Non existent idle after FI install

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Amskeptic
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Re: Non existent idle after FI install

Post by Amskeptic » Sat Jan 25, 2014 1:07 pm

SlowLane wrote:I was unable to pack the thick wires and insulation into the distributor body in such a way that they didn't interfere with smooth operation of the vacuum advance.
For the record, there is no vacuum advance on full throttle. Hpefully he can tell us that the timing does not exceed 28 with no hose and hits 38 with the hose . . .
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Ronin10
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Re: Non existent idle after FI install

Post by Ronin10 » Sat Jan 25, 2014 1:26 pm

Hey guys,

Out for the day with relations in town. I'll check what I can tomorrow morning and afternoon and report back in. I won't have access to my air/fuel meter until next week so the ratios will have to wait until then. Sorry for the lag.
Oscar: 1976 Sage Green Bus, Stock Motor, Solid Lifters, Manual Transaxle

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Amskeptic
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Re: Non existent idle after FI install

Post by Amskeptic » Sat Jan 25, 2014 3:17 pm

Ronin10 wrote:Hey guys,

Out for the day with relations in town. I'll check what I can tomorrow morning and afternoon and report back in. I won't have access to my air/fuel meter until next week so the ratios will have to wait until then. Sorry for the lag.
Really, after some of our assistance threads stretching into the years, we're good.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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SlowLane
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Re: Non existent idle after FI install

Post by SlowLane » Sat Jan 25, 2014 4:18 pm

Amskeptic wrote:
SlowLane wrote:I was unable to pack the thick wires and insulation into the distributor body in such a way that they didn't interfere with smooth operation of the vacuum advance.
For the record, there is no vacuum advance on full throttle.
Understood, but I wasn't trying to imply that the Pertronix had interfered with his 3400+ RPM max-advance (with hoses off) reading, but that the stiff Pertronix wires may be interfering with the correct operation of the vacuum advance under normal driving conditions by adding resistance to the mechanism (effectivey altering the spring constant of the spring that the vacuum-can diaphragm works against).
'81 Canadian Westfalia (2.0L, manual), now Californiated

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Ronin10
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Re: Non existent idle after FI install

Post by Ronin10 » Sun Feb 23, 2014 3:11 pm

Continue to struggle to find time to work on Greta. Between weather, travel for work, family commitments, restoring my son's bug, yada, yada, yada. So still running rough and will update perhaps in a week or so when I can get a break to do something about it. *sigh*
Oscar: 1976 Sage Green Bus, Stock Motor, Solid Lifters, Manual Transaxle

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Ronin10
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Re: Non existent idle after FI install

Post by Ronin10 » Tue May 06, 2014 1:01 pm

So the bug resto has been coming along very well. Greta? Not so much.

I did get some time this weekend to try and figure things out. It was more of a "where the hell was I" session, but I did experiment again with putting the old AFM on it and driving around. Two things stand out from the A-B testing. First, it definitely runs better with the original AFM (currently installed), but it doesn't idle...at all. At stop lights, I have to keep my foot half on the brake, half on the gas, feathering the gas to keep the RPMs up. Second, the full-throttle micro switch needs to be engaged when at full throttle.

Get that micro switch working correct should be straight forward. Best I can recall from the engine rebuild, it can shift forward and aft a bit in a slot. That ring true to anyone?

The idle problem sounds like a major vacuum leak, but for the life of me, I've gone over that engine so many times hunting for vacuum leaks, I have little faith that I could find it if that is indeed what's ailing Greta.

