Not sure this is exactly the same, but Dino over on the strokers group is in Saudi Arabia. He has an exprot 90's XJ. It runs off of MAP,coolant, etc; no O2 sensor on it at all. I would imagine the ecu from it would allow running even leaded fuels without too much problem. He uses a map voltage adjuster and some other tricks to alter the fuel curve to go with its stroker and 24 lb Ford injectors. -- Mark Price Morgantown, WV 1969 AMC Rambler, 4.0L, EFI, T-5 -------------- Original message ---------------------- From: adh@xxxxxxxxxxxxxxxxx (Sandwich Maker) > " From: Tom Jennings <tomj@xxxxxxx> > " > " On Mon, 2 Apr 2007, Sandwich Maker wrote: > " > " > " From: Tom Jennings <tomj@xxxxxxx> > " > " > " > " The only thing I've read "bad" about Howell and others is from > " > " people who tried to set them up without enough sensor feedback, > " > " "open loop", and feedback is the whole POINT of FI. Except for > " > " those few, I've not heard a bad thing about Howell. > " > > " > i disagree about feedback. it's the only practical way to zero in on > " > perfect mixture under widely and wildly changing conditions, but i've > " > always thought that to a degree it was a crutch for systems that > " > didn't have the proper sensors to read the environment going in. > " > " I was specifically referring to non-OEMs adding EFI to an > " engine that's either older, modified, rebuilt, customized, > " or otherwise not-factory-unit-to-unit consistent. > " > " Saab designed a limited feedback FI system for some particular > " engine coming off an assembly line with probably good consistency > " unit to unit. That's not what hobbyists are doing. > > agreed, though saab didn't design this system - it was the original > bosch jetronic first seen on the '66 vw squareback. afaik it had -no- > feedback. > > " Isn't it funny though, that a carb basically has one "sensor", > " an air-velocity/partially-mass measuring device aka venturi, and > " with that one crappy old thing meters gas pretty damn well over > " a surprising range of variables. (OK power valves etc count.) > > don't forget 'booster' venturii! > > " Carbs are lousy at: engine (coolant) temperature compensation, > " economy/partial throttle cruise vs. power "modes", and > " altitude. Chokes and vacuum or progressive-mechanical secondaries > " pick the low-hanging-fruit of the first two, and there's some > " 80's carbs that attempt altitude but we don't hear about those > " any more! > > this is all why a simple open-loop system like the jetronic worked so > well. the only thing it couldn't measure was humidity. > > " > this was btw an > " > analog system, based afaik on bendix patents that may have been on the > " > '57 rebel system. > " > " It would be very interesting to re-visit those older analog > " systems with the electronic gunk we have now! Too bad the > " hardware is all museum quality and availability now. Analog > " servo stuff is something I'm good at (useless skill). > > analog stuff can take real math skills which i think is why it's > gotten passed over, but i think it's a shame. the elegant simplicity > of it all... > ________________________________________________________________________ > Andrew Hay the genius nature > internet rambler is to see what all have seen > adh@xxxxxxxxxxxxxxxxx and think what none thought > _______________________________________________ > Amc-list mailing list > Amc-list@xxxxxxxxxxxx > http://www.amc-list.com/mailman/listinfo/amc-list _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list