Not getting fuel through pump after head rebuild

[MarkVIII]

I would like to start off by saying that this forum has been an invaluable tool for me in my many adventures with repairing and improving my 1980 Fiat Spider. Between the advice I gathered on these forums and Matt from Midwest-Bayless spending a few hours with me on the phone over the past two years I have learned a lot about Lola (that's my Fiat's name, couldn't help myself).

She is a Spider 2000 model that I have lightly modified with an 1800 intake manifold, FI water neck, 32 ADFA weber carb, FI 4-2-1 exhaust manifold and downpipe, and just recently pulled the head and resurfaced it, lapped the valves and replaced head gasket and the cam tower gaskets.

However, after this most recent rebuild which was brought on by coolant flowing from the front three spark plugs, the car will not pump fuel through the mechanical fuel pump at all. I can manually pull fuel through the lines with a vacuum pump and also pump fuel through the pump and up into the carb by pushing the lever up and down by hand. It ran fine before the rebuild other than the last 30 seconds in a parking lot.

I have replaced the manual fuel pump with a new one and the check valve and that did not help. I can't figure out why the car won't pump fuel as I have lined up the cams, aux shaft and crank to TDC on number 4 and the car will run if I pour gas through the carb without knocks or rattles. Have I missed something crucial? Both my old fuel pump and the new one will not pump fuel when installed on the aux shaft.

[gchocevar]

Mark,

I made the same modifications you did in 2010 on my 79. The only way I could get mine to start was to pump the gas for about a minute while cranking. Once it started the mechanical pump was fine. If I left the car for a week, I had to go through the whole pumping procedure again.

I tried almost all the recommendations in the post and articles. I finally put an electric fuel pump and filter in the trunk wheel well with a regulator near the carb. My problems of 7 years of pumping were over. Maybe some of these carbs for the 1800's were originally made for an electric fuel pump?

Greg

[MarkVIII]

Thank you for the reply, I gave that a try last night and nearly killed the battery but could not get the pump to work. I pulled the pump off and stuck a screwdriver into the port in the block to find the lobe on the aux shaft and couldn't find it. So I tore it back down and pulled the belt again and spun the aux shaft pulley by hand to check for the lobe. The aux shaft is not spinning or is missing inside the block as far as I can tell so I think I have a pretty good idea what has to happen next. Thank you for the tips though I really wish that had worked!

[bobplyler]

Did they replace the AUX shaft during the rebuild? If they did, they might have included a shaft with no lobe. Easy fix. Block off the pump and put an electric pump in.

[bobplyler]

BTW: If the aux shaft isn't spinning, the oil pump isn't either.

[piperstan10]

I would definitely go with electric fuel pump in the spare wheel well. Also would recommend installing a fuel pressure regulator.