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So… Zouave was running pretty well after all the transmission swap, exhaust, suspension and steering work, but with a couple of issues I attributed to the fuel system (timing, valves, etc, all being freshly adjusted and doublechecked).  First was a newfound tendency to “hesitate” (less a miss than a flutter) and to run lean under load between 3100 and 4000 rpm.  Not a miss, exactly, but a slightly fuel-starved flutter when stomping it.  The AFR gauge confirms that I’m way too lean under those conditions. Second, no. 1 plug is burning whiter than the others, notwithstanding good compression in all cylinders and no issues with spark plug wires.  See plug lowest in photo.image.jpeg

Basic tests of suction and delivery valves checked out OK (though I can see some corrosion in the delivery valves and intend to clean them), so I figured the basic KF unit is intact, and  suspected injector no. 1 might be underperforming.  I figured: why not send them all to Our Man Winterton for a look?  Paul confirmed that all the injectors were marginally within spec, very much on the low end, and grungy.  He reconditioned them all to close to 500 lbs:

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They look great!  

 

Given all I know (most of which I learned on the faq), one can’t expect to fix a fuel injection issue working from the front to the back.  You have to work from the back to the front.  So today I removed the fuel pickup from the tank, wondering whether the Wheeler Dealers guys had done anything to the fuel tank.  Looking into the tank, the gasoline (I have been using Florida rec gas) is a clear yellow, the tank appears to have no corrosion.  But it does sport a black film across much of the bottom:

 

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It’s not floating, but loosely stuck to the tank.  I can get a slight smear of it off the tank with a rag on a stick, but it really wants to stick.  What is it? I suspect it’s 47 year old fuel hose innards…. 

 

and it really wants to stick to the fuel intake screen!  Before brake cleaner:

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After brake cleaner.

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Also sticks a bit to the fuel intake:

 

 

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Adheres tightly, but comes right off with brake clearner and a toothbrush:

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Is that stuff further up in the fuel system?  I have the newer fuel pump, I think from a 325:

 

 

 

 

 

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33 minutes ago, 0257 said:

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I've read a lot of posts that say our cars are much happier with the old style spark plugs, such as the NGK BP6ES.  The Iridium, or Platinum plugs have caused issues for some people.  So I have read.  I've never tried those precious metals plugs. 

 

That was a fun post.  Thanks for sharing all the photos.

 

Tom

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9 hours ago, Son of Marty said:

You might try this on the fuel screen among other things.

 

79880951a.png

 

I actually bought that one.  Took a little bit to understand, but sure made my bicycle chain clean once I did.  I think I just used dish soap and hot tap water, maybe 2 or 3 wash cycles.

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Suggest you have the tank cleaned (steam cleaned?) or the sludge will be breaking loose and continue to clog the pickup screen.  It will drive you up a wall cleaning the screen many times and can leave you stranded.

 

If you pump begins to growl, check the pickup screen first.  If the pump growls with a tank condition like that, a clogged screen will cause the pump to growl.

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11 hours ago, '76mintgrün'02 said:

 

I've read a lot of posts that say our cars are much happier with the old style spark plugs, such as the NGK BP6ES.  The Iridium, or Platinum plugs have caused issues for some people.  So I have read.  I've never tried those precious metals plugs. 

 

That was a fun post.  Thanks for sharing all the photos.

 

Tom

Tom, you make a good point.  In fact, I am running 6ESs in Zouave.  I was looking for a good photo of the no. 1 plug, and must have grabbed one of the initial photos I took when it was still running the Iridiums.  Fact is, the 6ESs do burn a little more evenly, but no. 1 is still burning very white.  No air or vacuum leaks to explain why only no. 1 is so lean.

 

I now realize that about half my text and photos didn’t post.  Will continue the post below, as I have a few questions about the way forward.

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25 minutes ago, jimk said:

Suggest you have the tank cleaned (steam cleaned?) or the sludge will be breaking loose and continue to clog the pickup screen.  It will drive you up a wall cleaning the screen many times and can leave you stranded.

