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EZ EFI 2.0 Throttle Body System Vehicle #2 - An '81 GMC

Discussion in 'FAST Support Forum' started by A A, Jun 5, 2016.

  1. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Set idle A/F to 14.3 and saw a very slight improvement in cold start and warm idle vacuum. Changed cranking enrichment to -4, but saw no real change in warm start - which remains excellent. Set accel fuel to -2 and removed a very slight warm engine stumble just off idle on acceleration. ECU settings feel very close now.
     
    Last edited: Feb 20, 2018
  2. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Current numbers that have this 355 Chevy engine running very sweet:

    Timing:
    20 degrees initial
    26 degrees mechanical @4000 slope
    12 degrees vacuum advance @40%
    2 degrees idle trim

    A/F:
    idle 14.3
    cruise 14.7
    WOT 12.6

    Enrichment:
    accel fuel -2
    cranking fuel -4
    cold start -8

    Current Fuel:
    Chevron 89 octane
     
    crash520 likes this.
  3. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Lol. a while back I installed a Scytec Galaxy remote starter to my '81 GMC. I've hardly ever started the truck with it, mostly just unlocking and locking the doors with it - but, it works perfectly. Today, I saw, from inside a window on my home, one of my cats was sound asleep on the hood. I usually just open a house door and holler at them to get down when I see this. Today, I pressed the remote start button, the cat sleepily looked around as fuel pump came on - then the engine started. The cat must have jumped two feet into the air getting away - like it had been electrified! Don't know why it took me so long to think of using the remote start as a deterrent to the cats getting on my vehicles - sure worked good today. I guess I really should start using all the security features - probably wouldn't have had my gas stolen a while back if the system had been armed, and using a proximity feature.
     
  4. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    I've had a BatteryMiINDER OBD-12 installed to my GMC for several years. I kept it plugged into a solar array using a 10amp solar supply. It has worked great and the SLA battery in the GMC is still like brand new at 100% capacity. After installing a 10amp NOCO GEN 1 in my new Silverado, I decided the 4amp GEN 1 Mini would be a better choice for the GMC than the BatteryMINDER. The NOCO GEN 1 and GEN 1 Mini are certainly more rugged (rated IP68 water resistant), and they cycle off to micro power and sensing when the battery is fully charged - should be good for even longer battery life along with their eight stage charging and power cycling. The new system appears to be working fine and it is supposed to be completely computer safe - for my EZ EFI 2.0 ECU peace of mind. The solar array still does all the charging - only from one of its 120 volt AC outlets.
     
  5. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Lol! For the last two weeks I had noticed my FAST handheld was showing 13.9 volts instead of the usual 14.3 volts after starting my GMC. After a while driving, volts would only come up to 14.1 - and drop back slightly at anything over idle speeds. Yes, the now 14 year old Powermaster 150 amp alternator was acting up. Seems like it all started with the oppressive humidity we're having at the current time.

    I pulled the GMC battery and checked it out - although it still cranked the truck perfectly. Its capacity was low, but I built that back quickly using a NOCO Genius G7200 7 amp charger. I installed a weak Duracell AGM battery to the GMC that was showing 12.8 volts. Ha! It couldn't turn the engine over as its capacity was gone and the volts fell off far enough to cause a reboot of the handheld, as I let off the start position of the key and volts increased - but I used a new GB70 booster to easily start the engine. Yup, with the engine then idling, booster disconnected, the handheld volts quickly increased to 13.9 - but there was something odd. My warm engine idle was drifting between 800-900 rpm instead of holding at 750.

    I bought a new Duracell 34/78 AGM I found on sale for the GMC, as the old AGM had lasted 8 years before I replaced it in one of my other vehicles that is driven more often. I also like the top and side terminal configuration of this AGM. I used the old AGM for the $18 core charge and my total cost for the new AGM was only $121 at Sam's Club.

    The battery that had been in the GMC was still in great condition, but it is 6 years old - I'll use it for something else. So, I installed the new AGC into the '81 GMC. A quick check showed my old Powermaster alternator was discharging the battery at a low amperage with the key off. So, I left the negative terminal disconnected. The old GMC will soon have a new alternator - but the above told story serves to show yet more quirks, how they can be spotted with the EZ EFI 2.0 handheld, and how they can affect the ECU operation.

    Edit - It's probably a good thing the GMCs NOCO mini charger had been in use or the old GMC battery would have probably been toast from the alternator discharge.
     
