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Tram
Samba Socialist
Joined: May 02, 2003
Posts: 22729
Location: Still Feelin' the Bern- Once you've felt it you can't un- feel it.
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 Posted: Thu Mar 21, 2024 9:28 pm Post subject: Re: ECU fuel pump bypass |
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| jessehattabaugh wrote: |
| Tram wrote: |
| That's more and more of a common issue these days. |
I've seen a few other mentions of it. I wonder if there's any information about which transistors I need to check, and what kind to replace with. |
You could always just gently open the box and see what fried. Sometimes it's as simple as re-flowing a solder joint. Sent you a PM back.
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| Bryan67 wrote: |
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jessehattabaugh
Samba Member
Joined: July 10, 2023
Posts: 4
Location: Pacific Northwest
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| Posted: Thu Mar 21, 2024 9:02 pm Post subject: Re: ECU fuel pump bypass |
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| Tram wrote: |
| That's more and more of a common issue these days. |
I've seen a few other mentions of it. I wonder if there's any information about which transistors I need to check, and what kind to replace with. |
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Tram
Samba Socialist
Joined: May 02, 2003
Posts: 22729
Location: Still Feelin' the Bern- Once you've felt it you can't un- feel it.
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| Posted: Wed Mar 20, 2024 7:23 pm Post subject: Re: ECU fuel pump bypass |
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| jessehattabaugh wrote: |
I'm trying to get a 1970 Squareback running, and I've determined that the ECU is not sending ground to the fuel pump relay when the key is turned on. I tested the #19 wire directly at the ECU. It is sending 8v positive instead. The original owners had bypassed the fuel pump relay with a wire directly from the fuseblock to the pump.
Should I:
1) buy a replacement ECU
2) open it up and test the components and solder on replacements
3) just leave the fuel pump relay bypass in place and see if the rest of the ECU still works |
That's more and more of a common issue these days. Ground the pump relay wire to the body and see if she fires up.
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| Bryan67 wrote: |
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jessehattabaugh
Samba Member
Joined: July 10, 2023
Posts: 4
Location: Pacific Northwest
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| Posted: Wed Mar 20, 2024 4:40 pm Post subject: ECU fuel pump bypass |
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I'm trying to get a 1970 Squareback running, and I've determined that the ECU is not sending ground to the fuel pump relay when the key is turned on. I tested the #19 wire directly at the ECU. It is sending 8v positive instead. The original owners had bypassed the fuel pump relay with a wire directly from the fuseblock to the pump.
Should I:
1) buy a replacement ECU
2) open it up and test the components and solder on replacements
3) just leave the fuel pump relay bypass in place and see if the rest of the ECU still works |
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MARTYB
Samba Member
Joined: March 26, 2023
Posts: 8
Location: AUSTRALIA
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| Posted: Tue Feb 13, 2024 2:30 pm Post subject: Re: Fuel injection relief here! |
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| Thanks to the members for the info provided |
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FastyOrange
Samba Member
Joined: November 15, 2012
Posts: 111
Location: Greenville, SC
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| Posted: Sun Feb 11, 2024 9:24 pm Post subject: Re: Fuel injection relief here! |
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That single wire on your mps is a ground. The other end is either all by itself at the engine case center line or with the other grounds at the base of the oil breather (I can't remember which off of the top of my head).
Jon
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72 FI Fastback
70 FI Fastback (Parts Car) |
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KTPhil 
Samba Member
Joined: April 06, 2006
Posts: 34023
Location: Conejo Valley, CA
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| Posted: Sun Feb 11, 2024 6:49 pm Post subject: Re: Fuel injection relief here! |
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A photo would help a lot. MPS part number as well.
VW did add some ground wires in later FI cars. |
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MARTYB
Samba Member
Joined: March 26, 2023
Posts: 8
Location: AUSTRALIA
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| Posted: Sun Feb 11, 2024 3:39 pm Post subject: MPS Wiring Question |
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Hello Members
I own a 1972 Fastback TLE with the original fuel injection system.
The MPS fitted on my car has an additional wire connected to a single male terminal at the rear of this part and it then goes into the fuel injection wiring harness.
