Just a few wires left...

[Clod_King]

I don't have an electrical diagram for an 86' chev.

That being said, I wanted to know if there were wires going through the firewall that I could hack in too.

I need 12v signal from ignition.

And I have that orange wire. I tried looking at that write up on the Binder Planet forum, and he used it with a relay to go around the oil sender unit. I am keeping my oil sender unit for the time being. Do I still use that long length of orange wire? Or should I just coil it up and save it for later?

And I need to know which terminal to hook up to for the starter signal. Is it on the solenoid? Or on the starter??

I have more questions, but I forget right now.

 

[dyeager535]

Don't hack the harness. The terminals you need are along the top of the fuse panel. Spade connectors will work, but the stock locking connectors are available in most wrecking yards, in most all GM's this vintage.

Still want to fuse them correctly, but that can be done inline, or more cleanly, in an auxillary fuse panel

 

[Clod_King]

So if I unplug the harness from the pickup, I can just plug it in the harness from my burb??

And I kind of already hacked the harness up...


Not too extremely though. I just took it apart, and then labelled wires, and then routed it again, and taped it up. But I did cut the fuel pump power wire, the VSS wire, a purple and white wire that is supposed to be a 12v switched, the tan and black wire, and that orange wire.

Some of those colors are not coming through the firewall from the fuse block... So I figured I'd have to splice them into a different wire/location.

I geuss I should've asked on here first before following a write up for a different truck...

 

[Clod_King]

Okay, I took pictures to see if I am doing anything right. Most likely all wrong, but hopefuly some of it was correct.

This is my first engine swap. I have never pulled an engine before. So bare with me here. There may be a whole lot of stupid Q&A's.

First picture shows that juntion blocl on the top of the firewall. My questions and wire routing is explained on the picture, but I'll go over it here aswell.

That orange wire has no corresponding wire on the stock 86 chevy wire harness. I cannot get that plug out of the socket to wire it in either. The bolt is just spinning. So I have to splice it in somewhere more accessible, ie: engine bay area.

The two other red wires are labbeled in the picture. The thinner wire was spliced into the 86' harness. I picked the wire that went to the same stock location. I figured it would work...
The thicker wire went down to the main lug on the starter solenoid. This was how my '89 was setup, so I repeated it.


The second picture is just a shot of my fuel pump wire. I figured I could splice in an inline fuse, and shoot it straight to the pump.

The third picture is a shot of my starter crank signal. I see two smaller connecting points on my starter. I don't know which one to use... I looked my wiring diagrams, and found some fuzzy ones for the '86 and they only show one wire, and one mounting point.

I don't want to fry anything on start up. And I need the truck running by the 21 of June. Last possible date is safetied and insured by July 1. My best freind moves to Montreal then, and I want to help him move.

Sorry for all the questions. I really did look, and read, but I only ended up with more questions...

 

[dave w]

I think I need a few more details about your engine swap would really help me out. I'm thinking your adding fuel injection to an 86 pickup? I'm thinking your needing some help with the getting the fuel injection wiring added to / modified into the 86 pickup?

There are several ways going about the wiring. If your short on time, then using butt splice connectors will save time. I solder my wires and use heat shrink tubing on my wire splices for a lasting trouble free service life.

From what I can get from your posts so far ... a wire from the "S" terminal on the starter solenoid will tell the ECM the engine is starting. Usually the orange wires going to the ECM are "Battery +" wires, but not always!

I usually get a fuel injected engine running on an engine stand before installing the engine into a vehicle. I start with the ignition switch wires first, "Battery +", "ON", and "START". Usually pink wires with a white stripe "PNK-WHT" need power from the ignition switch in both the "ON" and "START" positions, but not always! Usually black wires with a white stripe "BLK-WHT" are ground (BATTERY NEGATIVE) wires, but not always! Sometimes a tan wire with a white stripe is a ground wire, but ONLY SOMETIMES!


dave w

 

[Clod_King]

That Orange wire is the one that splits off of the oil pressure sender unit, and the fuel pump relay, and heads off to that plug on the firewall.