    Last edited: Jun 2, 2018
  6. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Time to play with this thread again. I can't tell, but my doctors say my cholesterol and blood pressure is now good after over twenty years of telling me the opposite. At least I never get colds. Blood sugar, ahem.

    But, my GMC runs like a healthy grizzly. I haven't been driving it much, but did recently. I traded my 20 year old Kubota Grand L 3010HST loader in on a new Kubota Grand L 4060HSTC loader. The new air conditioned tractor cab makes the heat outside a non issue and I am comfortable running the new tractor. It does burn more fuel than the smaller 3010 did. Needing diesel fuel was the occasion to fire up the GMC. I loaded a fuel tank and drove the GMC to pick up 100 gallons of diesel fuel. If the fuel weight hadn't dropped the bed height a few inches, I wouldn't have noticed anything. The engine sure never appeared to be under any strain at all.

    Apparently, the last fuel injection settings and timing changes I made to the GMC were perfect. While I haven't actually checked the mileage, I'm sure that improved considerably from the 12.5 mpg I had before those changes. With the fuel tank unloaded, I drove the GMC again today. Man, it really wants to light the tires up with ease. Almost every time I took off from a stop, I barked the tires for more than a few feet. I didn't think I was giving it that much throttle. I just hope I'm not getting too old to properly handle the quick power response it has. Maybe it was just the old hot rodder subconsciously resurfacing in me - I hope.
     
  7. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    I hadn't liked the factory rear speaker housings in the GMC as they are complete garbage. They certainly didn't compliment the Infinity Kappa 6x9 rear speakers I bought last year - powered by an eXcelon XR400-4 amplifier. So, I purchased a sheet of 3/4" chipboard and built a custom sealed speaker enclosure to fit below the back window and hidden by the seating.

    I had intended to re-wire the amplifier today and enjoy the much improved sound stage offered by the sealed enclosure. As luck would have it, it is raining now and I'm unable to work on it. I have two new choices for mounting my FAST E6 ignition box that formerly sat where one side of the new speaker enclosure sits.

    One position is where the factory had the driver side rear speaker. The other is below the eXcelon amplifier in an opening I designed in the center of the speaker enclosure. (It has two sealed enclosures either side of the 12" wide open center cabinet.) Mounted in the center below the eXcelon amplifier, I have to wonder if there will be any electrical interference. If I use the old factory speaker position for the E6, I may just customize the E6 ignition box to be recessed somewhat. In that position, I know there will be no electrical interference, but the E6 will not be hidden. It's a toss up I'll have to decide on.
     
  8. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    I wired the rear speakers up today - as luck would have it, one side of one of my RCA patch cords from the stereo to the amplifier was bad. Installed a new patch cord. The rear Infinity speakers now sound great - also providing something of a massage through the seatback. Bass is much deeper with zero unwanted body vibrations coming from the factory rear corner speaker areas.

    I temporarily installed the FAST E6 ignition box directly below the Kenwood XR400-4 amplifier and ran the engine. There were no electrical interference surprises from any direction. So, the FAST E6 has found its home centered under the Kenwood amplifier. As for the factory speaker positions, they will become lockable, insulated, and sealed storage areas. All that is left is minor audio adjustments to the Kenwood eXcelon KDC X998 headunit using one of my favorite oldies albums - like the Raiders Collage album Mark Lindsay worked so hard at mastering with analog equipment.:D
     
  9. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Wow! It sounds like I have a slight reverb effect with the volume turned up. Slightly over half volume drowns out everything with the windows up without being obtuse or overly loud - and I still have some small areas of the cab to insulate.
     
    Last edited: Nov 4, 2018
  10. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Popped for new door panels and a headliner for the GMC today. I was at odds on LMC Pro Classic Sport seats or just getting late model electric leather seats. With more rough measurements, it looks like I have to go with the LMC seats - but I did find a really nice set of 2017 factory leather power seats with the center console/seat. the '81 GMC bench is roughly 56 inches wide and the late model seats overall at about 60 inches. There was also a height difference that would have required changes to the '81 floor pan, and probably shifting or removal of the factory side tanks. So, LMC Pro Classic Sport seats it will be.
     
    Last edited: Nov 8, 2018
  11. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    I already had a new OEM brand vinyl dash pad from Classic Industries - pure garbage I'll be tossing. It had deformed after only a month in the summer sun. I bought the fiberglass backed LMC Pro Classic Sport dash pad and the split bench Pro Classic Sport seat and bracket this afternoon. The Pro Classic Sport split bench seat is 60 inches wide, but the seat area isn't as high from the floorboard as factory '17 model seats - even using the required LMC adapter bracket. The GMC interior will soon be all brand new and my pockets about three grand lighter. Should be here next week.
     