Is this an earth or ground wire ?
I have a better condition spare FI wiring harness i would like to install , however it is not fitted with this wire mentioned above
Thanks for any help provided |
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jasle
Samba Member
Joined: July 08, 2008
Posts: 149
Location: Austin Texas
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| Posted: Fri Sep 29, 2023 3:15 pm Post subject: Re: Fuel injection relief here! |
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| KTPhil wrote: |
| jasle wrote: |
| KTPhil wrote: |
| It is a white wire, and that T1 connector is in the engine bay, left side, forward of the left intake tubes. |
Thx. Found it. Someone spliced in a blue wire. That fixed the fuel pump not coming on. Starts, runs fairly well with 2 caveats.
Lopes like cammed when cold
Super rich. Black soot on bumper and black smoke. |
Vacuum leaks often cause these symptoms.
Check hose from plenum (IAD) to pressure sensor (MPS, under left side of engine bay floor).
Then a systematic check of all hoses for vacuum leaks. |
Yup, that was it. Many Thanks!
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Jason in Austin Texas
69 Notch Auto FI
Seagul Blue |
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KTPhil
Samba Member
Joined: April 06, 2006
Posts: 34023
Location: Conejo Valley, CA
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| Posted: Fri Sep 29, 2023 2:27 pm Post subject: Re: Fuel injection relief here! |
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| jasle wrote: |
| KTPhil wrote: |
| It is a white wire, and that T1 connector is in the engine bay, left side, forward of the left intake tubes. |
Thx. Found it. Someone spliced in a blue wire. That fixed the fuel pump not coming on. Starts, runs fairly well with 2 caveats.
Lopes like cammed when cold
Super rich. Black soot on bumper and black smoke. |
Vacuum leaks often cause these symptoms.
Check hose from plenum (IAD) to pressure sensor (MPS, under left side of engine bay floor).
Then a systematic check of all hoses for vacuum leaks. |
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jasle
Samba Member
Joined: July 08, 2008
Posts: 149
Location: Austin Texas
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| Posted: Fri Sep 29, 2023 2:21 pm Post subject: Re: Fuel injection relief here! |
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| KTPhil wrote: |
| It is a white wire, and that T1 connector is in the engine bay, left side, forward of the left intake tubes. |
Thx. Found it. Someone spliced in a blue wire. That fixed the fuel pump not coming on. Starts, runs fairly well with 2 caveats.
Lopes like cammed when cold
Super rich. Black soot on bumper and black smoke.
_________________
Jason in Austin Texas
69 Notch Auto FI
Seagul Blue |
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jasle
Samba Member
Joined: July 08, 2008
Posts: 149
Location: Austin Texas
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| Posted: Fri Sep 29, 2023 2:18 pm Post subject: Re: Fuel injection relief here! |
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| KTPhil wrote: |
| It is a white wire, and that T1 connector is in the engine bay, left side, forward of the left intake tubes. |
Thx. Found it. Someone spliced in a blue wire. That fixed the fuel pump not coming on. Starts, runs fairly well with 2 caveats.
Lopes like cammed when cold
Super rich. Black soot on bumper and black smoke.
_________________
Jason in Austin Texas
69 Notch Auto FI
Seagul Blue |
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KTPhil
Samba Member
Joined: April 06, 2006
Posts: 34023
Location: Conejo Valley, CA
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| Posted: Fri Sep 29, 2023 2:13 pm Post subject: Re: Fuel injection relief here! |
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It is a white wire, and that T1 connector is in the engine bay, left side, forward of the left intake tubes.
This is an aftermarket crimp on connector, but the clear plastic VW connector goes here also.