I followed all the other wires from their corresponding spot in the computer wire harness. And I marked every ground and plug when I removed the harness. And then reinstalled everything the way it was marked. Now I just have a few wires left... Those are the problem wires.

And yes I am putting an 1989 TBI 350, and wire harness into a 1986 GMC 2500 pickup.

I have both trucks sitting side by side. So I can still grab parts if need be.

I thought that tan and white wire was my fuel pump power supply... Is it not?

 

[dave w]

I am putting an 1989 TBI 350, and wire harness into a 1986 GMC 2500 pickup.

I have a wiring diagram for a 1989 C/K Series Pickup.
What my wiring diagram shows.
TAN-WHT is the power wire to fuel pump and the TAN-WHT is also connected to a TAN-WHT wire that is the input to ECM pin B2 (Fuel Pump Input).
TAN-WHT is also has a wired connected to the input on the Hot Fuel Module (PIN A).
TAN-WHT is from an inline 20 AMP fuse. One side of the 20 AMP fuse is PNK-BLK (pink wire with black stripe) which has a wire that is connected to both the fuel pump relay and oil pressure switch.

dave w

 

[dave w]

The Purple wire with a White stripe PPL-WHT is show as the Crank Input ECM pin C9. There is a 5 AMP fuse inline with the PPL-WHT wire and the "S" terminal (Purple wire PPL) on the starter.

dave w

 

[Clod_King]

You f&*#ing rock Dave. I'll be back, but thank you.

 

[Clod_King]

Okay, I hooked everything up. The fuel pump primes the lines, and that's about it.

I cannot see if it will run because my starter will kick in. I bought a remanufactured unit. I have it hook up properly (directly connected to the + side of battery, and the ignition wire hooked up to the "s" terminal). But I don't get a start.

I don't even hear the solenoid. I get nothing. I tried hooking up the ign. wire to the other terminal, and still nothing...

Does the starter ground itself out through it's case?? And if so that would make the engine it's ground. But how does the engine ground itself to the frame??

I see one ground strap coming off the back of the engine. And I thought I remembered taking one off the front of the engine. But I don't have an unhooked ground. They are all connected.

Could the lack of ground wires make a new starter not function at all? The battery is making 11.44 volts. Shouldn't that be enough the make the solenoid engage?

 

[dave w]

Okay, I hooked everything up. The fuel pump primes the lines, and that's about it.

I cannot see if it will run because my starter will kick in. I bought a remanufactured unit. I have it hook up properly (directly connected to the + side of battery, and the ignition wire hooked up to the "s" terminal). But I don't get a start.

I don't even hear the solenoid. I get nothing. I tried hooking up the ign. wire to the other terminal, and still nothing...

Does the starter ground itself out through it's case?? And if so that would make the engine it's ground. But how does the engine ground itself to the frame??

I see one ground strap coming off the back of the engine. And I thought I remembered taking one off the front of the engine. But I don't have an unhooked ground. They are all connected.

Could the lack of ground wires make a new starter not function at all? The battery is making 11.44 volts. Shouldn't that be enough the make the solenoid engage?

I like to work on ONE problem at a time. The way I do things if the vehicle is in my driveway / shop might differ from what other techs would do.

I like to use a 4ga wire from the battery positive terminal to the large post on the starter solenoid.

Ground wires from the battery can go to several places. The starter should ground itself through the block. I like to run a 4ga battery cable from the negative of the battery to place on the block that has a 3/8" x 16 threaded bolt hole (usually on the head near the alternator bracket) or if the engine is metric a 10mm x 1.5 threaded hole. Usually there is a bare "braided" copper grounding cable from the back of the block (passenger side) that is bolted to the firewall. Usually there is a 10ga or 12ga wire from the block to the frame, sometimes there is a pigtail ground wire from the negative battery cable going to the frame and the body.

A fully charged battery is about 12.6 VDC. 11.4 is low, so I would charge the battery. I have a remote starter switch, so I would try to see if the starter will spin / engage with the remote starter switch once the battery is fully charged.

