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RidinRetro1973 Samba Member
Joined: April 10, 2007 Posts: 599 Location: Chicago
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Posted: Thu Aug 25, 2016 7:40 pm Post subject: '79 Fuel Injection Poor Performance Over 60mph |
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I mostly post on the 68+ Beetle forums, but I've been lurking on this forum for a long time. I'm looking for some thoughts on my Bus.
The motor has been rebuilt twice in the last 2 years by a reputable local VW shop. Its currently in the shop and the owner who has done most of the work can't figure it out.
Its a '79 Westy with FI. It came out from its 15 year slumber in 2005. When we got it, a lot of the typical maintenance was performed on it by my dad. It ran great, and when things broke, they were replaced and fixed. I had no problem taking it on long trips. I drove it yearly from Chicago to Buses Nowhere near the arch, and took it out to Colorado, and to Chattanooga. It was the most reliable air cooled in our fleet of 4 aircooleds. It had no problem cruising at 70mph(and was strong at speeds greater). In the Rockies and the Smoky's it pulled hard up the hills.
The Bus went into the shop 3 years ago for poor performance, and inability to go faster than 40mph with severe bucking and chattering hydro lifters. At this time it was decided the motor needed a rebuild in hopes of solving the problem.
It came back from the shop with the motor rebuilt and I left the shop headed to a camping event. The Bus died 2.5 hours into the trip with the same problem as before the rebuild. The lifters wouldn't pump up, and the Bus bucked and couldn't keep up with traffic. It ran great at 70mph earlier in the day when I left. It was towed back to the shop.
The motor was torn down again and new hydro lifters were installed last year. I got it back, and the same thing happened, the lifters wouldn't pump up and seized so back to the shop it went.
Last winter the motor was torn into again, and the hydro lifters were swapped out for solids. I got the Bus back early summer and drove it a few hundred miles before the same problem came back. I did a bunch of reading on here as well as itinerant air cooled. At the time I was having problems I realized Colin had just been through my area two weeks prior.
I dug into it a bit myself. The AFM in the Bus was a python rebuild. The original AFM was replaced because the circuit board was worn. I tried putting the OG AFM back in to see if the Bus ran differently. To my surprise it ran great with the OG AFM back in. It had issues with jumpy acceleration because of the worn circuit board. I drove it for a few days like that until it started acting up during some rain. It bucked, had no power over 40mph.
Its gone through 2 sets of new injectors. Shop owner said he unplugged injector #3 and the Bus doesn't run any different. Injector #1 failed last year. Thinks injector 3 is firing too late. Timing is dead on.
New temp sensor 2
AFM rebuilt and calibrated
Double Relay was changed at some point during the past few years
New plugs gapped correctly
Valves gapped correctly
New distributor cap & rotor
Points were replaced with pertronix, no change
All vacuum hoses were checked and replaced
S-boot checked for cracks
Distributor taken apart and rebuilt
Coil replaced a few years back
New fuel pump/filter
Engine wiring harness swapped out with another
ECU swapped with a good working unit
I might be forgetting some of the work thats been done to it at the moment. The shop has covered the cost of everything post-rebuild. At this point the idea of ditching the FI in favor of carbs has been thrown around a few times. Its been over 3 years and I've put less than 500 miles on my Bus and I'm looking for any sort of guidance or ideas to pass along to try and get my Westy back on the road.
Thanks!
_________________ Instagram - VÄÄN Design Co.
My builds:
'68 AutoStick "Gawaine the Green Knight"
Modern Vanagon Westy Interior |
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aerosurfer Samba Member
Joined: March 25, 2012 Posts: 1602 Location: Indianapolis, IN
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Posted: Thu Aug 25, 2016 8:08 pm Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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Are you doing any of the work yourself or with the shop, or just relaying what they told you?
Don't ditch the FI for carbs, just don't. Besides if you keep thinking (or actually being) lifters carbs won't fix anything.
The AFC manual is pretty comprehensive in its testing of FI components. Good for you to have, and I would expect your shop to already have.
http://www.thesamba.com/vw/archives/manuals/afc_fi...Manual.pdf
Injectors all fire at the same time. You don't mention the series resistor being replaced or checked. That could lead to intermittent performance at the injector if a wire was cracked, see my thread about series resistor repair;
http://www.thesamba.com/vw/forum/viewtopic.php?t=660153&highlight=
Also I'm assuming you have a '79 federal, not a Cali emission bus with the oxygen sensor and different distributor?
