Author |
Message |
tbednar Samba Member
Joined: April 01, 2004 Posts: 7
|
Posted: Fri Apr 02, 2004 11:51 am Post subject: ripping out fuel injection for weber carb |
|
|
Hi Guys,
I have a 79 SB and am having problems with my computer...I think. The thing is just not firing. I want to switch it out with a weber carb. I was wondering how the performance and mileage will be affected? Also, I have a dual port manifold kit, but I see that I am going to need an alternator stand/oil fill, is there anything else I will need? What will I have to take care of for the electronics beside ripping it out?
Thanks for the help!
Tim Bednar
[email protected] |
|
Back to top |
|
|
jhicken Samba Member
Joined: October 24, 2003 Posts: 9466 Location: Fallbrook, CA
|
Posted: Fri Apr 02, 2004 12:11 pm Post subject: |
|
|
Your mileage will suffer with the Webber. Consider finding a good mechanic that knows fuel injection [it doesn't have to be a VW mechanic]. Something as simple as a small crack in the rubber intake boot can make the car run rough or not at all.
I've put over 200,000 miles on my '79 without any serious problem. Over the last twenty years I replaced two leaky injectors, and the intake boot a couple of times. That's it. When properly maintained the FI runs great. My car can sit for three months and will fire on the the third crank. The only extra thing I've done is drop a pint of injector cleaner in the gas tank once every 6000 miles [every other oil change].
jeffrey |
|
Back to top |
|
|
sixfootdan Samba Smartass
Joined: February 13, 2002 Posts: 4848 Location: \Lo*ca"tion\, n. 1. The act or process of locating.
|
Posted: Fri Apr 02, 2004 2:11 pm Post subject: |
|
|
You will need an electric fuel pump. If you do convert it, I would use a stock carb instead of that single weber crap. IMO _________________ Schrodinger's cat walked into a bar and it didn't.
GO SEAHAWKS!!! |
|
Back to top |
|
|
70 140 Samba Member
Joined: September 22, 2002 Posts: 8471 Location: Ontario Canada
|
Posted: Fri Apr 02, 2004 3:30 pm Post subject: |
|
|
MEANIRISHMOFO wrote: |
You will need an electric fuel pump. If you do convert it, I would use a stock carb instead of that single weber crap. IMO |
agreed, skip the weber progressive crap and get a good 34/3 or a 30/1 |
|
Back to top |
|
|
dstefun Samba Member
Joined: February 20, 2002 Posts: 3338 Location: Sacratomato
|
Posted: Sat Apr 03, 2004 1:23 am Post subject: |
|
|
Tim - welcome to TheSamba! I agree with jhicken - leave it there and get it fixed and you'll be far happier with performance and gas mileage.
But if you're dead set on replacing it, be sure to save everything you take off because for every one taken off there are at least 2 other 79 owners out there looking for FI systems to put back on! Especially when you go to sell the car. In CA we couldn't take it off if we wanted to because it has to be OG to pass smog until it's 30 years old. |
|
Back to top |
|
|
asnowsquall Samba Member
Joined: March 23, 2004 Posts: 136 Location: Vermont
|
Posted: Sat Apr 03, 2004 1:45 pm Post subject: |
|
|
Why do you think it's the computer? They are pretty hearty devices. My car was running OK, but I replaced one injector which was actually the wrong one. In the process of working on the car and having the air cleaner out I'm bumping the hoses which are ready to crumble. When I got done, the car would start and stall. Turns out that the crank case breathing hose which plugs into the boot between the Mass Flow Sensor and the throttle valve had pulled out. I got it back in and it still wouldn't start properly. I finally got it in a postion that worked OK, but then found out later that the hose had all kinds of dry rot and leaks. Replaced hose, fixed. These kind of air leaks can cause the car to run lean, which you never want on the Air Cooled motor. If your not looking to make the thing fast, stick with the F.I. its really nice, and not to hard to understand when you learn it. Also, get the Bentley manual!!! And also make sure the ignition is working properly, its what the Computer uses to time the fuel pulses. _________________ Dave
1968 Beetle
1978 Super Beetle Convertible
1997 GMC Suburban 6.5 Diesel running WVO
2003 Honda Odyssey |
|
Back to top |
|
|
tbednar Samba Member
Joined: April 01, 2004 Posts: 7
|
Posted: Sat Apr 03, 2004 8:06 pm Post subject: man, I thought I was on the right track... |
|
|
Okay Guys, I get the hint! I will check all of my hoses and seals where there could be a vacuum leak. And Crap! I bought a weber progressive two barrel to replace the FI.
I had a guy that is an airplane mechanic/volkswagon afficinado work on the car. I sent it to him for a tune up. When it comes back he says that it quits running intermittenly. Will run sometimes and die, or not start again. He cannot find an answer to it at first and then said he thought it was the computer.
Thanks for the info guys. I am interested in any other conspiracy theories.