The ECM is programmed to run the fuel pump for about 2 seconds once the ignition switch is in the "ON" / "START" position. The ECM is looking for a signal from the distributor to keep the fuel pump running. It's a good sign that the fuel pump will prime. Once the engine is spinning from the starter, I would check the injectors with a NOID light, and check a spark plug for spark. Once I know for sure I have "FUEL, AIR, SPARK, Sufficient Starter Speed, and Compression" then the real fun of trouble shooting why an engine won't start begins!

dave w

 

[4X4HIGH]

Yes the starter grounds through the case to the block.

The negative battery cable should always be grounded to the engine and then you should have at least one ground strap from the engine to the firewall and there should also be a secondary wire on the negative battery cable that grounds to the core support.

 

[Clod_King]

On the pickup, the ground went from the batttery terminal, to a bolt on the frame.

I cannot quite remember how the suburban was setup, but I am sure it was the same. And it does not look like the cable will reach.

What if I run two 10ga wires from an intake manifold bolt, to that ground cable on the frame? Would that be sufficient?

And would a bad ground not allow the starter to work? I tried jumping it, and still got nothing. No sound from the solenoid, no motor turning. Nothing.

I'll charge the battery tomorrow during the day. Hopefully that's it...

 

[dave w]

What if I run two 10ga wires from an intake manifold bolt, to that ground cable on the frame? Would that be sufficient?

The AMP Capacity of 10ga for chassis wiring is 55 AMPS. Two 10ga wires has an AMP Capacity of 110 AMPS if both ends of the wires are tied together. 4ga battery cable has a chassis wiring AMP Capacity of 135 AMPS. A fresh remanufactured starter draws about 50 - 60 AMPS.

dave w

 

[Clod_King]

Dave, you sir have alot of electrical know-how.

I realized after having a smoke last night, that the negative cable was never hooked to the frame. You guys were right. I'm gonna hook it up correctly tonight, and see what happens.

I'll keep you guys posted.

 

[Clod_King]

Okay. I hook the battery negative cable to the block.

The starter works now. The engine turns over, but it won't start at all.

I have fuel coming out of the injectors, and the #1 cylinder was checked for spark.

I used the half dead battery, and hooked a second battery to it to get the power up. The other battery scored a 12.4v so I figured it would do the job.

The engine sounds like it wants to go, but barely... I don't get it.

Any ideas??

 

[dave w]

Any ideas??

It's the BASICS? There are 5 things needed to get an engine to start ... EFI engine or not EFI engine.

Fuel - Seems OK.
Air - Seems OK.
Spark- Seems OK.
Sufficient Starter Speed - Seems OK.
Compression - ? The spark plug needs to IGNITE the fuel air mixture at about 10 degrees before Top Dead Center of the compression stroke.

If the vehicle was in my shop, here is what I'd do ... I'd make sure that the distributor rotor aligns with the #1 spark plug wire terminal of the distributor cap with cylinder #1 at 10 degrees before Top Dead Center when #1 cylinder is on the COMPRESSION STROKE!.

That's what I would do.

dave w

 

[Clod_King]

How do I know when the #1 cylinder is in the compression stroke??

 

[dave w]

How do I know when the #1 cylinder is in the compression stroke??

There are several ways to go about figuring when #1 is Top Dead Center (TDC) of the the compression stroke.

The way I go about checking for the compression stroke is to remove the #1 spark plug and install my engine compression tester tool into the #1 spark plug hole. (Did I ever mention I have lots and lots of tools?) I then use my remote starter switch to bump the engine until I see some compression on the compression tester. I then look at the timing indicator and bump the engine with the remote starter switch until engine is 10 degrees before TDC.

I'm sure you know this, but the timing mark will be at TDC for the compression stroke and TDC for the exhaust stroke. It's a common error for beginning auto techs to set up the initial engine firing order with the #1 cylinder setup on the exhaust stroke. Usually a beginning auto tech will only make the firing order setup for the TDC on the exhaust stroke error just once!

dave w

 

[Clod_King]

So I couldn't find the compression tester yesterday, and it's raining today. So I cannot check the spark timing...

But I did change the fuel yesterday. It didn't make a lick of difference...

The thing is though, the engine started, and ran off of that dead batery all the time. I never touched the timing during the engine swap. I only removed the distibuter cap to get the oil pressure sender plugged in...