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MALFUNCTIONING IAC???

Discussion in 'FAST Support Forum' started by 78 F150, Aug 9, 2018.

  1. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Any compression and leak down tests will be more accurate after the engine has been running again. This will only relate to the ring condition since the valves aren't leaking on the seat. I doubt you have any bad rings - which would have showed oil fouling on the sparkplugs. So, this step isn't needed now.

    After the final head torque, concentrate on intake to head matching and correct pushrod length. Depending on how much was shaved from the heads, the intake could require some machining to compensate.
     
  2. 78 F150

    78 F150 Member

    Joined:
    Feb 6, 2013
    Talked to a guy about welding my bell housing and long story short I'm going to try to find another one. I think I found one in a wrecking yard 45 minutes from me but they won't have it pulled for about a week or so. So in the mean time I wait.

    Almost got the mounting bracket done for the hydroboost unit. Just need to make one modification.

    The engine is all back together except for the headers and p/s pump. Waiting to bolt the headers on until I get the tranny back in. Hoping to get the tranny back this week, but there's no hurry until I get the bell housing. So I'm kind of at a stand still right now for about a week or so.
     
  3. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    You could also get a new steel replacement bellhousing, but these sometimes require some alignment work to correctly position on the back of the block. One thing, steel bellhousings are safer and usually last forever (barring a clutch explosion). Lol, I looked on eBay and the cheapest cast iron housing was $250. Aluminum was over $400, and steel SFI rated was over $700. The last SFI approved steel Ford bellhousing I bought was Lakewood around $300 - that's been a long time back. Inflation never stands still.

    Summit has this one on sale - https://www.summitracing.com/parts/qti-rm-8011
     
    Last edited: Apr 10, 2019
  4. 78 F150

    78 F150 Member

    Joined:
    Feb 6, 2013
    So the wrecking yard called me back yesterday and told me they found another bell housing they already had pulled out of a vehicle so I drove over last night after work and picked it up. Only cost me $75. So now I just need to get my tranny back and then I can start putting it back together. Things are coming together slowly.
     
  5. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Look at the bright side - it's still light years faster than the heads came back. Good score on the bellhousing.
     
  6. 78 F150

    78 F150 Member

    Joined:
    Feb 6, 2013
    Yes, very true...LOL. So I got the tranny and t. case back today. Also dropped the bell housing off at the machine shop to be cleaned in the hot tank. Will get it back tomorrow. It's been raining almost every day and is supposed to keep raining until next week, so not sure how soon I'll be able to get the tranny back in. Hoping to install it this Sunday. We'll see what happens with the weather.
     
  7. 78 F150

    78 F150 Member

    Joined:
    Feb 6, 2013
    Got the transmission & transfer case installed today....almost. I got it sliding into the bell housing & clutch, but it's about 4" away from being completely mounted flush with the bell housing and it's stuck and won't move forward any further. So after coming in the house and thinking about the problem, it suddenly dawned on me. I used two bolts with the heads cut off on the bottom two bolt holes in the bell housing to guide the tranny in. But one of the bolts is hitting a bolt on the side of the tranny and won't allow it to move forward any further. So once I shorten the bolt, I'll finish sliding the tranny up to the bell housing. Then it's on to getting the hydroboost unit mounted and hooked up, brakes bled, and finish up a bunch of other things. Making progress, slowly. My body hurts bad after wrestling that tranny and t. case all day today...by myself. Dang, all these birthdays I've had are sure taking their tole on me. I feel like I got run over by a truck.
     
    Last edited: Apr 15, 2019
  8. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Oh, but just think - it will all be back brand new and ready for action by the time you get over the soreness. Enjoy how green all the envious people will be.:D
     
  9. 78 F150

    78 F150 Member

    Joined:
    Feb 6, 2013
    It was a huge PITA, but the transmission is officially installed!!!!! Now onto the hydroboost installation.
     
  10. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    That hydra boost should be in by now - ready to hear the 460 running. Post the audio and handheld video, and I'll post the audio and handheld video for the '85 TA's installed 406. The local Saturday Jack's Hamburger car meet is hot for me to show the car. My '81 GMC gets a lot of attention there. They still know nothing about the others I have. The TA sound byte with handheld video will be my teaser for them. ;)
     
  11. 78 F150

    78 F150 Member

    Joined:
    Feb 6, 2013
    I wish the hydroboost was installed already, but it's not yet. Wednesday I had to finish up some miscellaneous things under the truck after installing the tranny. Then Thursday and Friday it was raining. Saturday I don't do any work because it's the Sabbath. Then today I only got to work on it about an hour then we had to go to my sister's house for Easter. So today I mounted the hydro unit and started mocking up the hoses. That's as far as I got. Tomorrow after work I'll work on it some more. But once I get the hoses cut to length, I need to take them to a shop to have the end connectors crimped on the hoses. Once I get that done, then I need to bench bleed the master cylinder and then mount it and then bleed the brakes and the hydro unit. I still need to bolt up the headers, and install the plugs and wires before I can start it up. I also still need to reinstall my gear vendors overdrive, driveline and fuel tank after I clean it out. So I still have a lot of miscellaneous stuff to do.

