Bosch Fuel pump Relay

[AndyH2K2]

Hi all,

 

I have a 2002tii, and it won't start. When you turn to start, the fuel pump doesn't run. O and L dash lights are bright. Lights work. The starter motor doesn't engage when I turn the key to ignition. Checked power on wires to the gas tank in the trunk, no power there. Verified the fuel pump works by routing power from the battery. 

 

Thinking now it could be the fuel pump relay - Bosch part number  0 332 014 406. Anyone know where to buy this part? I saw a few ebay auctions for used but want a brand new one, if I can. 

 

Welcome to hear any other suggestions too of course.

 

Thanks for any help!

Edited October 17, 2020 by AndyH2K2

[dlacey]

On a standard tii there is no fuel relay. The fuel pump is driven from fuse no 8 (?), The green wire.

1 hour ago, AndyH2K2 said:

The starter motor doesn't engage when I turn the key to ignition

Sounds like you have a more general problem with the ignition circuit that is affecting fuel pump as well.

Try checking ignition switch itself ?

[PaulTWinterton]

Check the spade connector below the + terminal on the solenoid.  That is the direct connection from the key.  If it's disconnected you'll get zilch when you turn the key.  

 

I would use a test light on the fuel pump connector fitting.  If no power is getting to the pump I would check the wires on back of the ignition switch, behind the key.

[AndyH2K2]

I'll take a look, thanks!

[AndyH2K2]

Spade was connected.

 

Dug this green wire out behind the key, though. Doesn't look good. 

 

 

[Conserv]

And although it’s not a terrible idea, I’m wondering why someone saw fit to install a relay on the fuel pump. I’m guessing that 99%+ of tii’s have no such relay. At minimum, it suggests: (a.) there was a fuel pump issue of some sort, and (b.) someone has messed with the factory set-up.

 

Regards,

 

Steve

 

[AndyH2K2]

Also a good question. The car has a Weber carb conversion. Would there be any reason to install a fuel pump relay with the conversion? I did just install a new fuel pump (which is the one that works well, mentioned above). Wasn't getting any pressure from the previous one (could've gotten more pressure sucking through a straw). 

 

Shot of the relay (unless I'm mistaken).

 

 

 

 

 

 

[Conserv]

2 hours ago, AndyH2K2 said:

Also a good question. The car has a Weber carb conversion. Would there be any reason to install a fuel pump relay with the conversion? I did just install a new fuel pump (which is the one that works well, mentioned above). Wasn't getting any pressure from the previous one (could've gotten more pressure sucking through a straw). 

 

Shot of the relay (unless I'm mistaken).

 

 

 

 

 

 

Just doing our due diligence, Andy,

 

And you’re revealing new evidence!
 

Is the current fuel pump in the original location: under the trunk floor, just ahead of the fuel tank and just to the right of the differential? Below are the original-style fuel pump and holding tank on my ‘73. Is this what you have?

 

Since you mention a conversion to a Weber carb, I wonder if the person who did that conversion needed a fuel pump at the front of the car, sucking, rather than, like the original-style electric fuel pump, pushing fuel. And since the mechanical fuel pump boss on a tii head is not drilled for the pushrod, they “solved” their problem by adding an electric pump near the front of the car. And since they were adding an all-new fuel pump, they installed a relay. This is 100% speculation, without knowing where your car’s fuel pump is located. But if the speculation has any basis in facts, that’s not a good solution if you’re returning the Kugelfischer system to the car.

So where is your new fuel pump located?

 

Regards,

 

Steve

 

 

[PaulTWinterton]

47 minutes ago, AndyH2K2 said:

The car has a Weber carb conversion.

 

That changes everything.  The tii pump puts out 29 psi.  AFAIK carbs require less than 10 psi.  Carb experts required.  I'm out. ?

[AndyH2K2]

Thanks all,

 

The more evidence I can reveal the better. Yep, that's where it is! Right of the diff. It runs and puts gas right up to the carb if we ask it to. It just prefers to avoid being asked to with the dang key. Installed a 4psi Precisiom pump for the low psi-wanting Weber.

 

I cut off that plastic protector that looked like it had some burns on it, and the wire and connectors looked unaffected. 

 

I should be getting some charge on this with the key in start, right? My light tester remains dark.

 

Edit: should mention - I did not do the carb conversion, but did do the new fuel pump. 

 

Edit 2: I'll take some photos of the wiring under the dash today. If I shouldn't have a relay, it seems like things might be a little funky. The relay looks really old... so if someone else installed it, maybe they bought it second hand somewhere. It looks like a dissolving sugar cube.

Edited October 19, 2020 by AndyH2K2
updates

[FunkyLaneO]

That looks like a standard relay from the era, I usually grab a handful of them from the Pick-n-Pull whenever I see an E21 there. Pull it out an look to make sure but you should be able to use any generic automotive relay in that socket.

[AndyH2K2]

Thanks, it has 4 prongs... Bosch part number 0 332 014 406. 

 

Basic googling gives me (1) this - not sure if it's cross-referenced. 

 

or (2) this.

 

or (3), the used ebay route.

 

If it's the right part, sort of feel like if anything it's a quick and cheap check.. but don't want to cause additional problems plugging in a relay that's incompatible.

[jimk]

35 minutes ago, AndyH2K2 said:

plugging in a relay that's incompatible.

Don't think you are going to find one that matches the socket terminal arrangement and is wrong.  The wrong ones won't plug in (these are designed idiot proof).

Edited October 19, 2020 by jimk

[AndyH2K2]

10 minutes ago, jimk said:

(these are designed idiot proof).

 

perfect for me. thanks

[PaulTWinterton]

2 hours ago, AndyH2K2 said:

It just prefers to avoid being asked to with the dang key.

 

I do have more to say.   

 

If you can bypass the ignition switch in the tii fuel pump circuit, test it with your light.   If it's hot then the switch is faulty.

 

Sometimes ignition switches do go bad and need to be replaced.  They get burnt inside.   Bit of a pricey item if I recall.

 

I still don't understand why you have 2 fuel pumps in use.  Wouldn't the low pressure pump get fuel directly from the tank and feed the carb?  It seems you could eliminate the tii pump altogether.