"72 GMC Wideside" Quasi Build Thread

[TrucknAndy]

Due to recent unforeseen events I decided to start a build thread. I bought the truck about a year ago as a 2nd vehicle for me to get to and from work, and the wife could have her car to take the kids to and from school, and such. This is my first classic vehicle so this is your noob disclaimer. I know I overpaid for the truck, but it was one of those I had to have it moments us men get. In any case she has never been much to look at, "good from afar, but far from good" she ran well and that was all great...Until recently. And this is how I ended up with a build thread.

I did the brakes (new everything with the exception of the booster, and intermediate brake lines) and some other minor electrical repairs. Recently, I started having an oil pressure issue. Losing pressure even with acceleration...noob mistake # 1. Check all fluids REGULARLY...old motors seem to seep at the seams here and there unless its a fresh rebuild, new motor, and most importantly done properly. Oil change solved the problem PO(s) did nothing proper with this truck. Did everything the cheapest way, and seemingly with the whatever he had laying around.

To save the everyone the pain of continuing to bore you all with an endless story you/we have heard before we will skip to yesterday. Hop in the truck to head to work (fuel guage is broken, but knew I need to get gas on my way to work), pump gas twice (per this old trucks starting procedure), turn ignition to on, push starter button, and fires right up. Pull away, and it seems she isn't accelerating normally (popping noise with a bogging feeling)...made it less than a block, and she dies. Out of gas, as the guage is broken and I have been unable to repair it yet I double check with a length of hose (bone dry). I have the wife pick me up to get some fuel, filled her up a little, no start.

-This happened once when I coasted on fumes into the gas station. Fortunately there was a mechanic in the adjacent pump who added some fuel to the bowls and she fired right up.

I repeated this procedure with no success. Had a coworker tow me home. I am assuming she is flooded out (was able to remove one spark plug and it was wet on the tip and smelled super gassy. My plan was to remove/check all 8 plugs and allow it to dry over night, and leave the air cleaner off. Sadly, the headers don't allow access to all the plugs, and the exhaust is welded to the the headers. All I was able to do was pull one truck, and attempt to crank to check for spark seemed to be a good spark. I know the fuel is getting there as in my attempts to get her to turn over fuel was leaking out the carb body at the rear linkage points. Let it sit overnight all be it with the plugs still in the engine. Still no start...

So, on to the build part, now that Ive bored everyone to death. My wife loathes the truck, but would rather spend the money on getting it to a more dependable state than spend a lot more money on another vehicle. Just seems very counter productive to her/us. The kids will be out of school in a week so I will be able to use her car most everyday, and work on the truck in my free time over the summer.

I know this all sounds backwards and strange going from talking about a seemingly flooded engine, but it seems anything you touch on this truck has had something done improperly to it. As it applies to this situation when inspecting the carb yesterday (Ede 1406 electric choke) I found that the choke plate had been zip tied full open. It did run fine like this, but when trying to diagnose a problem it makes you wonder what else might have been done to this carb, and if letting the sparks dry doesn't get me on the road further diagnosis of the fuel settings may be difficult. So, unless I receive or find a solution to get this girl going again I am planning to by a new 1406 that I know hasn't been tampered with to learn on, and get this girl running right.

This carb is sitting on top of what I believe is a late 70's 350. Having run the numbers I know its a harder nickel block, with a 4 bolt. I was told it has a mild cam (po) type (unknown). It is fired by an old delco remy HEI.

I have already purchased an AAW classic update (all the wiring is botched, and the fuse block looks like a grave site). So, this will be going in this summer, and if it is seemed a smart move to start with a fresh carb, and a quality ignition system, wires, and plugs. If money allows after the previous I want to end up with an exhaust system that either A) allows access to the plugs while installed, or B) Can be removed without dropping the exhaust.

Sorry for the long winded thread, and I know the first portion could have been posted in the engine section, but it all sort of lead into a long term build, and hoped to have everything centrally located in one place as I plug along on the truck.

I am hoping for some advice how to solve the present problem(s), and/or on my plans for summer upgrades. I'll post a pic of the PO's handy work on the choke later.

Some pics.

Thanks,
Andy





The mess under the hood.

[TrucknAndy]

Update: She lives!! I was bouncing around the site looking at posts about flooded engines. WOT while cranking did the trick. Drove fine at higher RPMs but wont idle on her own. At speed she didn't feel like she had a misfire. I don't think I am competent enough with carbs to rebuild it myself, but getting this one rebuilt or a new carb may solve some of the problem(s).

[mjensen]

Looks like a great truck. I love me some GMC

Have you checked things like the choke mechanism or other items like that? Carbs, while complex, if you take your time and pay attention when you are disassembling are actually quite simple. Tuning them...well that might be another story

[TrucknAndy]

Thanks MJensen! The 1406 is equipped with an electric choke, but as I said the (PO) zip tied it wide open. and the only wire hooked to it is grounded to the carb body. So, aside from the fact its zipped open it needs a 12v ignition on power source. My guess is the PO didn't know that the auto choke was adjustable and couldn't figure it out, or its broken which might explain why its zipped open and no power supplied.

Andy

[mjensen]

Okay, I may have missed it but did you say it did idle before?

[TrucknAndy]

Prior to yesterday it was my DD, and it idle pretty smooth.

