Engine wiring/vacuum connections!

[jgasca]

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.

Well I'm not familiar with an ESC, Electronic Stability Control I'm guessing, but here's a pic of whats under the pass dash;

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I'll be trying another oil pressure switch tomorrow, if that doesn't work, i'm not sure what will

 

[HotRodPC]

That looks like ESC to me. Electronic Spark Control. All it does it retard the timing when a knock is detected from the knock sensor. Very basic computer system with only a knock sensor and a 4 wire plug to the dizzy.

 

[Guardian]

Yes that is an ESC, not an ECM. That would explain the mimssing fuses.

 

[HotRodPC]

Yes that is an ESC, not an ECM. That would explain the mimssing fuses.

And missing ALDL. I am all for keeping emmisions and computers, but that is one I think is OK to let go of. It's so basic and doesn't do a whole lot. However, it can be beneficial again in todays day and age. Some think it's it's a performance enhancement. Not so much. Probably more of an mpg enhancement if anything. If you stop and think back in the 80's this is when fuel octanes were coming down. So you could get 89 octane as the base gas and 91 was as Super, and then still get Leaded Super at 93. So if you're vehicle is tuned to 89 octane, then you buy fuel at a station that was transistioning to 87, this system would retard your timing for the lower octane fuel when it detected a knock or ping. So today, you could actually tune your truck for Super and advance the initial timing, but if you didn't want to get the Super this tank, so be it. Get the 87 and the ESC would compensate for you. The more spark advance you get, the more mpg you can get and some added performance. But, you can take this device out, tune your truck for 87 and be done with it. There is a way and you have to know which wires to twist together, and which to ground, but there is a 4 wire connector on the dizzy that you can convert this dizzy to simple straight up HEI without changing the dizzy. Most people just get a stand alone HEI cheap Pro Comp dizzy off eBay for about $45. Brand New Dizzy with HEI module, coil, coil pick up, cap and rotor. You can't beat it since a cap and rotor alone these days is $25, then add a new module for $30 you're ahead of game and stil have a new dizzy with new bushings, new coil and pickup to boot. On my old trucks, I pretty much try to keep it simple stupid, so I would convert to the standard HEI dizzy and be done. It's not like I'm going to be running 89 or 91 octane in an 8.5 to 1 compression motor anyway. So with all that, that's all ESC does for you. If you want to get around it for simplicity, go for it. I do beleive a temp switch was also used in this set up only to avoid allowing timing advance until the motor was warmed up which reduces NOX (Nitrogen Oxides) emmisions. If not, I am sure the old style vacuum switch in the thermostat housing did the same thing by running the ported vacuum to one side of the vac temp switch, then the other side to the dizzy to block vac advance until the motor warmed up. I'm not totally up on that, but those are the 2 ways of blocking vac advance until motor is warm. Anyone feel free to correct me if wrong, as said, I'm not totally up 100% on that like I used to be and I know model years differed also.

 

[Guardian]

You have it right.

 

[HotRodPC]

Not sure if this any big help here, and it might even be a bit different, but I'd imagine it pretty damn close to right on with an 85 too. This Vacuum routing diagram and timing specs are off of an LE9 305 engine with ESC in 1981.

 

[HotRodPC]

Also if helpful in removing the ESC if you choose too, here is a pic of what it consists of. This is the whole stand alone harness and ESC control box. You see the 4 wire plug for the dizzy. The little sqare block is the connection for the knock sensor on the passenger side of the block, and then a ground lead. I'm pretty certain the system gets it's power from the dizzy thru the 4 prong wire connection, which the dizzy gets it's power from the ignition wire plugged into the dizzy cap. So it's this easy to remove the ESC. No wires are connected to your main chassis harness, so no fear of goofing it up. The ESC is a stand alone harness just as pictured below. Not much to it all. The big round grommet is where the wiring hanress goes thru the firewall just to the right of dizzy. Also the same hole used if you'd have had a TBI harness going thru the firewall, and how you'd route a TBI harness if you were doing an upgrade.

 

[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.)
If the warning light remains lit when it normally should be out, replace the engine unit before proceeding further to determine the cause for a low pressure indication.
The warning light will sometimes light up or flicker when the engine is idling, even though the oil pressure is adequate. However, the light should go out when the engine speed is increased.[/I]


See the highlighted section of this schematic (disregard where it says V6 engine only - it's supposed to read V8 engine only):

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So according to the diagram, there should be a blue and pink/white wire going into the plug on the oil pressure switch.

I'm seeing green, blue and pinkish wires going into the plug.

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Like I said before, when I connected a paper clip into the plug, the choke light (bulb check) worked (engine off ignition turned). I tried grounding one prong or slot of the plug (like the troubleshooting directions said) and it sparked like crazy, I tried the other and nothing happened. I made sure all bulbs were good on the cluster so the bulb wouldn't be the issue.

My other problem is the battery gauge. When i turn the key the needle moves just a bit. According to the diagram a brown wire goes to the alternator from the cluster.

Other than these two problems, I think we're very close

 

[89Suburban]

Does this help?

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[jgasca]

Does this help?

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Could you send me the whole diagram? I'll check it out more when i get home

 

[89Suburban]

Could you send me the whole diagram? I'll check it out more when i get home

I'll shoot you a PM hoss.

 

[Jims86]

In 85-86, they had a 2 port thermostat housing which had a CTS for ccc( a thermal vac switch for the non ccc) trucks, a coolant temp switch for the choke, and the sender for the gauge was in the drivers side head.

 

[HotRodPC]

In 85-86, they had a 2 port thermostat housing which had a CTS for ccc( a thermal vac switch for the non ccc) trucks, a coolant temp switch for the choke, and the sender for the gauge was in the drivers side head.

Isn't that referred to as a VTS in the Tstat housing? Vacuum Temp switch, or is there another temp switch for the ECM so it knows when it can go into closed loop operation???

 

[jgasca]

now all my gauges work except my battery gauge (Which was working before I took it apart. The battery gauge barely moves when the truck is started.

Check the 20 amp fuse in the "gauge/idle" slot, guarantee it's blown. Almost always gets popped when working on the dash.

Well everyone can start sighing + point and laugh..............

I was using a test light that shows continuity to test my fuses. Turns out my gauge fuse was blown but was still showing continuity when it was plugged in......

Well I'm sure i'd get smacked behind the head by a lot of you... but anyways all my gauges work, choke light turned off...all warning lights work..

Thank you all for all your time and effort....post your Paypal so I can send you at least enough for a cold one.

 

[HotRodPC]

Very Cool !!!