Engine wiring/vacuum connections!

[Guardian]

Sorry I'm late getting the diagrams uploaded, work has kept me busy till now. They are in an album at my profile. Hope it helps.

 

[89Suburban]

I finally found something on one of the unplugged connectors.

The green highlighted connectors shown here

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The grey connector is connected to a hot wire then leads to the tan plug which plugs into a 2-stage accelerator pump on the front pass side of the carb

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then from there it goes to a temp switch on the thermostat housing

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the 2-wire plug on the pass side front of the carbis a 2-stage accelerator pump, and it’s controlled totally by temperature and vacuum controls. It basically gives twice the "squirt" when it’s cold to aid in cold engine operation. I believe this was only done on 85-86 models. I may be wrong though.

Nice job!

 

[jgasca]

I bought a new temp switch

http://www.autozone.com/autozone/pa...qkzZ91shz?itemIdentifier=129189_173413_0_5835

and installed it on the thermostat housing, then wired everything up.

Now it seems the truck is getting flooded with gas, could this be due to the the timing?

I'm running out of ideas with the dam choke light. I think Jerry said the choke light must turn on when the ignition is turned (engine off). Well the choke light does not turn on until the engine is running then it stays on. I'm reading good oil pressure and the temp is just a hair above 100.

I remember having problems with the battery gauge, I read somewhere that the choke light also turns on when the alternator gives ass. My battery hasn't died so I'm sure my alternator is working.

any suggestions or ideas would be awesome.

 

[Guardian]

You can use a DVOM to do a prelim check on the charging system. It should read 13.2 - 14.3 with the engine running. If the choke light does not go off after the engine starts the ecm either has codes or has no power, check the fuses first.

 

[jgasca]

You can use a DVOM to do a prelim check on the charging system. It should read 13.2 - 14.3 with the engine running. If the choke light does not go off after the engine starts the ecm either has codes or has no power, check the fuses first.

All Fuses check out.

Would I need one of these to pull the codes?

http://www.summitracing.com/parts/A...ry=Year|1985|Make|GMC|Model|K1500&prefilter=1

This is new territory for me....

 

[Guardian]

That would be the easiest, but there is a way to pull codes by shorting the ALDL and reading the flashes of the Choke light. You can place a jumper between pins A & B of the ALDL. The Choke Light will display a series of flashes for each code present. A long flash is the first number and the short flash is the second, for example one long flash and two short flashes would mean the code is 12.

 

[jgasca]

The oil pressure warning light should go on when the ignition is turned on. If it does not light, disconnect the wire from the engine unit and ground the wire to the frame or cylinder block. Then if the warning light still does not go on with the ignition switch on, replace the bulb.
If the warning light goes on when the wire is grounded to the frame or cylinder block, the engine unit should be checked for being loose or poorly grounded. If the unit is found to be tight and properly grounded, it should be removed and a new one installed. (The presence of sealing compound on the threads of the engine unit will cause a poor ground.)

I took a paper clip and stuck it into the plug that goes to the two prong oil pressure switch, completing the circuit. The choke light and my e-brake lights came on with the ignition turned (engine off). Now that I do recall we did use some white sealing tape on the thread. Could this be the issue or should I replace the switch?

Correct me if I'm wrong but couldn't I buy another switch, and connect it to the plug (without installing the switch) and ground the thread, this should work right?

That would be the easiest, but there is a way to pull codes by shorting the ALDL and reading the flashes of the Choke light. You can place a jumper between pins A & B of the ALDL. The Choke Light will display a series of flashes for each code present. A long flash is the first number and the short flash is the second, for example one long flash and two short flashes would mean the code is 12.

Where exactly is the ALDL? In the dash on the pass side?

 

[Guardian]

The ALDL should be on the driver's sdie.

http://www.extreme-check-engine-light-codes.com/GM OBD1 Decoder.htm

Here is a good visual reference.

 

[jgasca]

The ALDL should be on the driver's sdie.

http://www.extreme-check-engine-light-codes.com/GM OBD1 Decoder.htm

Here is a good visual reference.

I'll check into it when I get home but I have another question;

I saw ECM and ECMB on the fuse block last weekend. Neither slot has a fuse...... I take it they should have fuses right?

 

[Guardian]

If the truck still has the ecm and you are hooking up all the equipment you will have to have power to the ecm. I don't remember the size fuses to requires but I can check when I get home.

 

[jgasca]

If the truck still has the ecm and you are hooking up all the equipment you will have to have power to the ecm. I don't remember the size fuses to requires but I can check when I get home.

The slots say what size of fuse it takes so you dont need to go through the bother....

The ECM would be under the dash on the pass side right? I'll check when i get home from work.

 

[Guardian]

Yes it is behind the glove box, open it and look up and to the left.

 

[jgasca]

Yes it is behind the glove box, open it and look up and to the left.

So I found the ECM. But when I tried to plug the fuses into ECM and ECMB, there was nothing to plug the terminals to. I mean the slots are there for the fuses but when I stick the fuses in the slots, nothing holds them up as if nothing was in the back of the slots.

Also I took off the two prong oil switch and clean the thread, re-installed it and still nothing.

Also I can't find the ALDL anywhere. Should it be mounted somewhere near the steering column?

 

[Guardian]

Yes, it should.

 

[HotRodPC]

For some reason, I'm thinking if he has no fuses in the ECM or ECMB, then he has no ECM or ALDL. Does ESC alone have an ALDL? He may just have an ESC only truck? I don't recall any of my 85's having an ALDL and I have 3 and had 6 85 and up.