[mjensen]

Throws all my theories out Mine was flooding because the floats were stuck in the down position from sitting for so long, causing the bowls to overfill and spill over into the engine. How about fuel pump? Is it running the old mechanical, or is there an electric on it?

[TrucknAndy]

Well the original flooding issue was my doing after running her out of fuel I decided it was a good idea to flood her. Now that she is up and running again she is idling rough.

Andy

[mjensen]

Have you tried to adjust the idle mixture screws at all? And how 'bout that pump, is it electric or the old manual.

[TrucknAndy]

Its a manual pump and I have yet to make any adjustments. Doing some reading on edelbrocks before I start fiddling.

[mjensen]

I would definitely read up on trying to set it to a baseline (or default) to see if you can get it to idle. It would be awesome if it would just take an adjustment to fix your issue.

[mjensen]

BTW, I'm no pro either but I do love to help

[TrucknAndy]

You bet...Ill keep you posted. Less on the carb is more else where. Thanks for your interest and inputs.

Andy

[TrucknAndy]

Well, I ended up not messing with my idle mixture, as I had no way to measure engine speed, fuel pressure, or vacuum. However, this is fine as I have parked the old girl for the summer. I know it sounds completely backwards, but with the kids out of school soon I can use the old ladies' wheels to get to and from work.

Yesterday I took out the bench seat, pulled up the carpeting, removed the POS radio/speakers, and the glove box. Weird to see her like this...its a bit nerve racking.

Step One: Install This!



To clean up this! Disclaimer: I did not foil wrap these fuses...very glad I have the opportunity to remedy this before something bad happens.



and this!



This side of the dash isn't so painful to look at with exception to the radio opening that was destroyed by the PO to install a double din radio/cd/cassette. They used a thin poorly cut sheet of metal to attach the radio to the dash. Eventually I hope to get a new dash or have a patch worked in, but in the mean time I will likely have to mount a new radio in a similar fashion as the PO. Minus the hacking up of a dash.

The Carnage:



Here is the floor pan...that glue should be fun to get up. Surprisingly, there were no surprises under the carpet. I knew the red patch was there...I guess she had a manual tranny in her previous life. Not the end of the world, and I may use it to mount an auto tranny floor shifter from Lokar. If I get lucky and the holes line up. Hole in the floor pan isn't nearly as big as that patch. The only rust hole (Ill post a pic of it later) could be seen even with the carpet down. It is at the seam of the pass side rocker and floor pan. Should be an easy fix down the road.





Is this the ballast resistor used on the older ignition systems?



Lastly, where does this wire connect to? Its part of the A/C harness...the purple wire is connected to the blower, and I am good to go on the vacuum lines I need, as well as having a/c hoses run to the compressor, but I have no clue what this wire is for.





Well, that's it for now. I will keep this as updated as possible as things move along.

[TrucknAndy]

ttt

[TrucknAndy]

ttt

[mjensen]

I have an AC truck in my driveway. I'll check tomorrow and see if I have a wire like that and I'll let you know.

[TrucknAndy]

Thanks Jensen!

Andy

[mjensen]

Andy,
That wire is hooked up to the AC compressor:

In the loom much like yours:


Green wire, kinda hard to follow:


Connector on the compressor


Hope that helps.
Mike

[TrucknAndy]

That looks to be a 2 wire connection at the compressor. Is the green hot, and a black ground in that plug?

Anyways, making some progress on the wiring. I tore all the wiring out of the cab except the a/c harness out of the truck yesterday, cut the fire wall to accommodate the larger bulkhead connecter for the new kit, and got it mounted to the firewall this morning. I have made the first few connections, but I am taking my time to make sure it all goes smoothly.

:: pics coming soon ::

On a side note: Cutting the fire wall and mounting a new fuse box on the fire wall is not something I hope to have to do again soon. Complete PITA!!

-Andy

[mjensen]

Originally Posted by TrucknAndy

That looks to be a 2 wire connection at the compressor. Is the green hot, and a black ground in that plug?

Anyways, making some progress on the wiring. I tore all the wiring out of the cab except the a/c harness out of the truck yesterday, cut the fire wall to accommodate the larger bulkhead connecter for the new kit, and got it mounted to the firewall this morning. I have made the first few connections, but I am taking my time to make sure it all goes smoothly.

:: pics coming soon ::

On a side note: Cutting the fire wall and mounting a new fuse box on the fire wall is not something I hope to have to do again soon. Complete PITA!!

-Andy

Yes, there is a ground wire coming off the connector right to the mount that holds the compressor on.

[Tinkermc]

thrsr trucks are truly a PIA for awhile, there is a lot of help here and soon it will be a decent dailey driver that you can depend on to bring you home

[TrucknAndy]

Picking up where I left off with some photos. First is the cab stripped of all wiring.







Fire wall opening re-sized.



Things starting to come back together...







Got stumped on my wiper motor though. Only 4 tabs on wiper motor.



Both new and old harnesses have 2 double connectors. Below are 2 connectors from the new harness I am trying to install. I believe newer motors have four tabs, but if I don't figure out Ill have to contact AAW next week.







Andy

[mjensen]

Ok, can't help with that one

[TrucknAndy]

I think I am missing the washer pump...looks as though one of the connectors goes to the pump one to the motor, and a single connecter of some other purpose...

Andy