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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
    With the weather now in the teens frequently, I decided it was time to re-visit the fuel settings on the GMC. With no intake heat on the tall single plane intake, I knew there would be no quick intake warmup for best fuel atomization. However, the engine still started perfectly in the cold, and warmed up very nicely in warm weather. One problem, in the low temperatures the cold engine would die and stumble after giving it some throttle and then quickly letting off the throttle in neutral - if you didn't allow it to warm up at idle first in these cold temperatures. I've pulled the idle A/F back to 14.0, and reduced the cold enrichment fuel six points - since richer idle A/F mixtures than around 14.4 - 14.6 have always left signs of gas fouling at the plugs at cold start in warm weather. I also reduced cranking fuel four points, but warm starts are still perfect in cold or warm temperatures.

    Problem two was I still was getting a spot of oil on the inner ceramic of some plugs at times after WOT. I determined this had nothing to do with my 14.7 cruise A/F or the lean idle A/F, and was not due to my timing. It also had nothing to do with the cylinders or heads. I adjusted WOT one tenth richer to 12.6 - and that problem seems to have disappeared.

    Accelr fuel has never needed any adjustment and still hasn't. So, I've left it alone.

    I'll have to see how the engine reacts to these changes over the next few days in cold starts. As far as driving, the truck still runs perfect.
     
    Last edited: Feb 8, 2018
  2. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Man, this is sickening. My right hand fuel tank is full of fuel, but the engine began running worse and worse. I switch to the left hand tank and everything begins running normally again after a minute. The truck is running like it has a tank full of water every time I switch over to right hand tank. If I catch the culprit, they won't make it back off my property again. Now I have to review security camera footage.

    Update:

    Well, nothing so nefarious as watered down gas by some prankster. The fuel filters were a little dirty, so I changed them. Then the truck wouldn't start at all - no ignition spark. If something hasn't happened in the distributor or coil, something has failed with my MSD 6T. If the 6T has failed, it looks like it's time for a new FAST ignition box. Murphy's law really knows when to give me a kick. What is really strange, was how the engine acted up every time I switched on the right fuel tank and how everything cleared up a minute after I would switch back to the left tank. Gremlins, evil fairies, Joe Btfspik, some curse?
     
    Last edited: Jan 15, 2018
  3. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Anyone know if the FAST E6 is compatible with the MSD canister style Blaster 3 coil? Or, will I need to use the E92 coil?
     
  4. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    The FAST E6 with E92 coil kit is on its way. Summit rep says the Blaster 3 coil should be fine with the E6. I'm going to try for a more definitive answer from FAST tech.
     
  5. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    FAST tech says the MSD 3 coil is fine for use with the E6. So, I can keep the MSD 3 coil in place on the intake and change nothing but the box..
     
  6. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Should have had my new FAST E6 today, but UPS was scared to come out - no snow, no ice, just cold weather. Too cold for me to install it anyway - but not having the truck running in this cold weather is keeping me from optimizing the new idle A/F and cold start settings.:(
     
  7. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    I didn't check my antique 6T out much beforehand because it really needs to go back on the car I took it off of - with its other MSD box connectors - Engine Builder's Delight, timing computer, and other timing controls. Once I had it off, it checked out good. The stinking fairly new MSD Blaster 3 coil was bad - after only several hundred miles of use, yet out of warranty date of course. So, I will be building a bracket for the FAST E92 coil and using it. I did get the new FAST E6 mounted and wired - and the engine started but began acting the same as before, in seconds, using the MSD coil. The FAST E6 box is slightly longer and much heavier than the MSD 6T and 6AL boxes - if that means anything..

    The good thing - I don't need to send the MSD 6T in for repair. I'm also glad the MSD coil failed in the driveway and not on the road. :D Hopefully, it will be warm enough Friday for me to mount the new E92 coil, and start checking my new idle F/A settings again.
     
