gas tank

[steve]

Ready to attack the fuel tank end of my project on 20069.
I have no internals or piping. Their are 4 holes in the top of the tank.
1. DMCH fuel pump and sender unit in large opening.
2. Fuel supply pipe from gas pump I understand.
3. Old sender unit slot. Screw on cap? Can this cap be purchased to seal that opening?
4. Small 3/8" opening with metal wire inside tank? What is this and what does it do.
Does this connect to the filler tube?

Thanks in advance
Steve

[DavidProehl]

Ready to attack the fuel tank end of my project on 20069.
I have no internals or piping. Their are 4 holes in the top of the tank.
1. DMCH fuel pump and sender unit in large opening.
2. Fuel supply pipe from gas pump I understand.
3. Old sender unit slot. Screw on cap? Can this cap be purchased to seal that opening?
4. Small 3/8" opening with metal wire inside tank? What is this and what does it do.
Does this connect to the filler tube?

Thanks in advance
Steve

1. Correct
2. Correct
3. The screw on retaining piece is part #105161 and appears to no longer be available. Someone may have a suggestion of where to find one, otherwise keep your eyes open for a parts car. I'm guessing there isn't a big demand for this part. This is a retainer has an empty center, so DMCH will send you a circular piece designed to seal the hole.
4. The metal wires are for safe static discharge to avoid static sparks inside the tank. I don't remember it being wired to anything, and this diagram seems to agree.

[steve]

Thank you David, their still is a vent tube on the filler neck where might this connect?
I see the small back hose going to the roll over valve front hose at filler to where?
Steve

[NightFlyer]

Thank you David, their still is a vent tube on the filler neck where might this connect?
I see the small back hose going to the roll over valve front hose at filler to where?
Steve

Part of the evaporative control system:

[steve]

Got it. Didn't see that before.
Thanks
Steve

[steve]

New question for car 20069
1. When the key is turned to position 2 fuel pump pressurizes and engine
components buz. Should the injector spray a small amount of fuel in this
position?
2. Is this the cold start function?

Have stopped at this point because a large amount of fuel is being released
when you go to position 3 and crank her. Enough fuel to drip out of the exhaust header.

3. Am I looking at a fuel distributor problem?

When engine is being cranked spray pattern looks very good from the injectors.

Puzzled in what direction to go.
Already replaced items.
New DMCH fuel pump sender unit.
New Accumulator.
New fuel filter.
Steve

[Rich]

1. When the key is turned to position 2 fuel pump pressurizes and engine
components buz. Should the injector spray a small amount of fuel in this
position? No, they shouldn't.
2. Is this the cold start function? No, it isn't

Partial answers above.

With the key in the ON position the fuel injection system is pressurized (pump turns on momentarily until pressure builds up, then shuts off) but no injectors or start valves should be open. If the rest pressure in the fuel system is still high enough since the last time it was shut down the pump may not even come on at all.

The injection system will (normally) only deliver fuel if the engine is cranking or running.

Are you saying your pump keeps running and running with engine not running and while key is in the ON position?

[steve]

Key position 1 I get A.C. console lights on.
Key position 2 I get pump pressurizing system then shuts off when pressure reached.
Key position 3 I get cranking.

It is position 2 that sprays a small amount of fuel about a thumb nail size into a cup.

Hope this helps
Steve

[NightFlyer]

Key position 1 I get A.C. console lights on.
Key position 2 I get pump pressurizing system then shuts off when pressure reached.
Key position 3 I get cranking.

It is position 2 that sprays a small amount of fuel about a thumb nail size into a cup.

Hope this helps
Steve

If your injectors are cracking open and releasing fuel without application of the throttle, then it sounds like your idle mixture screw is set too deep (rich) and needs to be backed off a bit (lean it out). The screw is adjusted via use of a 3mm allen key. Either that or your injectors are worn out and releasing fuel below the spec pressure rating. As the injectors are relatively expensive to replace, I'd try adjusting the idle mixture screw first.

The idle mixture screw is located in the body of the mixture unit just in front of where the fuel distributor is mounted. If the idle mixture was last set at the factory, then the tamper proof plug will still be blocking access to the screw - you'll need to drill out the plug (but be careful not to damage the screw or anything else on the pivot arm) and then plug the hole after setting the mixture (as it otherwise constitutes a vacuum leak). You really should use a dwell/duty cycle meter to dial in the mixture as close as possible to spec - though to do this assumes/requires a properly functioning lambda system. If you don't have a dwell/duty cycle meter or are constantly running open loop and have removed your 02 sensor, then you can pull the injectors, place them in jars, jump the rpm relay to engage the fuel pump, and set the idle mixture screw to a point just prior to the injectors cracking open and releasing fuel. That should get you fairly close to spec. Don't forget to plug the adjustment screw hole with something after doing this.

Best of luck!