FI Power Train Transplant

Howdy.

I've got a good running 77 bus with a TERRIBLE body... picked it up for the engine tranny.

Has anyone transplanted an injected engine into another car... this one would go into one of our bajas.

Any ideas would be appreciated.

T.

Reply to
MN AirHead
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My apology...re-read my stuipd post

I'm interested in keeping the FI system.

Questions... Was this retrofit worth the work? How many things need to be connected to the bug (fuel, computer, wires etc)? If redoing the project would you spend the time again?

Timmy

Reply to
MN AirHead

Althogh there is nothing inherintly wrong with the VW fuel injection system giving the constraints of technology at the time,to get and keep it going is at best a challenge.And when the day comes(not if)that you need to replace/repair,will the part be available?Most are not.Add 30+ years of corrosion and you can see why there are so many Weber conversions around.Like VW's diagnostige plug,now commonplace,it was a good idea ahead of it's time.But when it works,it's a thing of beauty.Steve

Reply to
Ilambert

.........It's me again Steve.......

...................It's true that OEM Bosch FI components for acvws are no longer stocked at most parts places. When you do find an airflow meter for instance, the price can take your breath away. On the other hand, temp sensors can be substituted from other systems, hoses can be improvised, fuel press. regulators, fuel pumps etc. don't have to be that specific so long as they meet the proper operating specs. Injectors could be a problem but I've never searched too hard for them because inexpensive used ones are still easily obtained. The ECUs never fail as a rule. So what's not to like?

..............The market for Webers and other aftermarket carburetors for small displacement engines has probably been shrinking for quite a few years now. Who's to say that they'll still be available in the future? Dellortos are gone. Solex/Brosols are still coming out of Brazil but the future could be that they'll change like Mexico and adopt emission standards that make the Brosol a thing of the past on their new vehicles. The Japanese & Detroit car companies could equip the vehicles that they sell in most underdeveloped countries with carburetors if they wanted to but they don't. I'd suggest that more old car enthusiasts, who aren't compelled to keep their old cars 'correct', ought to reconsider the whole FI vs. carburetor issue in the light of what may be an inevitable disappearance of the aftermarket carburetor replacement business.

.............BTW.........A lot of those FI to carburetor conversions exist because too many people have been afraid to learn how to trouble-shoot an FI system when it starts acting up. The more complex digifant systems on the several waterboxers that I've owned have been amazingly reliable and haven't ever required much attention. But now, I've been struggling to understand the relatively straight forward L-Jetronic system on my 77 bug for over a year now. Still, it's been fun learning how to tweek the mixture settings, etc.

Reply to
Tim Rogers

,,,,i know...

------------------- Chris Perdue

*All opinions are those of the author of this post* "Sometimes you're the windshield, sometimes you're the bug"
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reply take your PANTS off
Reply to
Chris Perdue

If you take everything from the firewall back from the bus, plus the ECU, plus the fuel pump, you should be in good shape. You need to convert to a gas tank that accommodates the return line from the fuel pressure regulator. The air cleaner / airflow meter combination may be dificult to keep as-is. Be sure to check all hoses quite thoroughly. The entire system is extremely simple. Parts have not been a problem for me ever, in fact there are more parts available now than a few years back. The component parts are quite basic. The headtemp sensors are easy to diagnose (2400 ohms at 68 deg. F. +/- a bunch!) The airflow meters sometimes develop a groove at normal cruising speed position, but generally only if they have a zillion miles and the plastic cover has been removed so dust got in there. They are available remanufactured and prices vary greatly. Indications of a 'groove' are a 'dead spot' at cruising speed on flat road, steady throttle. Blip or release the throttle and the engine re-starts. The airtemp sensor never fails. the ECU never fails. Everything else is just extra and not really needed: Coldstart injector (the injector doesn't fail, but the temp/timer does which is part of the air bypass circuit too) Air bypass valves sometimes fail, but are simply a fast idle mechanism. Seals on injectors need replacing (slide them on - don't roll them!) Injectors can be pretty sloppy and still run good. Mostly they leak (allow fuel to spray or dribble when it's not time to.) Look for cracks in the big "S-hose" and all the attaching hoses - that accounts for probably 99.9% of FI system failures on the L-Jetronics. The throttle body wears a groove inside the bore and the throttle shaft wears an oblong hole, but still-good ones are available at wrecking yards. Just because something in yours has worn out, it doesn't mean it won't be available from a wrecking yard in good condition. If the 77 has a throttle position sensor (attached to the throttle body) sometimes those are a pain. The '78 & '79 did not have the TPS but you'll need a '78 or '79 ECU if you want to run without it (I assume.) (They plug right in)

