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Any suggestions on how to set the economy and power stop on a 1965 fuelie? I don't have a manometer and that is all any manual talks about using. I can't find a manual that indicates any other way of setting these stops. Any and all help is appreciated!!!!!!! Thanks Jim
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Re: No Manometer - What to do?
The stops can be set fairly accurately with a Mity Vac and fine tuned by road testing. I gotta go look up the vacuum numbers, the economy stop is 8 or 9", but I don't remember the power stop setting. I'll get back to you. -
Re: No Manometer - What to do?
Rule of one thirds easy way to remember: 3,6, 9 then fine tune.fgood luck, mikeComment
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Re: No Manometer - What to do?
I suggest you first set the stops to give the right discharge pressure at the nozzles with a known volume of air entering the FI. The easiest way to do this is with a manometer. Then you can adjust the enrichment diaphragm rod length to make the lever leave the lean stop at 9 inches. To just set the stops according to vacuum readings on the enrichment diaphragm (using what rod length?) is not going to result in the right nozzle pressure unless you are incredibly lucky.
You will probably have the opportunity to buy a used Kent-Moore FI manometer kit on eBay several times this year. They usually sell for around $500. You can buy new aftermarket Mercury and oil manometers on the internet from instrumentation companies any day of the week. You can even hire a Corvette FI rebuilder to set your stops using his manometer and test engine for $200.
But I admit, some folks try to set everything from main bearing clearances to wheel alignment by trial and error, so why not an FI unit?Comment
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Re: No Manometer - What to do?
Here's the drill: Connect a vacuum source to the enrichment diaphram. If you had a cranking signal valve, you would want to disconnect it, but since you have a 380 unit this isn't necessary. The ratio lever should be pulled dead against the power stop. Apply 3" of vacuum and set the power stop so that it just touches the ratio lever. increase the vacuum to 9" and set the economy stop so that it just touches the lever. ASSUMING everything else is ok with your unit, it should be pretty close with these settings.
To fine tune, try the car on the road, preferably a back road where you can pull off frequently and give the screws a quarter twist. Lean the economy stop until the car starts to stumble or hesitate a little. Then richen a quarter turn. Richen the power stop until you see a bit of black smoke on acceleration. Lean a quarter turn, and you should be good to go, again assuming the unit is properly operating.
If the unit is badly out of calibration, these adjustments probably won't get it going. The idle air and idle fuel also need to be in sync. This proceedure is covered in the ST12. These are not the only adjustments that may need to be made. If the unit needs major adjustment it might well be worth the excess stomach acid to send it to someone like Jerry Bramlett who can put the unit on a test engine and do some of the more in depth adjustment and repair that could be necessary.Comment
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Re: No Manometer - What to do?
You might give some consideration (after all well intentioned suggestions) to getting in the car, driving the sucker, adjusting the stops, and going about life in whatever lane you are in. I believe the economy stop is the most important adjustment - because that is the adjustment you live with going down the highway - 24 hours a day. The power stop only addreses issues you face when you need to cross the finish line before Mikie # 14 does. That's easy. Work on the 24 hour adjustment...Comment
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Re: No Manometer - What to do?
I rebuilt this unit myself over the winter with alot of advice from John Degregory, it went very well and the car runs alot better then last year. I will try the vacuum adjustment because I do have a mity mite. The thing I don't know is - how will the car run if the economy and power stops are not adjusted properly? Right now the car seems to stutter a little around 2500 to 2900 RPM.
Thanks for everyones input!Comment
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Re: No Manometer - What to do?
Jim, you don't mention the vacuum condition that you are experiencing at the 25-2900 RPM speed. Is it acceleration or "cruise". If it's an acceleration issue, I would suspect the power stop is too lean. If it is a high vacuum condition, such as steady cruising, I would suspect the economy stop could be too lean. This is all assuming that the ratio lever is operating properly, nozzles flowing ok, etc.Comment
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Re: No Manometer - What to do?
The surging is at a cruising speed. I checked the unit for nozzle flow and leaks 5 times before I reinstalled it, nozzle pattern is fine. I think it is probably a lean economy stop as well. Vacuum on the unit at idle measured 12-13 inches. Timing is correct - 12 degrees BTDC. Idles (cold start) 2200-2400 RPM
After warm up idle is 930-1,000 RPM although the gas pedal itself somtimes causes it to idle at 1300, it seems to bind, if you pull the rubber gas pedal itself toward you or off the metal accelerator shaft the idle drops down. Can't for the life of me figure out how its binding. Acceleration is instantaneous, no hesitation there.Comment
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Re: No Manometer - What to do?
Try richening the economy stop in 1/4 turn increments and see if the problem goes away. I suspect it will. As always, with any FI problem, be absolutely sure the ignition system is not the real culprit. Doesn't sound like it is in this case, but ignition is the main source of most perceived injection woes. Dunno about your accelerator linkage, i'd try disconnecting it from the unit until I got everything adjusted and then start working backwards through the linkage. Fast idle doesn't need to be more than about 15-1800 RPM and should come off pretty quickly unless you are in a real cold climate.Comment
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Re: No Manometer - What to do?
Thanks Ed, I will try adjusting it later today. As for the ignition I have new correct plug wires & plugs, restored distributor by Don Baker and new coil and Capacitor. Over all its in excellent condition. The only thing I didn't check was for wear on the lifters which may indicate a worn cam. My rockers are all adjusted for the .030 gap. Compression is great also. Adjustment of the stops are the only thing left to do I hopeComment
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Re: No Manometer - What to do?
Jim, Brian Futo had an article in an old Restorer that gave an excellant how to on setting up the unit with a vacuum guage for the initial. I can't stress getting dwell and timing dialed in enough first though, as almost every unit I set up on a manometer has to be adjusted for timing and dwell first, and then runs great with the manometer just refining it. Good luck. PaulComment
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