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  1. M

    1st TBI Conversion Help Needed

    I did test the MAP - all seemed fine. Voltages were slightly (.25 volts) below the referenced voltages, but probably not enough to cause a problem. The voltage changes with vacuum which should confirm its working at there is not a leak in it. I just replaced the booster check valve it was...
  2. M

    Favorite tool brand?

    Most of my hand tools are Craftsman which have served me well. Power tools are all Milwaukee. Miller welder.
  3. M

    Favorite tool brand?

    That's called a Mityvac
  4. M

    Potential Square

    I saw that ad - it's getting blasted all over the upper Midwest. Cool looking truck and very clean. 2wd hurts it though.
  5. M

    1st TBI Conversion Help Needed

    The IAC settled to 25 when warmed up, with MAP and brake booster unhooked and plugged.
  6. M

    1st TBI Conversion Help Needed

    Oh, and the throttle and detent cables operate smoothly, no catches or hang ups. The throttle blades close nicely.
  7. M

    1st TBI Conversion Help Needed

    I tested the MAP sensor according to the link above and my tested voltages were approximately .25 volts below each of the following vacuum levels: 1.) 0 in. Hg ...... 4.7 Volts. 2.) 5 in. Hg ...... 3.9 Volts. 3.) 10 in. Hg .... 3.0 Volts. 4.) 20 in. Hg .... 1.1 Volts. I don't think this...
  8. M

    Testing for Spark PRESENCE by Yourself & in a Pinch

    That's exactly how I tested for spark in my ongoing TBI troubleshoot. I think I even have the same light. Cheers!
  9. M

    1st TBI Conversion Help Needed

    I agree the IAC doesn't make sense. Need to dig into this further. I have no cruise. Original 78 cluster. There is a JTR speed sensor connected to ECM - should not impact this problem. I double checked my brake booster and I lose no pressure when holding the brake and turning off the key...
  10. M

    Steering column and wheel complete to the rag joint

    Would you consider selling the whole cab?
  11. M

    1st TBI Conversion Help Needed

    My son bought in the fall of 2016 from a friend's father. It was sitting in a barn with a snowplow on it, presumably used for plowing this person's property. That's all the history we have. Judging on the condition of the floor, rockers, and corners its been a MN or northern plains truck its...
  12. M

    Another NP203 Question

    Me neither. Did you see the blind squirrel comment?
  13. M

    1st TBI Conversion Help Needed

    After you pointed out the vacuum issue I paid closer attention to it when driving, and I think I just caught a frame precisely when it backfired/cutout, which dramatically lowered the vacuum. When driving it since it holds a pretty steady 18-19 vacuum. It will dip when accelerating, but then...
  14. M

    1st TBI Conversion Help Needed

    The balancer timing mark is at 0 on the tab at 12 o'clock. I don't understand your second question (TDC for #6.) I don't recall another tab location. The power steering pump is in the way, but I will look. That tells me it isn't the original engine cover and balancer combo. But it...
  15. M

    1st TBI Conversion Help Needed

    Hmmmm, this is interesting. My TDC is at 12 o'clock.
  16. M

    Another NP203 Question

    Right! Even a blind squirrel finds a nut once in a while.
  17. M

    Another NP203 Question

    Was able to take the truck for a drive. Get this....the unit the crotchety old salvage yard guy said he "guaranteed was unconverted" is a part time shaft converted NP203. I thought the output shaft to rear diff assembly looked different. Definitely no crown gears so not that crappy part time...
  18. M

    1st TBI Conversion Help Needed

    Could be that despite being basically the same they re-numbered the part. This happens often with change in models, etc. I don't think I'm going to change anything there.
  19. M

    1st TBI Conversion Help Needed

    I reset the IAC for like the 10th time, fired the truck up and it idles ok...the symptoms now are kind of back to where they were. It doesn't fire right up, kind of have to goose it a bit. But it is driveable. I checked timing with my flashy new timing light and it was perfect at 0 degrees...
  20. M

    1st TBI Conversion Help Needed

    No - should have I?
  21. M

    1st TBI Conversion Help Needed

    I did this on the old hacked up junkyard harness, but not on the new AFI harness. That's a good thought. Since I had the timing set and I didn't observe the guy setting it, I'm gonna pick up a test light and double check timing. for as much as it backfires through the throttle body it suggests...
  22. M

    Another NP203 Question

    We did the swap this weekend but I didn't' have a chance to drive it due to some TBI issues I'm working through. Interestingly the unit we took out did have the thrust washers and bearing like in the picture above. I did not transfer them over to the replacement unit because the end play felt...
  23. M

    1st TBI Conversion Help Needed

    I did not do the TPS learn. Put in a new IAC and did the relearn on that.
  24. M

    1st TBI Conversion Help Needed

    I've used up a can of ether checking for leaks. The first adaptor plate I tried was a thin piece of junk. I sent that back and got the thicker Holley plate - it's 1/2" thick and worked great.
  25. M

    1st TBI Conversion Help Needed

    The fuel pressure regulator makes sense. Is there a relay involved, or how do I power the fuel pump absent TBI control? We put this system on an original 4 barrel carb intake. Used the Holley adaptor plate.

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