[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]

Re: [T3] Mystifying starting problem


On 19 Jul 2003 at 3:53, Mike Wodkowski wrote:

> Looking at Bentley it mentions checking that for ground on wire 19 in the
> ECU. How do you do that?

> Then it says to check that #18 is getting 12v from terminal 50 on the
> starter. How do you do that? Exactly how to hook up the Voltmeter to check
> that? 

To work right the brain needs electrical power this means that it has to have 
both a 12V connection AND a good ground. If either of these is missing the 
brain won't work at all. To check  either of these directly you have to pull 
the brain out and check for 12V on pin #18 and continuity to ground on pin #19.

BUT..., the fact that you get the click, click when you turn the key ON tells 
you that the brain IS working, so it HAS both power and ground. So you can move 
on....

> I ALWAYS got the Click-click of the fuel relay right as it should be. Also,
> the fuel pump WAS operating.

Good sign, and good that you took note of this. The only other thing you could 
do would be to turn the key on and go to the engine and press on the throttle 
lever. You should hear a series of injector clicks as you press down and none 
as you let up. If you had another person to turn the key to START you might 
also try listening for the clicking of the injectors then, but they're hard to 
hear over the noise of the starter.

> Another bentley question. It says: "The ECU supplies current to the pump
> during the first 1.5 seconds after the ignition has been switched on. If the
> pump runs during this brief period but then ceases to operate, the relay or
> its wiring is definitely at fault."

> I thought this was what was SUPPOSED to happen, in order to prevent the pump
> from running if the engine wasn't started, for safety reasons.

You're right. I don't know what the Bentley is trying to say here, but it's 
failing. This is a slip-up I hadn't previously noticed.

>  My lines are fine. No gas leaks. But it DID smell very gassy at the
> engine after I had tried to start it a number of times. Like it was flooded.

If it smelled gassy then my guess is that the FI was working and that the 
problem was lack of spark. You might want to check this with a timing light, or 
a spare spark plug. Either way, however, you need a separate person to crank 
the starter for you.

BTW, if you ever suspect that flooding is your problem, this is easy to fix in 
a FI car. Just pull the plastic plug off the fuel pump relay under the dash. 
This will disable the pump so you can clear out the engine. Early FI cars, with 
the A brain tended to flood at times and I got very good at starting my 68 this 
way. I could reach under there and pull the plug with my left hand and turn the 
key with my right. As soon as the engine would start to fire I would plug the 
relay back in and it would start in earnest. I actually did this for years, 
until I found a salvage B brain to swap in there. I've never had this problem 
with any other brain.

It's possible that if your ignition wasn't working for awhile, the engine could 
get flooded and then even if the ignition started to work there was already too 
much gas in there. This trick might then help you out.

> It wasn't a particularly hot night either. Just really humid.
> By the way, I know it doesn't fail often, but I've never been comfortable
> not having a spare pressure regulator on hand. Does anyone have one to sell?

The only one of these I've EVER heard of failing was one of Keith's, which he 
let me take apart and I couldn't find anything wrong with inside. My guess is 
that there was dirt in there, which got dislodged when I took it apart. If you 
really want one I'll GIVE you a spare, as I've never needed one. It's not the 
kind of thing I would ever think of carrying with me, just in case.

-- 
*******************************
Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA
*******************************

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]