What was rebuilt twice in the last few years? Engine torn down to the bearings? New heads? Valve train work? Your description is good and thorough, and it sounds like your shop is standing by their work to make it right. Hopefully it's a relatively simple electrical or component related issue. _________________ Rebuild your own FI Harness..My Harness
77 Westy 2.0L Rockin and Rolling Resto!
72 Sportsmobile (sold)
79 Tran$porter... Parts car money machine (gone) |
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WendyArmbuster Samba Member
Joined: March 03, 2006 Posts: 330 Location: Springfield, MO
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Posted: Thu Aug 25, 2016 8:15 pm Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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I think all of the injectors fire at the same time. It's not sequential. _________________ Brian Z
1978 Westfalia |
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aeromech Samba Member
Joined: January 24, 2006 Posts: 16954 Location: San Diego, California
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Posted: Thu Aug 25, 2016 8:26 pm Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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Yeah, pretty much what he said. In addition, hydraulic lifters and solid lifters use different cam shafts so was the case split each time? Also, I'm thinking that the original engine problem might have been something with the FI system. Then after rebuild you just put the bad parts back on and experienced the same issue again. You need to find a mechanic that can actually troubleshoot. Not one that just throws parts at it. As was said, there's a manual available for free online that fully describes the troubleshooting for every FI component using simple multimeters, etc. It's sad to say but I think you've been throwing hundred dollar bills away by not finding a mechanic that knows more than just how to read a diagnostic code on an OBD2 scanner _________________ Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound |
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RidinRetro1973 Samba Member
Joined: April 10, 2007 Posts: 599 Location: Chicago
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Posted: Thu Aug 25, 2016 8:37 pm Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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Thanks for the replies and suggestions so far.
I should have mentioned that the shop is a restoration and service shop that specializes in aircooleds. The owner has a lot of experience with fuel injection, but I think is more knowledgable with type 1 motors.
My dad and I have done some of the work ourselves. At this point, the Bus is at the shop, and I'm in contact with the owner daily about what is being done.
Not sure if he has the AFC manual, but I will send it along to him. Appreciate it. I have the fuel injection troubleshooting book(yellow&blue). I also sent along the series resistor information.
It is Federal, originally bought in Florida.
Cam and pushrods were changed when the lifters were changed.
He did mention that the Bus idles great, its only under load that it stumbles and lacks power. Early in the summer when I initially got it back it seemed like it ran great when on flat ground or with a tail wind, but had problems with a head wind and climbing even small grades. _________________ Instagram - VÄÄN Design Co.
My builds:
'68 AutoStick "Gawaine the Green Knight"
Modern Vanagon Westy Interior
Last edited by RidinRetro1973 on Thu Aug 25, 2016 8:43 pm; edited 1 time in total |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50334
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Posted: Thu Aug 25, 2016 8:41 pm Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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I am going to guess that the fuel tank ventilation system is clogged. It could also be something floating around in the tank that randomly blocks the outlet. |
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aerosurfer Samba Member
Joined: March 25, 2012 Posts: 1602 Location: Indianapolis, IN
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Posted: Thu Aug 25, 2016 8:43 pm Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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Was the fuel tank serviced? Could be a blockage from rust or long term debris that chokes out when higher volume is being demanded. Or if your vapor lines are plugged and the tank is pressurizing. _________________ Rebuild your own FI Harness..My Harness
77 Westy 2.0L Rockin and Rolling Resto!
72 Sportsmobile (sold)
79 Tran$porter... Parts car money machine (gone) |
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aerosurfer Samba Member
Joined: March 25, 2012 Posts: 1602 Location: Indianapolis, IN
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Posted: Thu Aug 25, 2016 8:43 pm Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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Wildthings wrote: |
I am going to guess that the fuel tank ventilation system is clogged. It could also be something floating around in the tank that randomly blocks the outlet. |
Damn you beat me to it _________________ Rebuild your own FI Harness..My Harness
77 Westy 2.0L Rockin and Rolling Resto!
72 Sportsmobile (sold)
79 Tran$porter... Parts car money machine (gone) |
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aeromech Samba Member
Joined: January 24, 2006 Posts: 16954 Location: San Diego, California
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Posted: Thu Aug 25, 2016 8:46 pm Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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Yeah, it could be something dumb like a rag in the tank. It could also be that it's either running too rich or too lean. Has anyone checked? _________________ Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound |
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RidinRetro1973 Samba Member
Joined: April 10, 2007 Posts: 599 Location: Chicago
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Posted: Thu Aug 25, 2016 8:49 pm Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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aeromech wrote: |
Yeah, it could be something dumb like a rag in the tank. It could also be that it's either running too rich or too lean. Has anyone checked? |
Yes, mixture has been checked with an exhaust gas analyzer. Turning the mixture screw rich or lean doesn't change how it acts.