    I look forward to seeing and hearing your videos. I'll definitely post a video once I get to the point I can start it up.
     
  12. fabr

    fabr Member

    Joined:
    Jan 23, 2017
    Adventist? JW? Just curious.
     
    Last edited: Apr 22, 2019
  13. 78 F150

    78 F150 Member

    Joined:
    Feb 6, 2013
    Adventist.
     
  14. 78 F150

    78 F150 Member

    Joined:
    Feb 6, 2013
    Nothing I do ever goes easy. Spent most of my time after work chasing brake fittings & p/s fittings. Still need to find 3 fittings.
     
  15. fabr

    fabr Member

    Joined:
    Jan 23, 2017
    Cool,I have several friends of that faith. Very good people and a healthy lifestyle to boot!!
     
  16. 78 F150

    78 F150 Member

    Joined:
    Feb 6, 2013
    Fabr--I agree with you :)

    So after 2 days of running around town (after work), I finally found all the fittings I needed to finish putting together my p/s pump hoses and my brake line. Had to do a little customizing on my p/s pump hose, but I got-r-done. So now if I can only figure out how to get the compression fittings assembled, I would have have had the hydroboost system done tonight. But no, there's always something that's got to give me problems....LOL. But once I get the two hoses assembled with the compression fittings, then all I need to do is bench bleed the master cylinder and install it. Then I need to bleed the brakes and the p/s system. My goal is to have the truck running by this Sunday at the latest. We'll see what happens.
     
    Last edited: Apr 23, 2019
  17. 78 F150

    78 F150 Member

    Joined:
    Feb 6, 2013
    Got the truck fired up today!!!! I recorded 4 short videos. Let me know what you think and what adjustments I need to make. Haven’t taken it for a drive yet as I needed to bleed the brake system and I ran out of time today.

    I reset the ECU before I started the engine and set the idle a/f at 13.5 (default setting), cruise a/f at 14.3, WOT a/f at 12.6. With that said, when I took the heads off the engine, I noticed a lot of carbon/oil on the pistons and the inside of the headers were black. This is a sign it’s running really rich, correct??? That might be why the engine feels sluggish??? Henry said the back of the valves in one head had a lot of oil on them due to some low quality valve seals that were installed by the machine shop when I had the valves back cut a while ago, which he replace with better quality seals. The other head had good valve seals and there wasn’t the oil on the back of the valves. Henry thought this oil leaking past the valve seals could have contributed to the crazy a/f ratios. Is that possible? It makes sense to me since the O2 sensor would have been reading oil in the air. Who knows, I’m just hoping it was part of the problem I guess.

    I noticed my fuel pressure is only 33 psi with the engine running. I adjusted the regulator before I tore the engine apart and I made sure it was at 43 psi. Now it’s at 33 psi for some reason. Looks like I need to adjust it again. I’m suspicious of this FAST regulator as it seems to be doing some weird stuff and I have to keep adjusting it for some reason. It also bleeds down a lot faster after I shut the engine off than it did when it was new. Remember I found a slight vacuum leak in the regulator? Could that be the reason I’m seeing this weird stuff happening? I’ll continue to keep an eye on it.

    I think I got the fuel tank cleaned out pretty good today. There was a bunch of black stuff stuck to the top/roof of the tank, so I took some chain and put it in the tank along with some water and sloshed it around quite a few times and emptied it out. From what I can tell it looks like I got 99% of the black stuff out. We’ll see what my filter looks like when I drive it a few times.

    FYI….I have the new adjustable vacuum advance canister installed. Timing is set at 18* at idle. The only vacuum being used is for the fuel pressure regulator and the vacuum advance canister, both sourced from the throttle body. My power brake booster is no longer installed, as it’s been replaced by a hydroboost brake system that functions off the p/s pump.


    4/28/19 HEADS REPAIRED VIDEO (1)

    4/28/19 HEADS REPAIRED VIDEO (2)

    4/28/19 HEADS REPAIRED VIDEO (3)

    4/28/19 HEADS REPAIRED VIDEO (4)
     
  18. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Well, the engine needs a complete re-build! Just joking - this is the first time you've had completely normal readings and operation.

    The new, more powerful, alternator should correct the lower voltage readings higher. But, the battery could just need exercise to remove sulfation after sitting so long.

