TheSamba.com :: View topic - New (sort of) T3 owner with some questions

Fri Jan 06, 2006 4:29 am

Hi all,

I'm new here, and was amazed when I found this site, with all of the info or resources available here. I have in the past had many VW's: type 1's, Sandrails, and a 69 Squareback (my favorite). I got away from VW's for a while, but recently bought a 72 Squareback for an extremely right price that I could not pass up.

I did a search on the site, but did not find an answer to my question.

My question is: Are there any issue's with jump starting a type 3 with a fuel injected engine? More specifically, is the ECU (brain box) sensative to a surge in voltage (as in hooking up jumper cables) or maybe a higher than normal voltage.

Is there a preferred procedure for jump starting a FI VW?

Any help would be appreciated, Glen

Fri Jan 06, 2006 5:56 am

Welcome back to the T3 clan

I had heard that jump-starting a FI car was bad for the ECU, but have been told by several here that it shouldn't affect the ECU at all....

Someone with actual experience should probably jump in here...

Fri Jan 06, 2006 7:16 am

I've also heard that it is not good for it, but I've done it before and haven't had any problems.

Fri Jan 06, 2006 5:51 pm

As long as you jump start is with another 12V car or charger, NO problems. Just like any car with electronics, If you hook up the cables backwards, you have a possibility of frying something.

Oh, welcome to the T-3 world.

Sat Jan 07, 2006 8:13 am

Thanks for the quick replies, I will be heading out in a couple of hours to see if I can get it going. Im thinking it might just be a loose cable or something easy to spot.

I can't wait to really start working on restoring/customizing my new toy!

Thanks again, Glen

Sat Jan 07, 2006 9:33 am

When you first turn the key on in a FI VW, you should hear 2 clicks and a whirr of the fuel pump in between. (about 1-2 seconds apart.) This is the fuel pump trying to prime the system. If you don't here these, there is no sense in cranking on the engine, as you dont have fuel pressure. It is possible that wome previous owner has hot wired the pump, but this is not safe. as the pump won't shut off automatically in an accident.
The pump is mounted under the gas tank on the right hand side.
If you find that you do have pressure, one of the first things to do on a older FI T3 is to replace all the fuel lines. They were known to deteriorate and leak, causing fires.
I have the FI troubleshooting manual on my web site.
http://classicvw.org/gallery/main.php?g2_view=core.ShowItem&g2_itemId=60

Sun Jan 08, 2006 8:18 am

Followup:

1) Found the + battery terminal some what corroded, cleaned it up, and the engine turns over fast, but will not start.

If found a wire, yellow w/red or pink tracer) that was not connected. it is under the rear seat near the battery. this wire has a 1/4" wide female slide-on terminal on it. I am not sure where it goes, it looks like it was long enough to reach the negative battery terminal, and there is an enpty male slide-on terminal where the negative battery cable bolts to the chassis but I am not sure. I do not want to burn up any electrical device

My electrical diagrams do not show this color wire anywhere?

2) In the engine compartment, there is another loose wire: green w/black ordk brown tracer, this wire has a very small (1/8" wide) female slide-on terminal on it. there is some kind of switch or sensor on the left side of the engine compartment, mounted just in front of the pressure sensor on the underside of the rear deck, that has an empty terminal (one of two terminals) that this wire might go to. The other wire on this device is black or brown. This device has a hose that comes out one side and goes into another vacuum device (with two other hoses coming out of it), mounted in the same area , and a hose on the other side that goes to the right side of the air distributor manifold.

I have looked at the FI wiring diagrams and cannot identify this device, and the diagrams that I have are in black and white so I can not identify a green wire to see where it goes. I do not want to burn up any electrical device

4) When I turn the key to the "on" position I hear one click, and the fuel pump stays running as long as I leave the key on. I thought that the fuel pump shut off after a couple of seconds?

FYI: the vehicle was in running condition about a week ago (although it would run rough when cold), it was loaded on a transporter under it's own power. when the transporter arrived at my location, the car would not start. The local temperature here was hovering around 52 degrees.

I was thinking maybe the wires vibrated loose while on the transport.

Anybody have any thoughts on the above items?

Thanks, Glen

Sun Jan 08, 2006 10:02 am

Do you have a digital camera to get a picture of those wires and the switch under the deck in the engine compatment. Since it is a '72, it may be part of the EGR system for California.

The loose wire by the battery is just for the old VW diagnostic system. I wouldnt worry about that.
The pump should not run all the time with the key on, unless the engine is running. Check the 3 wire plug that goes into the connector on the side of the distributor.

Sun Jan 08, 2006 5:26 pm

Russ,

You are a wizard at troubleshooting, the 3-wire connector on the distributor was not seated completely! The rubber boot looked like it was fine, but I pushed down on it and the connector seated fully.

After seating that connector, the engine started right up and ran smoothly for approximately 45 seconds and then the engine speed started hunting: down to almost a stall and then immediately goes up to a very high idle (if not more) and keeps repeating that. If I hold the accelerator down it does not vary (hunt) in speed.

I do not know how to post a picture of the mystery switch or sensor in this message or on the site. Can I send you a private message with it attached?

Glen

Sun Jan 08, 2006 6:35 pm

You either have a vacuum hose off, or the idle is set too high. There is a hose next to the distributor that goes to the aux air regulator from the intake manifold. you probably knocked it off working on the distributor.

Sun Jan 08, 2006 6:36 pm

send the pictuer as and attachement to [email protected]