NEED HELP: 1974 1.8L Will Only Start with Brake Clean, Runs with AFM disconnected only Options

[Nor.Cal.914]

Hello everyone,

I have a 1974 1.8L that needs a new fuel pump and the customer purchased this pump from Pelican:

https://www.pelicanparts.com/More_Info/0439...59&DID=4630

I have already figured out the line routing in terms of inlet and outlet, but I do have a few questions about some other aspects. Being that the stock pump is a 3-port pump, first question is, what was the reasoning behind the 3 ports instead of just an inlet and outlet? My first thought was maybe an internal FPR, but I see there is a one in the engine compartment so that doesn't seem to be the case, but please correct me if I'm wrong! Second question involves mounting the pump. I have a 1975 so I'm not as familiar with how the 1974's were setup. This car has the coil style ring bracket around the pump which I'm now trying to figure out if I can utilize to mount the new pump. Main issue of course is the fact that all 3 lines came out on one side of the factory pump, whereas this pump has inlet/outlet on either side.

So my question is, what have you guys done to mount your pumps either in the same location or where did you place it instead of the factory location? Thank you in advance for the help! (IMG:style_emoticons/default/beerchug.gif)

-Christopher

[technicalninja]

My units have 7 pins!
Check your connector that plugs into the AFM. Does it have 7 recesses (one of which is "un-populated").

If it does, I believe we can make it work.


The flap should ONLY flutter if the engine is being cranked!!!!!

If it's moving at all when the engine is not that's double headed weird!

There's nothing inside an AFM that should move the flap electronically.

Most of the time the extra pin is for fuel pump "on" signal 6 vs 7.
I can work around that easily.
Some run the extra pin for a IAT sensor.
Both are not a requirement for system functionality.

Yes, they are needed for daily operation but not to turn fuel to fire.

The fuel pump drive signal is one of the "normal" failure points and is often bypassed by previous owners.

Most of the time it's a bad contact point inside the AFM and cleaning/adjusting the contact will fix it.

Your deal of no pump with AFM installed and pump with AFM discoed sounds like someone has modified the fuel pump electrical circuit to me.

I also have injector pulse equipment.

I have 10 tons of tools.

Been doing this shit 40+ years...

I can also fix the AC in your daily drivers!

The "way" I'd start diag on your car is to direct drive the pump (jumper with circuit breaker) and get the system running before I attacked the fuel pump circuit.
It's secondary to FI function IMO.

I'd also "base line" the engine with a comp test.

I can usually achieve function with a can of B12 to the point of heating the engine up and/or moving it around.
I hate pushing cars...