I'm hoping to sort out the idle to stable this week since Greta will be going into the body shop on Friday afternoon to repair door damage. Don't know if I mentioned that earlier, but she was crunched at 3am on a Friday night about six weeks ago from some joy riding 14 year olds. Finally got a replacement door and other parts in to get it fixed. I imagine the body shop guys would like to not have to fight the idle issue while moving it in and around the shop.
Oscar: 1976 Sage Green Bus, Stock Motor, Solid Lifters, Manual Transaxle

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Amskeptic
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Re: Non existent idle after FI install

Post by Amskeptic » Wed May 07, 2014 5:16 am

Ronin10 wrote: The idle problem sounds like a major vacuum leak, but for the life of me, I've gone over that engine so many times hunting for vacuum leaks,

she was crunched at 3am on a Friday night about six weeks ago from some joy riding 14 year olds.
Valve cover gaskets properly in place? Oil filler clamped and secure?
Block off brake booster at intake manifold. Any difference?

Friggen kids! Did they get identified and held accountable?
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Ronin10
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Re: Non existent idle after FI install

Post by Ronin10 » Wed May 07, 2014 7:14 am

The kids tried to do a hit and run, but they couldn't drive their car more than 50 feet away so they were caught. Cops ran 'em the riot act, but I doubt much more than a stern slap on the wrist happened. Upside is that I get a replacement driver door on the insurance companies dime, especially nice since mine had been hit at some point while in the possession of a prior owner.

I did check the valve covers for leaks previously (the gaskets are adhered in place by some high temp RTV) as well as the brake booster tee to find no differences, but that was in a slightly different configuration. If I can get a helper at my disposal, I'll give the filler tube and engine a once over again tomorrow night (too busy tonight) and see what I can learn.

One thought...as best as I can determine, I have an oil leak coming from either the oil filter mount or the seals behind the oil cooler. The driver's side of the engine (mustache bar, oil filter, upper surface of the heater box) has oil splattered on it, but when I stop I'll only get a few drips on the ground. Could it be that air is getting in via these regions? Seems a like a bit of a stretch, but I'm grasping at straws.

May have to reorder the to-do list for my August visit.
Oscar: 1976 Sage Green Bus, Stock Motor, Solid Lifters, Manual Transaxle

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Amskeptic
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Re: Non existent idle after FI install

Post by Amskeptic » Thu May 08, 2014 8:52 am

Ronin10 wrote: May have to reorder the to-do list for my August visit.
I am about to jump a plane up there.

Can you improve idle by actuating full throttle enrichment microswitch?
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Ronin10
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Re: Non existent idle after FI install

Post by Ronin10 » Thu May 08, 2014 9:21 pm

I was unable to sustain idle by actuating the microswitch, but I did hear a rise in RPMs when actuating it while my wife held the RPMs steady and as low as possible above idle. I take this result to mean that I'm actually running artificially lean at idle, furthering the evidence for a vacuum leak.

Moving on from there, I adjusted the microswitch mounting so that it was actuated at full throttle. I took advantage of my time in the engine compartment to replace the hooked hose running from the s-boot to the decel valve with a new one I had received from German Supply a couple months ago (it's pretty, but was expensive). I also replaced the brake booster tee with one which fit snugger than the one I had. I couldn't detect a leak in that tee, but it did feel sloppier than the previous one.

After that I did some spritzing around with carb cleaner to see if I could find anything. No luck over most of the engine, but I did notice an RPM change when spraying the one-way valve on the brake booster line. I think the valve itself is okay, but the lines seem to be beyond clamping down tight enough to seal. That may help a bit with the issue, but I tried blocking off that circuit altogether and it didn't eliminate the problem so I think there's another source elsewhere.

So off to try and find a replacement or quality substitute brake booster line.

Before I go, a question that has been niggling in my mind for some time: what initial settings for the idle bypass and idle mixture screws should I be starting with, i.e. settings where a healthy engine should run no matter what, even if it's rough. According to the AFM tuning guide, 4 1/2 turns out for the mixture screw, but what about the idle bypass screw? Stated another way, what are the typical settings for these?
Oscar: 1976 Sage Green Bus, Stock Motor, Solid Lifters, Manual Transaxle

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Amskeptic
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Re: Non existent idle after FI install

Post by Amskeptic » Fri May 09, 2014 6:33 am

Ronin10 wrote:According to the AFM tuning guide, 4 1/2 turns out for the mixture screw, but what about the idle bypass screw? Stated another way, what are the typical settings for these?
Re-read the AFM article. That 4 1/2 from bottom is ONLY if you are adjusting the wiper/black cog. It is a decent middle position that you get to establish henceforth so you have more adjustment range.
However: if you have not monkeyed with the wiper/black cog settings, 4 1/2 is likely to be painfully too lean.