Fuel tank was cleaned after the first breakdown as bad gas was suspect.
Really appreciate all the help so far! _________________ Instagram - VÄÄN Design Co.
My builds:
'68 AutoStick "Gawaine the Green Knight"
Modern Vanagon Westy Interior |
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RidinRetro1973 Samba Member
Joined: April 10, 2007 Posts: 599 Location: Chicago
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Posted: Thu Aug 25, 2016 8:59 pm Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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aerosurfer wrote: |
Was the fuel tank serviced? Could be a blockage from rust or long term debris that chokes out when higher volume is being demanded. Or if your vapor lines are plugged and the tank is pressurizing. |
Would test driving without the gas cap test if the vapor lines are clogged? _________________ Instagram - VÄÄN Design Co.
My builds:
'68 AutoStick "Gawaine the Green Knight"
Modern Vanagon Westy Interior |
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aeromech Samba Member
Joined: January 24, 2006 Posts: 16954 Location: San Diego, California
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Posted: Thu Aug 25, 2016 9:03 pm Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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Yes _________________ Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound |
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RidinRetro1973 Samba Member
Joined: April 10, 2007 Posts: 599 Location: Chicago
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aeromech Samba Member
Joined: January 24, 2006 Posts: 16954 Location: San Diego, California
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Posted: Thu Aug 25, 2016 9:15 pm Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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Many times I've found the real reason something doesn't work is because of something stupid. Like in my Volvo when the battery died. I thought it had to be the alternator. Then I thought it had to be the voltage regulator. All difficult and expensive to fix. Finally after many attempts to find the cause I realized that I had the wrong fan belt. It felt tight but didn't have the correct profile to fit the groove so at night with a heavy load on the electrical system the belt would slip and then the battery would die. You have to keep going back and analyzing what you've done _________________ Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound |
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RidinRetro1973 Samba Member
Joined: April 10, 2007 Posts: 599 Location: Chicago
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Posted: Thu Aug 25, 2016 9:25 pm Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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aeromech wrote: |
Many times I've found the real reason something doesn't work is because of something stupid. Like in my Volvo when the battery died. I thought it had to be the alternator. Then I thought it had to be the voltage regulator. All difficult and expensive to fix. Finally after many attempts to find the cause I realized that I had the wrong fan belt. It felt tight but didn't have the correct profile to fit the groove so at night with a heavy load on the electrical system the belt would slip and then the battery would die. You have to keep going back and analyzing what you've done |
I hate when that happens. When I first started driving my '68 Autostick I had problems with it not wanting to go into gear. Being my first autostick I didn't completely understand how the system worked. I tried adjusting the shifter, checked the coupler, and made sure the vacuum lines were good, only to find the wire that comes out of the shifter and activates the servo was frayed and grounding out on the tunnel. 1" of electrical tape later and its been shifting perfect since. Spent all day trying to figure that one out. _________________ Instagram - VÄÄN Design Co.
My builds:
'68 AutoStick "Gawaine the Green Knight"
Modern Vanagon Westy Interior |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Thu Aug 25, 2016 11:17 pm Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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Get ahold of Asiab3 http://www.thesamba.com/vw/forum/profile.php?mode=viewprofile&u=290054 while he is in Michigan headed east and see what he charges to take a look at it. He knows enough about late bays to maybe resolve the issue. There is a lot that could be going on and maybe Robbie can help you resolve it, If not hire Colin (amskeptic) next time he is passing thru your area.