 

If you pump begins to growl, check the pickup screen first.  If the pump growls with a tank condition like that, a clogged screen will cause the pump to growl.

I am sadly sure you are right, Jim.

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The photo of primary importance that didn’t post last night was this one, of gas that flowed out of the front apron canister filter when I undid the supply hose at the inlet. This is after about an hour of sitting. Very cloudy, with a few particles.  I knocked the inlet end against a 2x4 and got more particles.

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Ugly.  It doesn’t appear that the black residue is the primary culprit, though clearly some black stuff there.  Anybody have an opinion of what clouds up gasoline like that?  in the tank it’s the same hue but clear.

 

To be sure there wasn’t a lot of junk in the main fuel line I blew it out with compressed air from front to back, then filled it with brake cleaner and blew it out again.  Each time I blew it into a rag strapped over the end to act as a filter.  The dirtiest it got was this grey streak, after applying the alcohol.

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The spot in upper right is where the hose exited into the rag. The streak lower left is where the rag was hanging down and continued to catch the stream.  Rag still wet when this photo taken.  I suspect there’s more in there, but bad enough to replace fuel lines?  Or just clean it one more time, run it, and keep an eye on the fuel filter?

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12 hours ago, 0257 said:

First was a newfound tendency to “hesitate” (less a miss than a flutter) and to run lean under load between 3100 and 4000 rpm.  

 

Whether or not the grunge on the screen is the culprit and fuel starvation is the result, cleaning the screen(s) is a good idea.  There are potentially 4 filters to clean or replace. My experience is complete engine failure above 4k rpms with a plugged tank screen.  Yours could be approaching that.

 

I have also found that a lean condition at higher rpms is a function of adjustment to the intermediate shaft and air screw at 3000rpm.  Adjusting those settings at 3k BEFORE adjusting at idle is recommended by many tuners. 

 

Using the injection manual, you loosen the intermediate shaft clamp and position the Dcam at the edge of 4mm hole.  BUT,  with inevitable wear, that position changes to more coverage of the 4mm hole.  That adjustment will enrichen the mixture throughout the range.  Start tuning with the cam slightly covering the hole.  You may end up with the cam covering half of the hole.

 

IMPORTANT:  Each time you re-adjust the cam and tighten the intermediate shaft clamp, ADJUST THE IDLE SCREW ON THE OUTSIDE OF THE TUNA CAN SO THAT THE CAM IS BACK TO THE EDGE OF THE 4MM HOLE. 

 

THEN your air screw is adjusted with the aid of an AFR gauge. 

 

I'm happy cruising on the highway at 14 and when I step on it,  the AFR goes to 12.5.  Idle at 11.5.  Right or wrong, I get the best mileage and performance with those settings.

 

Thanks for the kind words about the reconditioned injectors.  Cheers,  Paul. 

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Hmmm,   just saw your latest pictures.  I would clean screens, replace inline filter, discard gasoline,  and wash out the tank.  Buy the best fuel possible and a bottle of injection system cleaner.

 

The opaque fuel picture reminds me of the unusual deposit I found inside your injectors.   I've never seen white.  They are commonly coated in blackish deposits.debris1.jpg

 

Edited by PaulTWinterton
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27 minutes ago, PaulTWinterton said:

Hmmm,   just saw your latest pictures.  I would clean screens, replace inline filter, discard gasoline,  and wash out the tank.  Buy the best fuel possible and a bottle of injection system cleaner.

 

The opaque fuel picture reminds me of the unusual deposit I found inside your injectors.   I've never seen white.  They are commonly coated in blackish deposits.debris1.jpg

 

I’m betting that’s the crust of old fuel line, now that I think about it.

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Just now, 0257 said:

I’m betting that’s the crust of old fuel line, now that I think about it.

Btw, this problem didn’t really start till I ran a can of Liqui Moly.  I suspect it cut some of the black residue loose and that clogged my screen.  

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