There is no "typical setting". You use the available range to make your engine happy. You ask the engine where it is happy by nudging the wiper. It tells you what it likes. If the speed goes up when you nudge the wiper, it wants you to figure out how to make it run at that richer or leaner point. Then you make it happen.

Idle bypass screw? Did I call something the "idle bypass screw"? I remember an idle speed screw in the throttle body that happens to bypass air around the throttle plate, is that the one you are talking about? Anyways, the correct position for that screw is whatever gives you the correct idle speed AFTER you have the mixture sorted out. The mixture affects the speed, so get the mixture correct, then set the idle speed to as close to 950-1,000 rpm as you can achieve.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Ronin10
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Re: Non existent idle after FI install

Post by Ronin10 » Fri May 09, 2014 7:37 am

Amskeptic wrote: However: if you have not monkeyed with the wiper/black cog settings, 4 1/2 is likely to be painfully too lean.
That's a good statement that I've not been able to see/hear/find anywhere else. Knowing a functional limit like this helps me significantly. Kind of like know when I'm sailing off the map altogether.
There is no "typical setting".
Sorry, I should have been clearer. I guess I was expecting to hear a range of final settings based on what you've experienced which I could use as a sanity check to make sure I'm not trying to make adjustments in a region too far outside meaningful/practicable limits. I ask because I've seen air-cooled Vanagon guys say that 2 to 2 1/2 is commonplace for their mixture screws across a variety of vehicles. ,
Idle bypass screw? Did I call something the "idle bypass screw"? I remember an idle speed screw in the throttle body that happens to bypass air around the throttle plate, is that the one you are talking about?
Yes, that's what I'm talking about. I probably could've been clearer by calling it the "idle air bypass screw." I know it's commonly referred to as the "idle speed screw," I've just always thought referring to it as the "idle air bypass screw" is a more accurate way of describing what's really going on inside the throttle body, the speed being a follow-on effect of how much air bypasses the throttle plate.

Some research last night makes it look like I'm missing these on my brake booster line.

http://www.germansupply.com/home/custom ... at=&page=1

If I understand correctly, these go on each end of the one-way valve in the brake booster line and then the hard plastic hose slips over the ends and is clamped in place? Currently, my hose just clamps onto the barbs of one-way valve directly.
Oscar: 1976 Sage Green Bus, Stock Motor, Solid Lifters, Manual Transaxle

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energyturtle
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Re: Non existent idle after FI install

Post by energyturtle » Fri May 09, 2014 11:07 am

I've read through the post pretty well in my opinion. I failed to see anything on fuel pressure or fuel filter examination. Did the F.I. pump get installed? Its sounds very similar to my fuel starvation issues a few weeks ago. You may have mentioned these somewhere earlier in the post. Its quite lengthy, I may have missed it. If so disregard my post, just trying to help.

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Ronin10
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Re: Non existent idle after FI install

Post by Ronin10 » Fri May 09, 2014 11:14 am

FI pump and fuel filter are good. Fuel pressure good as well. Thanks for considering that.
Oscar: 1976 Sage Green Bus, Stock Motor, Solid Lifters, Manual Transaxle

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Amskeptic
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Re: Non existent idle after FI install

Post by Amskeptic » Fri May 09, 2014 5:51 pm

Ronin10 wrote:FI pump and fuel filter are good. Fuel pressure good as well. Thanks for considering that.
Yes please . . . get those rubber sleeves in the plastic tubes so the barbs have something to grab.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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