Last edited by KTPhil on Fri Sep 29, 2023 2:19 pm; edited 1 time in total |
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jasle
Samba Member
Joined: July 08, 2008
Posts: 149
Location: Austin Texas
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| Posted: Fri Sep 29, 2023 1:19 pm Post subject: Re: Fuel injection relief here! |
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Wondering if anyone knows the color of the wire 19 to connection 85 on the pump relay? I'm currently missing this wire. Have a few wires under the dash disconnected. Looks like a ground from ECU
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Jason in Austin Texas
69 Notch Auto FI
Seagul Blue |
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rosevillain
Samba Member
Joined: December 28, 2005
Posts: 1290
Location: roseville, ca
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| Posted: Mon Sep 11, 2023 8:14 pm Post subject: Re: Fuel injection relief here! |
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| Been a while. If I unplug the temp sensor at the AAR, the car seems (haven't driven it, only vroomvroom noises in the driveway) to run well. Connected, the car doesn't respond well to idle adjustments, and doesn't rev. Fuel pressure is set to 28psi and timing is at 5BTDC. Of course I haven't ohmed it. Time to source one? '68 manual |
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MVB
Samba Member
Joined: June 21, 2023
Posts: 58
Location: Sydney, Australia
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| Posted: Sat Jul 22, 2023 6:05 am Post subject: Re: Fuel injection relief here! |
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| Actually they’re aerobatic compatible so with the right manifolding one could have one on its side. Meaning one can do it with just one afterall |
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MVB
Samba Member
Joined: June 21, 2023
Posts: 58
Location: Sydney, Australia
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| Posted: Tue Jul 11, 2023 10:08 am Post subject: Re: Fuel injection relief here! |
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Thanks for the reply Tram
At it guess, packaging wise, it seems one would have to use 2. I s’pose one just halves the mixture settings & double the thickness of the return cable springs on the throttle slide controls & do equivalent regards the on the fly mixture controls.
This is the one listed for VWs:-
https://www.rotecaerosport.com/tbi-34-2
I’ve been told that to dial the mixture settings well, a vacume gauge or manifold pressure gauge would help. Are they just 2 different names for the same gauge?
Rotec also market an “air fuel ratio kit with a wide band Oxygen sensor” for use with the TPI.
Obligatory linkage:-
https://store.rotecaerosport.com/air-fuel-ratio-kit |
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Tram
Samba Socialist
Joined: May 02, 2003
Posts: 22729
Location: Still Feelin' the Bern- Once you've felt it you can't un- feel it.
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| Posted: Mon Jul 10, 2023 11:29 pm Post subject: Re: Fuel injection relief here! |
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Problem on a Type 3 would be getting it to fit under the deck. Do they make a twin setup low enough for this?
Stock FI tops out at 1776. Even then you need the blue injectors from a Mercedes 4,5 rather than the stock yellow ones. But beyond that displacement the air intake system will choke it.
If you're sick of the petrol bills your best bet is a stock 1600 either carbed or injected. Sorry.
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Немає виправдання для війни! Я з Україною.
| Bryan67 wrote: |
| Just my hands. And a little lube. No tools. |
To best contact me, please use the EMAIL function in my profile |
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MVB
Samba Member
Joined: June 21, 2023
Posts: 58
Location: Sydney, Australia
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| Posted: Sun Jul 09, 2023 11:33 am Post subject: Re: Fuel injection relief here! |
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Would the simplest way to convert to fuel injection from carbies, to go for one of those slide throttle TBI setups from Rotec? They are very simple with just an idle setting that can be locked down & on the fly throttle & mixture by either Bowden cable or rods.
https://www.youtube.com/watch?v=c9PyeXttRQs
They do make a model for VWs
I have a Stan Pobjoy Racing 1916 with twin dyno jetted Solexes & I’m getting sick of the petrol bills |
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Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 22438
Location: Kimball, Mi
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| Posted: Thu Jul 06, 2023 12:23 pm Post subject: Re: Fuel injection relief here! |
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First- please replace ALL rubber fuel lines, even the short ones on the injectors. GENTLY cut the ferrules to do this and use correct injector clamps. You don't want a fire.
To use the Airtex 2000 merely block off the return nipple that went to the 3 nipple Bosch pump. No other mods required.[/quote]
Yup, you'll need 20 feet of 5/16ths fuel hose and 34 FI hose clamps to do the job. Also do it with the fuel empty, so you're not taking a gas bath. I hope this helps.
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Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
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| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
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