  8. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Back to the drawing board. I didn't like the way the larger E6 looked where the smaller MSD 6T had been. I've decided to mount the new coil in that space for a less crowded look. My loaded '81 GMC doesn't offer many neat placement choices for the E6, So, I'll be lengthening wires and installing it inside the cab. I actually have a stereo amplifier system oversized battery supply behind the passenger side front seat I can tie into for the E6 main power. There is plenty of room for the E6 behind the driver side. The other E6 wires will run neatly under the carpet and through the firewall - making the wiring even cleaner and neater under the hood. This also means I'll be able to more easily see the E6 diagnostic LED if and when needed - and the E6 will also be well insulated from any electrical noise. I have a MSD noise capacitor I'm also going to use with the E6 main power wires.
     
    waybad1 likes this.
  9. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Little aggravating things have been interfering with getting the new E92 coil installed. First, one of the coil bolts was defective - FAST took care of that quickly. Next, when I tried to put a second coat of paint on my new bracket, the original paint on the sheet metal wrinkled up. I cleaned it up after it dried - down to the bare metal this time, and painted it back perfect. Just waiting for the paint to dry in this cool weather before re-assembly.

    While on hold for the paint to cure, I removed the MAP adapter and early style GM MAP I was using, and installed a new eBay $8 MAP into the throttle body. That beats the pants off paying $50-$60 for one elsewhere - I'll just see how long it will last. The 355 small block makes good vacuum at idle and doesn't have the problems I had with a dual plane intake or relatively high cam overlap. The new MAP was a good fit, looks good, and read correctly when I powered the system on with the key. The throttle body and intake looks better now without the old style GM MAP and its bracket..

    The previous coil wire was too short, so I had to make a new one from some of my left over MSD wire kits. Facetiously, lucky me. But, I probably don't need to be out in the cold very much at my age. So, I'm just plodding along at a slow pace a little at a time. Still haven't decided on just where I want the E6 mounted behind the front seat - since I'm now involved in replacing the old interior with a new custom interior and added insulation. Considering what my new Silverado cost, I might as well have the old GMC just as nice as it. I like the Silverado because it is new, but my GMC will run circles around it - and I enjoy driving the GMC more.

    The 1866 originator of Murphy's Law must have somehow known I was on the way.
     
  10. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Murphy's Law is still dumping on me. Installed the new E92 coil and wired everything back up. The truck started... and then promptly died. I could only get 22 PSI of fuel pressure showing, so I swapped the fuel pump out with my spare. Still couldn't get but 22 PSI of pressure. Cracked open a throttle body line and saw the pressure bleed - mostly air. As I traced all my tank lines, I finally saw the very slightest sign of a wet crack at my fairly new BDW FSV3 tank switching valve. As soon as I tried to remove the hose, the port snapped completely off.

    The good news was the local auto parts did a warranty replacement of the $64 part. I still have no idea how or what broke the first BDW valve. All I know is it must have cracked in some earlier 17 degree weather last week - while sitting parked. The parts guy said the valve should not have broken like it did. So, maybe it was just a housing flaw in the FSV3.

    At least I have spark again.... and maybe fuel again- once I get the new valve installed. Installing the thing is a real PITA.
     
    Last edited: Jan 25, 2018
  11. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Installed the new FSV3 today. Still didn't get any fuel from the right hand tank, so I put fuel into the left hand tank and switched to it. Built fuel pressure and cranked the engine. The engine ran sweet like it should. I then thumped the bottom of the right hand tank, I had topped off recently. The tank should have been at least 3/4 full - it was bone dry. I now believe someone drained the tank from the hose below - and that is how my FSV3 port was broken, and how they got past the locked tank caps. There's no way I burned a tank of fuel in two starts for only a few minutes both times - and the tank has no leaks. I've had all my PTZ security cameras positioned to watch for deer - one will be watching my vehicles outside from now on.

    The new $8 throttle body MAP looks to be working perfectly. Now, I need a 20 degree morning to see how my new idle F/A and enrichment changes are working. It's hard to tell, but the new FAST E6 and E92 coil appear to have smoothed the engine idle during warmup - over the MSD 6T and the Blaster 3 coil, when that coil was still working good.
     