    What you can work on is only slight fuel corrections after driving and reading the plugs. Actual driving will now give correct fuel maps. One tenth correction to idle and cruise A/F are all you will do to find optimum. Idle and cruise A/F readings look good now and all you should need is some enrichment changes as needed for best cold and warm start, and acceleration - if at all. WOT at 12.6 would be a good setting.

    You can get better fuel mileage by increasing the idle and vacuum timing as much as the engine allows without pinging or plug overheating. Only work at this later. This will include some fine tweaking of the fuel and enrichment settings again after finding these timing settings. WOT should be somewhere between 12.5-12.7, no more and no less. You'll then be able to find the ideal WOT under full throttle application. You'll need to check these by carefully watching plug condition - just don't go crazy and damage the threads!

    Good job. FAST score A+. :D
     
  19. 78 F150

    78 F150 Member

    Joined:
    Feb 6, 2013
    Normal readings?? What?!?! Those words are foreign to me…LOL. So does this mean that the problem I was having was in the heads/drivetrain? I know the vacuum advance canister was a problem also, but even after I replaced it with the new non-adjustable canister I got from Autozone, the readings still showed a problem (have since replaced the Autozone canister with the adjustable canister I got from Summit). So that tells me the problem was in the heads/drivetrain, correct? Maybe the valve seats being out of round, the marginal lifters & springs rates, and the inferior valve seals (on the one head) combined with a bad vacuum advance canister were the issues??? I’m guessing the out of round valve seats were a major cause of my issues. If the valve wasn’t sealing on the seat due to it being out of round, that would have the same effect on the vacuum of the engine as bouncing valves would have, right? It would affect the vacuum of the engine, which in turn would affect a/f ratio because it was reading as if it was lean or a vacuum leak??? Is my logic on the right track?

    You said this was the first time the readings looked normal. However to be honest, I can’t tell the difference with these new readings compared to my old readings. That tells you I have no idea what I’m looking at when watching these numbers bounce around on the screen. I can’t tell when there’s a problem because I don’t know what the numbers are supposed to be in the first place or how the readings are supposed to act. This is frustrating not knowing what I’m looking at. What I really need is a class on EFI so I can learn what all these readings & numbers are supposed to be. In the meantime, can you explain to me which readings are now looking normal that wasn’t looking normal before? Maybe explain what you’re seeing and how it’s acting now and compare it to the way it was reading before? I still have some of the old videos, so if you can point out a detailed explanation of each of the readings I have now and tell me what they’re doing, I can go back and compare it to the old video and hopefully it will educate me on what to look for with the readings. It might help me identify a problem in the future.

    It seemed that from the startup in the 1st video to the last video the idle a/f ratio looked like it was calming down a little bit. So with some driving and learning, it will dial itself in and function like my Autometer O2 gauge functions. That Autometer gauge a/f readings looked just like your readings on the video you sent me a few weeks ago and that’s what I’m hoping my FAST a/f readings will look like. I want to find your video and watch it again and compare it to my readings….Question, what are your idle, cruise, & WOT a/f ratios set at on your GMC? Are you running 13.5 idle a/f? Isn’t your cruise a/f pretty close to 14.7??? I know mine won’t be the same as yours, but I’m just trying to get an idea if I’m in the ball park because you have yours tuned perfect.

    So it looks like I need to learn how to read spark plugs. Just like the readings on the handheld, I have no idea how to read a plug and what the different colors mean and more importantly, which way to go with adjustments. So for now my plan is to have you help me tune this thing. I’ll drive the truck and then pull the plugs and take pictures or a video and post it on here and have you tell me which way to go with my adjustments. I'll need advice on which way to go with my timing also. How many miles should I put on these new plugs before I pull them and take pictures of them? I’m hoping to drive it tonight after I readjust my fuel pressure regulator back to 43 psi and make a small lifter adjustment.
     
    Last edited: Apr 29, 2019
  20. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Your fuel pressure is set to 43 with the engine not running - it can be lower after the engine is running. (my GMC is usually around 36 idling) Be sure to clean the FAST bronze filter with Dawn or something similar. Be sure to set the IAC and TPS after the engine has fully warmed. These will change some as you make A/F and timing changes and while the maps build correctly.

    You started out with so many issues, it was difficult to determine all the problems. That's why it took so long. They've all been corrected now. You could view all your videos to see how corrections improved the readings. The FAST installation instructions can guide you now that you no longer have multiple issues. It's very unlikely you would ever have multiple issues like that again. I could see the worst of the head problems looking at your plug side electrodes. You'll be able to use this and the upper and lower coloration of the center ceramic electrode to optimize timing and F/A now.

    Your current handheld and timing settings are very close to optimal now - close enough you should have no worries driving. Further adjustments will mostly just improve fuel mileage.

    Here's the link to my GMC handheld video (before I toned down the exhaust) - https://www.youtube.com/watch?time_continue=57&v=9IG2q9yL-zA
     

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