Taking the entire FI harness, including the double relays and connections to the fuel pump, you have a power wire to the coil and a power wire from the start position of the solenoid to the double relay to power the pump during startup. There simply isn't anything else (that I can recall!)

The fuel pump, fuel rail (everything between the fuel pump and the fuel pressure regulator) fuel injectors - operate at

28 - 35 psi (actually, 2bar - 2.5bar) so that all needs to be in good condition. The pressure regulator is vacuum controlled to produce 2.5 bar (2.5 X barometric pressure or 2.5 atmospheres' pressure) when vacuum is low (pulling) and 2 bar at high vacuum (cruising & no - load.) After the pressure regulator, the fuel just returns to the tank. That does not need to be in the bottom, but I'd feel a lot safer with it returning underneath the gasoline in the tank, as if it is released into the airspace at the top of the tank, there will be a lot of vapor produced and a high hazard of explosion. Even if it enters tha tank high, it should have a tube extending to the bottom. (Consider that your sending unit has exposed windings and potential as an ignition source if sufficient oxygen and fuel atomization exists!)

You'll probably not use an EGR or a deceleration valve (anti-backfire valve - I hate 'em cuz they slow deceleration response.) The EGR's clog up - that might be a difficult thing to get a replacement for; hopefully you won't need it (legally.)

Have I forgotten anything? Fitting the pieces into the space will be your biggest problem as I see it.

L-Jetronic is as bulletproof as anything but is one of the most basic systems and whereas it offers good performance, it isn't anything close to newer systems. As Tim said, there are ways to tweak the mixture, ways to trick the ECU into thinking it's doing something it isn't, ways around the cold-start circuitry. I had my bus over 100mph many times with stock L-Jetronic FI and a few simple tricks. Mostly it just goes and goes and goes and never needs any attention except filter changes.

-- Dave "Busahaulic" Pearson Fall City, Washington Remove obvious from addy to e-mail

MN AirHead wrote in message news:3fa7f78d$0$103$ snipped-for-privacy@newsreader.goldengate.net...

computer, wires etc)?

picked it up for the

car... this one

Reply to
Busahaulic

Hi.Dave.Wow!Lots of information.Are there any manuals you would recomend before I waste any more time on alternatives The VW systems always worked fine when new.Can never get them working right on oldies.The information that there are sources for recycled parts is news to me.Great.Luddite Steve

Reply to
Ilambert

Bentley has a Bosch Fuel Injection manual. Get it and read the entire book then go back and read the stuff pertaining to the L-Jetronic. You'll then be as much of a pro as anyone! (Just lacking experience!) I was not aware there were any problems getting parts. As they became unavailble through VW, the Brazilian parts became available aftermarket. The only item subject to wear (besides the TB) is the airflow meter and I KNOW those are available remanned. Once you read the book, you'll be able to figure out how you can build an air bypass for fast idle that is manually controlled and they tell you how to adjust mixture. I had a better system and you're welcome to e-mail me for more details. I ran a wire to the dash from the coldstart injector to a momentary switch for cold start and for acceleration / high speed.

would recomend

systems always worked

oldies.The information

me.Great.Luddite Steve

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Reply to
Busahaulic

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