    Last edited: Nov 8, 2018
  12. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    After installing the new rear speaker box, while waiting for the new interior, I've noticed some slight strangeness with my EZ EFI2.0 F/A in the GMC. I've been running only mid grade fuel instead of regular for a number of months now. A plug check showed some light ceramic sooting, but still looking good. The engine was running slightly rougher at cold start until it warmed, and I noticed exhaust was no longer looking as clean as it had in warm engine WOT acceleration. I had also begun getting sporadic 003 IRM readings.

    I changed WOT from 12.6 to 12.5 and the exhaust during WOT acceleration immediately cleaned back up. Since the cold start appeared rich, I took the idle F/A to 14.5 - leaving the enrichment setting where it was. Cold start has now settled to a smoother idle again. I also changed cruise F/A to 14.8 and accel fuel enrichment to "0". Timing and heat range still looks correct at the plugs, and the plug ceramics have only returned to a clean white coloration. The IRMs have gone back to the 000 readings I had grown accustomed to. I'm hoping this strangeness isn't signaling the O2 sensor going bad. Maybe there was just some carbon buildup somewhere in the old engine that is going away.
     
  13. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Seating and dash parts for this GMC are arriving tomorrow. Naturally, the weather here is miserable constant rain and expected to remain so throughout next week. As a result, I haven't been able to get the truck ready for a quick install of the new interior. Of course, the carpet and sound deadener supplies are also shipping last - just my luck. At least the truck is running sweet on the new settings.
     
  14. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Lol. As usual the weather forecasts were dead wrong - it snowed this morning. It was biting cold, but I took delivery of the dash, seat, and seat bracket. I'm hoping the rest of the LMC parts will still come FedEx tomorrow. I have the GMC in my heated garage, so I will install the dash today - along with a new heater core. Of course, when I drove the TA out of the garage last night, I put the car cover on front to rear in the dark. So, I still get to play in the cold as I turn the cover around.

    Edit: Of course, after I assembled the seat and left it sitting in the truck bed, life had to take a twist. As I began getting ready to install the new dash, I found they sent a red stitched dash instead of white. Now I have to wait for the correct dash.
     
    Last edited: Nov 15, 2018
  15. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Installed the glove box today and took out the old rotten headliner. Don't know how that headliner was looking as well as it did. I'll give GM the bird on their '81 truck glove box latch design - It was a PITA to get apart without damaging anything. I decided to repaint the interior metal after the cleanup. But, I'm undecided on black or royal blue. The royal blue will probably give some needed contrast with the black interior - although the white stitching already helps. Should have the new headliner installed in the next few days - then, on to installing new the carpet and seat. The weight of the new seat has surprised me - it's heavier than the old one. I'll also be replacing the rest of the plastic trim parts. They're just too brittle - even though they still look new.
     
  16. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Got my interior paint yesterday, but I've been running my Kubota loader filling in and leveling a steep area in my orchard while the rain is holding off. Planted a few new fruit trees as well - and was promptly visited tonight by four deer. Good I also put wire fencing around the trees.

    I've been told the replacement white stitched dash should come next week. I have the truck inside my heated garage now, so there's no real hurry other than I'm not getting to enjoy driving it.:(

    The new door panels look great, but I've got to do some creative metal work to fit the Infinity door speakers high in the panels. I don't want them low where they can be hit by shoes getting in and out of the truck. I'm also thinking the small Infinity tweeters might look and work better in the rear pillar moldings.
     
    Last edited: Nov 21, 2018
  17. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    As Al Jolson would say,"Hot diggity dawg!". My correct dash is arriving tomorrow!
     
  18. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    The new white stitch TMI dash from LMC and new dash trim looks great! I still need to weld in some new custom metal work for my door speakers before finishing the interior.
     
  19. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Haven't had time to work on the truck lately. I found some very small rust throughs at the outer floor board areas near the doors. I could have easily covered that up, but knew I would never be satisfied with other than a perfect repair. So, I'll be cutting and forming some small replacement panels to weld in for an invisible repair after cleaning the welds up and painting. Once I complete this welding and the changes to the inner door steel, I'll install the new interior. I'm itching to drive the truck again with the new interior installed.
     
  20. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Raining again here today, but I intend to start welding in some small pieces of metal in the floorboard for an invisible repair. Once in and painted, the insulation and carpet will be installed along with the new TMI custom seat. I have already installed the new headliner and the matching TMI dash pad.
     

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