Carbureted 1984 S-10 to 1991 S-10 EFI system swap

58533 Views 413 Replies 14 Participants Last post by jimmykicker, Feb 17, 2020

jimmykicker

Discussion Starter · Mar 18, 2013

Hey guys, I am converting my truck to an EFI system. I have had the parts for some time, but I am finally getting around to it. I have apparently missed a part or two. This is from a 1987 truck, and I am missing a part called a cold start module that apparently set inside the truck by the ECM? Doesn't really look like I need it. It's absent from the later models all together.

what is an Air Control Solenoid? I am apparently missing that too? Any pix? Has a black/pink striped wire in the harness coming from c1 pin on the ECM and the other end comes out and connects to a pigtail with a pink/black wires exiting for other IGN powered sources.

Where should I hook the "crank" fuse wire?

Last but not least...I have these two oil pressure switches. One comes with a tan/white wire (fuel pump signal wire) and exits with an orange (12v hot). The other one has three prongs with brown, black and tan wires. I know the three prong is the safety switch and I know where it goes....but where does the one with the two prongs connect?? That is blowing my mind.

Thanks in advance guys

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jimmykicker

Discussion Starter · #2 · Mar 18, 2013

And by the way, I am using an 8062 ECM....so I am guessing that since this didn't use the cold start module it would be just fine for me to leave that pin unhooked? THe other wires are just an orange, a blk/white (ground) a pink/blk (ign) and the blue that goes from the ECM back to a the plug inside the truck that terminates at the Elapsed Timer Module (cold start module). I'm thinking the same about the "air control solenoid" since this has no home on 88 and newer truck that I can probably clip this? Does it have anything to do with the Cold Start Module?

Any ideas on the oil pressure plugs? Posting a pic.

ANy help is appreciated. This is all I really need to get started.

jimmykicker

Discussion Starter · #3 · Mar 18, 2013

2

This is the cold start module. Ignore the pigtail plugged in. I happened to have it...it happened to fit. The colors were all wrong. so image it not being there. Note too this plug is INSIDE the truck with the ECM connectors

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and here are the oil pump associated plugs....where does the two prong one go??

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jimmykicker

Discussion Starter · #4 · Mar 18, 2013

Tips on cleaning the throttle body are appreciated too. Going with new 4.3 injectors. I am also keeping the Edelbrock intake just adding an adapter plate to make it work. I cannot see any reason why it would not work just fine other than having to work around the trans dipstick tube.

jimmykicker

Discussion Starter · #5 · Mar 19, 2013

Nobody has a clue on any of this?? I have a hard time believing that...I know you guys know this stuff....Help me out.

GEARS

· #6 · Mar 19, 2013

When I tore my engine bay apart, I found the 3 pin connector unplugged and sitting there. After research I came to the conclusion it was only for stock oil pressure gauges, which I don't have. I simply cut the wires, tape, and tucked them into the harness if I ever need them later. The 2 pin connector is for the oil pressure switch, which runs the fuel pump when oil pressure is present.

GEARS

· #7 · Mar 19, 2013

The cold start whatever thing is not needed on a 8062. Heck it didn't even make a difference when I unplugged it from the older 7429.. aparently it stops working after a certain period of time after brand spanking new back in 198X

GEARS

· #8 · Mar 19, 2013

The only air control there is besides the butterflies on a tbi is the IAC valve.. which is just a dink that moves in and out of a hole to meter air at idle to control idle speed. Its the 4 pin cylinder shape part beside the TPS on the throttle body

GEARS

· #9 · Mar 19, 2013

And for cleaning the tbi, just buy a gasket kit, and unbolt the entire thing and clean it all with carb cleaner. Works fine for the ones I've worked on. You may find that the truck will run rich, or lean... so deleting the stock non-adjustable Fuel Pressure Regulator and adding an external one may be in the future.

34blazer

· #10 · Mar 19, 2013

A.I.R. diverter valve control is for the smog pump.

are you able to burn your own chips Jimmy?

The_Raven

· #11 · Mar 19, 2013

I've never heard of a cold start module.

Crank wire just simply connects to the start wire, at the column is a good spot to grab the wire. Originally it would have been fed through a 3 amp fuse in the fuse box.