If you do not have experience working with Fuel injection there is a learning curve. We can help you but the results will not be instantaneous. As an example: since all 4 injectors fire together on the same wire that is tied together at the ECU there is no way "Thinks injector 3 is firing too late" can happen. That statement is instant proof the shop does not understand your fuel injection. That statement is equal to a farmer saying the chicken isn't laying eggs, and the corn won't grow this year because the sow didn't have eight piglets. It is proof of total ignorance on the system. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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Hoody Samba Member
Joined: November 28, 2007 Posts: 1948
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Posted: Fri Aug 26, 2016 12:13 am Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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When you said the FI harness was swapped out, did you put a brand new one from Kyle in? If you just swapped it out for another 37 year old one then that may be a big part of the problem. Most of these harnesses are pretty toasted at this age. You could be chasing your tail forever. Another issue may be the rebuilt AFM. The fact that it ran better with the old AFM tells me that the rebuild was garbage. I am not an LJet expert. But I am fairly certain that the circuit board in these that gets worn have not been produced for a long time. So the phrase rebuild does not really apply. A friend of mine went through about 6 rebuilt ones before he gave up on them and found an NOS one. But that is not always an option. If your going to keep the Bus and love it I would invest in a new wiring harness from Kyle. It's money well spent. I may be able to find you a NOS AFM. They are becoming extremely hard to find. But I may get lucky. PM me the part number your looking for. Did you check the numbers on the rebuilt AFM versus the original? Because a 79 Cali AFM is different than a 79 Federal if I am not mistaken. So send me the number for the AFM thatwas was in the Bus when it ran well. I would have the injectors sent to Witch hunter or Cruzin performance. I would also look at the FPR before anything else. I am surprised your mechanic never mentioned replacing this. There is a port on the left side fuel rail that you can put a gauge on to test this. I would do that after you check your fuel filter for rust etc. the FPR can be had relatively inexpensivly. Start with the less expensive parts first. Also down load the LJet guide which I believe in in the archives. All of the individual components should be tested. If your fuel filter isn't clogged. My money is on the FPR. But after the car gets hot your harness may have issues and the AFM may have issues. Also check the numbers on your ECU. If you have an incorrect ECU or AFM or vise versa that will eff things up. The 79 Cali set up was a PITA! |
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Silverboot Samba Member
Joined: July 19, 2014 Posts: 108 Location: Las Vegas
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Posted: Fri Aug 26, 2016 12:47 am Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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Quote: |
Get ahold of Asiab3 http://www.thesamba.com/vw/forum/profile.php?mode=viewprofile&u=290054 while he is in Michigan headed east and see what he charges to take a look at it. He knows enough about late bays to maybe resolve the issue. There is a lot that could be going on and maybe Robbie can help you resolve it, If not hire Colin (amskeptic) next time he is passing thru your area. |
I don't have anything to add from a troubleshooting point of view, but it may be worth it at this point just to get a different set of eyes on it. It sounds like you and the shop may just be too close to the project at this point, try to have Asiab3 or Colin or another shop try to diagnose, i would even contemplate omitting what's been done at this point just to get a completely fresh perspective. _________________ 79 FI CA Riviera
74 Smallframe Vespa |
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RidinRetro1973 Samba Member
Joined: April 10, 2007 Posts: 599 Location: Chicago
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Posted: Fri Aug 26, 2016 5:21 am Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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SGKent wrote: |
Get ahold of Asiab3 http://www.thesamba.com/vw/forum/profile.php?mode=viewprofile&u=290054 while he is in Michigan headed east and see what he charges to take a look at it. He knows enough about late bays to maybe resolve the issue. There is a lot that could be going on and maybe Robbie can help you resolve it, If not hire Colin (amskeptic) next time he is passing thru your area.
If you do not have experience working with Fuel injection there is a learning curve. We can help you but the results will not be instantaneous. As an example: since all 4 injectors fire together on the same wire that is tied together at the ECU there is no way "Thinks injector 3 is firing too late" can happen. That statement is instant proof the shop does not understand your fuel injection. That statement is equal to a farmer saying the chicken isn't laying eggs, and the corn won't grow this year because the sow didn't have eight piglets. It is proof of total ignorance on the system. |
Robbie got ahold of me through PM. I should say that he thought injector 3 might not be firing at all. _________________ Instagram - VÄÄN Design Co.
My builds:
'68 AutoStick "Gawaine the Green Knight"
Modern Vanagon Westy Interior |
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aerosurfer Samba Member
Joined: March 25, 2012 Posts: 1602 Location: Indianapolis, IN
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Posted: Fri Aug 26, 2016 5:44 am Post subject: Re: '79 Fuel Injection Poor Performance Over 60mph |
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Which should trouble shoot back to your series resistor first. Check for broken wires as well as continuity. If it's not firing it's likely to be a wiring problem, not the injector itself.
You said the injectors were replaced? Do you know what was put in there? Off the shelf China ones or old Bosch ones? Have you inspected the connection plugs at the injectors themselves.
I think a new set of eyes on the bus would be excellent too. Also simply just testing and assuring contact of each connection and ground would be a good start, as well as the condition of the harness plug at the ecu _________________ Rebuild your own FI Harness..My Harness
77 Westy 2.0L Rockin and Rolling Resto!
72 Sportsmobile (sold)
79 Tran$porter... Parts car money machine (gone) |
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