  12. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    I've also purchased new protective sleeves for my plug wires, since they all run behind my engine and up underneath the headers. That should insure there will never be any rubbing damage to the plug wires.
     
  13. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    I've been having a large shower bath re-tiled in my home - three days into the install last week, the folks found they had mis-figured the amount of ceramic tile. They just finished today - a week later. Between that and other things, I just got a chance to work on my GMC this morning. I got the FAST E6 mounted and wired behind my drivers seat and fired the engine. After some cold enrichment changes the engine began running sweet at 14.0 A/F (-6 cold enrichment). I'll finally be getting to work out the new idle A/F, cranking fuel, and cold enrichment settings. Warm start has always been perfect, so cranking fuel will probably take a very slight change if any. I may still need to lean the idle A/F back leaner where it was previously. At least the engine is still perfectly happy with the 12.6 WOT and 14.7 cruise A/F. The timing looks perfect now.

    Got my #14 Buck, this year, last night - 14 large deer were prancing around in my orchard next to the house last night. Wish I could have dropped them all. So tired of having my fruit trees and shrubbery destroyed.

    If possible, I'll get the new protective plug wire insulation on tomorrow. The time for the new custom interior is drawing nearer every day for the '81 GMC. I also pulled my '55 Buick Special out and started getting it ready for extensive new upgrades today.
     
    Last edited: Feb 8, 2018
    waybad1 likes this.
  14. waybad1

    waybad1 Member

    Joined:
    Jan 22, 2012
    Location:
    Ventura CA
    What protective plug wire insulation are you using?
     
  15. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Since I only need to protect the wires from rubbing in the firewall area, I'm using some large diameter 2 foot long DEI shrink tubing and 1" Ron Frances BS10 braided plastic wire covers. Eliminates several of the MSD wire separators I was using and fully protects the wires from rubbing damage. Will look neater and more factory also. I will only extend the covers forward past the rear of the block (near cylinders 7&8).

    If I had needed heat protection, some good header wrap would do a nice job.
     
    waybad1 likes this.
  16. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Still raining here and more predicted. Isn't helping my arthritis any, but I took some medicine and started feeling better for a while today. While easier, I crawled under my home to see why the tub in my newly tiled bath was so slow to drain. The $1100 I paid a professional plumbing company to repair that drain, several months back, was a waste of time. The guy replaced drain plumbing that had never been a problem, and hadn't touched that original incorrectly installed tub drain I had called in for to be correctly repaired. Even the new drain fittings and pipes he installed were leaking. I'm no plumber, but I cut his garbage out and repaired everything correctly while replacing the tub drain correctly. I now have that bath draining properly for the first time since my home was built - and drain plumbing that had never leaked before no longer leaking.

    Anyway, I'm going to pull something out of my garage and cover it, just so I can get the GMC inside to work on. I have use for the GMC as soon as the interior is in again, and all the new wiring protection is installed - need to have four new tires mounted and balanced at a local tire store for another project, and I don't have room in the short bed of my Silverado for them.
     
    waybad1 likes this.
  17. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Drove the truck yesterday to fill up the driver's side tank, and it felt great - but only after warmup. Cold start was too rich and fouling the plugs while at idle. This morning, I bumped idle A/F to 14.1 and cold start idle was still too rich even with the previous -6 cold enrichment. Reset idle A/F to 14.2, keeping the -6 cold enrichment, and the engine smoothed out. I'll keep it there for now. I also switched to 89 octane mid-grade Chevron yesterday. A warm engine part throttle jab yesterday of the accelerator pedal lit the tires up from a ten mile per hour roll, and it's also breaking loose some every time I turn onto a highway from a stop - I'll have to start working to improve traction. Some 70/30 front shocks and better 50/50 shocks on the rear should help.
     
  18. 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
  19. 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.
  20. 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.
     

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