The orange and black/white wires you mention being inside the cab, in a plug should be your ALDL wires, needed for scanning data from the ECM. There is usually a third wire as well, that is part of the ALDL diagnostic connector.

jimmykicker

Discussion Starter · #12 · Mar 19, 2013

34blazer said:
A.I.R. diverter valve control is for the smog pump.

are you able to burn your own chips Jimmy?

I'm using the chip you got for me bro. ACHT

jimmykicker

Discussion Starter · #13 · Mar 19, 2013

The_Raven said:
I've never heard of a cold start module.

Crank wire just simply connects to the start wire, at the column is a good spot to grab the wire. Originally it would have been fed through a 3 amp fuse in the fuse box.

The orange and black/white wires you mention being inside the cab, in a plug should be your ALDL wires, needed for scanning data from the ECM. There is usually a third wire as well, that is part of the ALDL diagnostic connector.

Any idea off the top of your head what color that crank wire might be? Here's the module from 87 ecm. And in that pic I posted of where the cold start module goes, the other one is aldl....Got that all figured out too.

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jimmykicker

Discussion Starter · #14 · Mar 19, 2013

And thanks GEARS for the comments. That's what I was thinking is that since I am using 8062 I don't even need those wires so I can leave that disconnected....along with that other connector at c1.

jimmykicker

Discussion Starter · #15 · Mar 19, 2013

And let's get down to basics here too. What of the emissions stuff do I REALLY need to leave on there? What all should be hooked up to the throttle body? Also, this throttle body from the 4.3? Supposed to have 3 vac ports....it has 2. The 2.8 has 4. The writeup on betterthanyou says it should have 3 and drill the 4th. But this only has two....not like his pix showing three drilling a 4th.

Mad Max

· #16 · Mar 19, 2013

JK, wish I could help out here, my 2.8/3.4s are all carbed.
My '91 still has all of the TBI stuff intact, just zip stripped out of the way.
It would be pretty cool to see a complete multiport system from a 95 Camaro on your rig.
I know that's not much help, but it would totally be different and make some good power too.

The_Raven

· #17 · Mar 19, 2013

That's not a "cold start module."

It turns the fuel pump on for several seconds after the truck shuts off. IIRC, it was heavy duty trucks only, used to combat fuel vaporization after hot shut shut.

Crank wire: ppl-wht is Purple/white stripe.

jimmykicker

Discussion Starter · #18 · Mar 20, 2013 (Edited)

OK...good. Same color on tue inside of the truck. By looking at the bulkhead connector where I started clipping ECM wires loose I noticed there being one there...so I will just fish it back through a grommet I have back around where my existing bulkhead connector is on my 84. I will snatch a quick disconnect. from something and splice it in.

jimmykicker

Discussion Starter · #19 · Mar 20, 2013

The_Raven said:
I've never heard of a cold start module.

Crank wire just simply connects to the start wire, at the column is a good spot to grab the wire. Originally it would have been fed through a 3 amp fuse in the fuse box.

The orange and black/white wires you mention being inside the cab, in a plug should be your ALDL wires, needed for scanning data from the ECM. There is usually a third wire as well, that is part of the ALDL diagnostic connector.

Okay....let me make sure I have this correct before I start going all crazy. There should be a purple and white wire that is for the crank ecm pin....tells it that the engine is turning over right? Could I not just fuse it and connect this wire at the solenoid and be done with it since the truck is an 84 and there isn't a place on the fuse box where it resided before because it was carbureted? Schematics don't show any such fuse. All the lettering on my fuse box is basically gone from age. These old schematics do show a purple wire coming off the starter which appears to go back inside the truck for the neutral/clutch switch.

34blazer

· #20 · Mar 20, 2013

jimmykicker said:
Okay....let me make sure I have this correct before I start going all crazy. There should be a purple and white wire that is for the crank ecm pin....tells it that the engine is turning over right? Could I not just fuse it and connect this wire at the solenoid and be done with it since the truck is an 84 and there isn't a place on the fuse box where it resided before because it was carbureted? Schematics don't show any such fuse. All the lettering on my fuse box is basically gone from age.

yes all it does it tells the ECM when the starter solenoid is engaged. I left mine disconnected, not sure it thats bad, but havent had an issue yet.

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