

[87 grey ghost]

Hi Guys, Ended up testing a few circuits and found no
power in any way at the B1 and the C16 circuits going into the ecm
so I ran a hot wire with an inline fuse to both and it fired right up.
Now I'm gonna see y it won't go into 4x4
Thanks for everything

 

[HotRodPC]

So you're on the right track. Now you need to figure out where and how and why the OEM power isn't getting there.

 

[Jims86]

So you're on the right track. Now you need to figure out where and how and why the OEM power isn't getting there.

Those wires go to the ECM B fuse, he has an electrician typ dude that is going to see if there is a break in the wire(s) somewhere. maybe a bad connection at the firewall plug cavity.

 

[MrMarty51]

 

[87 grey ghost]

Yes finally on the right track.
Next dilemma is that the 4 wheel drive lever
won't move so I'm gonna see if the linkage is
frozen or worse.

 

[89Suburban]

Those wires go to the ECM B fuse, he has an electrician typ dude that is going to see if there is a break in the wire(s) somewhere. maybe a bad connection at the firewall plug cavity.

Let us know how this goes. Good job keeping at it and figuring it out everyone.


Posted From Hell

 

[87 grey ghost]

HI Guys,
just double checking some info to make sure its correct!
My transfer case tag says 208 c 1 so making sure its an 27 spline input which
would bolt up to an th350 or a 700 r4 tranny? thanks

 

[HotRodPC]

HI Guys,
just double checking some info to make sure its correct!
My transfer case tag says 208 c 1 so making sure its an 27 spline input which
would bolt up to an th350 or a 700 r4 tranny? thanks

NP208 comes in different varieties. Most common is the 27 spline for GM, but is also found in 32 spline for Th400, SM465 and A833 manual transmissions.

 

[87 grey ghost]

Ok guys here's where I'm at now!!
Bin driving the truck around some, Blew a
spark plug out!! Then while replacing the rest
one stripped off. So another project!!
Also got the 4 wheel drive to work but the lever keeps
slipping forward. And haven't got to the leaking
transfer case yet. Well ill keep pluging away
and keep you all updated.

 

[gxrardo]

Hello I hope everyone is doing well. I was following this forum I have an 87 R10 TBI and I'm having a no pulse problem. Changed ICM, distributor, and ECM. Checked with noid light and no pulse and also no power. I checked my wiring and I have 12v to B1 and C16 but no power to A6 what do I do from there? Fuse shows connectivity but I'll throw a new one just in case.

 

[gmbellew]

Looks like A6 comes from ECM I fuse to ECM. It should only be 12v with key ON. If the fuse pops on key ON. You have a short to ground. I had an issue one time where ECM I was shorted to ground on a wire running to the TCC solenoid. Sometimes odd things are powered in odd places....