enblethen
Moses Lake, WA
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That is NOTcorrect!
180 degrees off could be the piston was not in compression stroke, but in exhaust stroke.
* This post was
edited 04/03/23 11:41am by enblethen *
Bud
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Pace Arrow
2003 Chev Ice Road Tracker
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OutofTime
Florida
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I did indeed have the distributor 180 out. Using an old compression tester fitting I had laying around I identified compression stroke on cylinder 1 and adjusted the distributor accordingly. After doing so the engine fired right up.
However... still the same issues. Popping, running extremely rich, falls on it's face when you attempt to rev. This is with using all ACDelco ignition basically and ECT.
One thing I noted is when I first got it running it was at around TDC, and no popping from the engine. After adjust the dizzy slightly to get timing to 4 BTDC the engine now pops with little backfires at idle.
Plugged the advance back in and computer advance is working as it should.
There's a fairly sizable difference in how the engine wants to run when it moves from open loop to closed loop. I can't do much more digging until I swap out the water pump and fan clutch as there isn't much coolant in the engine.
Based on what I saw with the engine popping, I'm wondering if the balancer has slipped a little and the engine is too advanced when you set it to 4 BTDC... thoughts?
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enblethen
Moses Lake, WA
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I would say no on the vibration damper slipping.
Is popping through intake or exhaust?
Intake would be too far advanced, exhaust is ********. (opposite from advanced)
One tooth off on distributor one way or another!
* This post was
edited 04/03/23 08:31pm by enblethen *
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OutofTime
Florida
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enblethen wrote:I would say no on the vibration damper slipping.
Is popping through intake or exhaust?
Intake would be too far advanced, exhaust is ********. (opposite from advanced)
One tooth off on distributor one way or another!
The popping sound comes from the TBI, so intake.
That would line up with my thought that the engine is too advanced right now.
You've mentioned in several posts you think the dizzy is a tooth off. That doesn't make sense to me. If I can get the dizzy to point at the cylinder 1 terminal on the cap and the balancer is at 4 BTDC while on the compression stroke, how can it be off a tooth?
If I have room to adjust the dizzy by turning it by hand and I can bring it to within factory spec, how is it off?
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OutofTime
Florida
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Doing some more thinking about it, if I'm a tooth off as you claim, then to fix the advance problem the dizzy needs to move one tooth counterclockwise, correct?
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enblethen
Moses Lake, WA
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Yes, one tooth.
Remember that the oil pump runs off the distributor shaft. The distributor will not drop completely in until engine turns over to align shafts. I like to do this with socket on vibration damper retaining bolt.
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udidwht
Renton Highlands, Wa.
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Be sure that once you confirmed the dizzy was out of position that you correct reoriented the wires in their correct positions.
1994 Fleetwood Southwind Storm
P-30 chassis 7.4L 454 TBI 58,301 miles and counting....(as of 06/08/19)
VIN# 1GBJP37N4R3314754
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OutofTime
Florida
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enblethen wrote:Yes, one tooth.
Remember that the oil pump runs off the distributor shaft. The distributor will not drop completely in until engine turns over to align shafts. I like to do this with socket on vibration damper retaining bolt.
Riddle me this then. As I've been moving the dizzy around, I've moved it by lifting up on it just enough to spin the button and then move it clockwise just enough that it will fully seat against the intake. So when I say move one tooth counterclockwise, I mean that I would "walk" the dizzy all the way around then stop one tooth shy of it's current position.
Are you saying that instead I should try to move it one tooth back, then spin the engine counterclockwise to get it to seat?
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enblethen
Moses Lake, WA
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No not all the way around, lift up about 1/2 ich where it clears the cam gear then turn slightly in the direction. The distributor will not drop all the way in until it aligns with the oil pump.
Odds are you are dropping it back in the same place!
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OutofTime
Florida
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After much research and reading much spirited debate online, I've concluded a TBI dizzy with electronic advance cannot be a tooth off. Not possible. What it can be is wires setup in such a way that you can't rotate the dizzy hat enough to get the engine in time. In that situation you would need to adjust the dizzy a tooth so that things will work out.
There are some early Ford TPI fuel injected engines that need to reference the number 1 cylinder in a certain place or they won't work right. However those engine have the number one stamped on the correct tower to make all that work on the dizzy hat.
The origin of a dizzy being a tooth off goes back to the early days with distributors that still used points. If the dizzy was a tooth off the points would open/close at the wrong time, leading to rough running.
All that out of the way.... I have the engine timed to 4 BTDC. After timing it to that and seeing the engine operation still acting as it was before, I decided to remove the TPS and swap it with another I had from a 350 in another vehicle.
I did check and the TPS are supposed to be the same part... in any case engine would only run with the accelerator fully on the floor with the 350 TPS. After swapping the original TPS back in it wouldn't start at all. I then read that I should have done this with the battery disconnected so the TPS 0 point would reset.
After doing the reset with the original TPS installed I got it running again.
Interestingly enough, now when I rev the engine it actually revs! Still pops through the intake but it will rev now instead of falling flat on it's face. Smoke coming out the exhaust seems to cleaned up a bit too.
Only thing I can think if is the TPS was jammed up somehow and causing issues. I should have some new injectors coming in next week that I hope will make a difference. I can stare at the spray pattern coming out of the current ones and it is not even.
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