Tim[/code] |
|
Back to top |
|
|
keifernet Samba Search & Rescue
Joined: May 11, 2002 Posts: 19395 Location: Samba Center for Behavioral Science
|
Posted: Sat Apr 03, 2004 9:51 pm Post subject: |
|
|
While I agree the stock FI set-up is great if it is saveable, at some point ( and especially since none of us are there to see the condition ourselves) one must consider that the old wiring harness, and the rest of the system may well be in such a bad state that converting to carb is the most economical and practical for the owner.
If that is the case then carry on, and IMO and experience the Weber is not such a bad carb, if you are starting with a new one out of the box.
But that said....The biggest hurdle you have is that the stock FI heater boxes and exhaust do not have the provision for the heat riser tubes to be connected to the intake manifold and a single carb set up ( stock or weber progressive) really needs the pre-heat from the heat risers to run well...
You may end up having to change to 74 and earlier heater boxes and a header system to get rid of the FI exhaust.
Since this is even more $$$ you may want to investigate what it will take to save the FI and weigh your options carefully |
|
Back to top |
|
|
dstefun Samba Member
Joined: February 20, 2002 Posts: 3338 Location: Sacratomato
|
Posted: Sat Apr 03, 2004 10:41 pm Post subject: |
|
|
Tim - if you want to try to fix it, there is some help available. It really is a good system when it's working right. Similar Bosch systems were used on almost all Europeon late 70's and early 80's cars (even Datsun used a clone of it under license from Bosch on the early 80's 280ZX) so you should be able to find somebody wherever you are that is familiar with the system.
Here's a prior thread with some links to manuals and other info....be sure to check out the '79 conv. site listed - sweet car.
http://www.thesamba.com/vw/forum/viewtopic.php?t=61027
and here's another site related to
Bosch L-jetronic Fuel Injection Troubleshooting, Maintenance & Repair
http://www.seattlex19.org/data/figuide/
And note my comment on the other thread about clamping the hoses - sometimes thats all they need. But I have seldom seen a bad computer. Bad connections, yes. Good luck! |
|
Back to top |
|
|
79SuperVert Samba Member
Joined: May 31, 2002 Posts: 9758 Location: Elizabeth, NJ & La Isla Del Encanto
|
Posted: Mon Apr 05, 2004 7:50 am Post subject: |
|
|
Hey, thanks for the Bosch manual link!! Although similar info is in the Bentley manual it's nice to have the original literature. |
|
Back to top |
|
|
VW BRETT Samba Member
Joined: May 11, 2001 Posts: 278
|
Posted: Mon Apr 05, 2004 5:34 pm Post subject: |
|
|
Find the problem and keep the fuel injection, Thought I had a problem with mine once and it turned out to be a spark plug wire resistor, it was working intermitantly. I have the Bosch book and it is very detailed. _________________ YOU CAME IN THAT THING? YOU'RE BRAVER THAN I THOUGHT.
63 SINGLECAB
67 13 WINDOW DELUX
20 ATLAS |
|
Back to top |
|
|
tbednar Samba Member
Joined: April 01, 2004 Posts: 7
|
Posted: Sat Apr 10, 2004 9:48 am Post subject: OKAY, I gotta hand it to you guys! |
|
|
Thanks for all the advice, and the manuals are great. I found four vacuum leaks and one hose missing. I cleaned them up, inspected them and re-attached them. The thing is running again! Now I have to re-adjust the idle...it is way too fast, probably because he was adjusting it with vacuum leaks. I also seem to have limited maximum power. I will be reading and get out the ohm meter that's for sure.
thanks again
Tim
79 vert
98 mroadster
93 f150 |
|
Back to top |
|
|
asnowsquall Samba Member
Joined: March 23, 2004 Posts: 136 Location: Vermont
|
Posted: Sun Apr 11, 2004 3:14 am Post subject: |
|
|
Excellent job! I wonder where the timing is at? The idle is a funny thing. My first manual was a Haynes and it says to adjust the idle with the screw on the throttle arm, the one that actually stops it. So I was adjusting it there. Then I get the Bently Manual and it says don't adjust it there, use the air flow screw on the front face of the throttle body. I tried adjusting it and sure enough it changes the idle. Then I remembered my 1975 914 had the same system and all it had was the air flow screw, so I'll be using this from now on. Think I'll lean toward the Bently Manual also! _________________ Dave
1968 Beetle
1978 Super Beetle Convertible
1997 GMC Suburban 6.5 Diesel running WVO
2003 Honda Odyssey |
|
Back to top |
|
|
tbednar Samba Member
Joined: April 01, 2004 Posts: 7
|
Posted: Mon Apr 12, 2004 9:45 am Post subject: manual schmanual |
|
|
I will definately try the bently manual for the idle adjustment. I have three manuals and they all have different timing information in them for the fuel injected engine. It has been a very confusing journey. Thanks guys for the ongoing support.
Tim |
|
Back to top |
|
|
|