Technical Fuel pump replacement 79 spider

[Slotman]

So I need to replace my fuel pump in my 79 spider...my big yellow spider service manual mentions removing a "splash panel" then removing the fuel pump from under the car, I'm not sure what the splash panel is unless it's the metal chin under the lower grill? But I don't see how that would help..it's all the way in the front of the car and not in the way of removing the pump, the welded in crossmember under the pan is more in the way than anything...removing the pump from under the car looks difficult to say the least and it looks like from under the car the only other thing I can remove is the tire, from under the car the crossmember and motor mount is whats in the way, i can acess one of the 2 bolts but cant even see the other bolt although perhaps by braille..it looks like if I remove the alternator and possibly the intake manifold it could be done from above but that's a lot of work so I wanted to ask someone with the voice of experience what's best to do? I try never to let anything beat me so I will persevere no matter what ...thanks in advance for any advice !! Terry

 

[Slotman]

On further examination one bolt and one hose look easy from underneath,
I'm wondering if I don't have the car up high enough to view the otherside, looked like if I'm directly under it perhaps I can see the other side...

 

[Slotman]

This is my replacement fuel pump, the clocking of the inlet and outlet is different than the pump currently on the car by one bolt hole, and the inlet and outlet seem opposite...what is the arrow cast in the pump indicating? I'm assuming it's the outlet to the carb? When I cycle the pump it blows air in my face and the other side does not...however it would be opposite to the existing pump, currently the nozzle closest to the firewall is the inlet, and the nozzle pointing to the drivers side inner fender goes to the carb so I'm confused..

 

[Slotman]

Think Im being a dummy and looking at the pump "upside down" when I turn it over right side up the inlet and outlet appear the same as the one on the car, not "opposite", the only difference is the clocking by one bolt hole...still, I'm assuming the side with the cast arrow is the outlet to the carb and indicating the direction of flow?

 

[Twink80]

Think Im being a dummy and looking at the pump "upside down" when I turn it over right side up the inlet and outlet appear the same as the one on the car, not "opposite", the only difference is the clocking by one bolt hole...still, I'm assuming the side with the cast arrow is the outlet to the carb and indicating the direction of flow?

The cast arrows indicate the direction of fuel flow. You can operate the pump by hand, if you put your finger over the inlet port you should feel suction pressure.
The other option is to fit it to the engine, put some long clear or free lengths of pipe on the pump, fill them with fuel then crank the engine a couple of revs to see which tube spits out fuel. Obvs caution with fire hazzard and don’t use too much fuel!!

 

[Slotman]

Thanks! Think I got it figured out, also i am aware the pump goes over the top, not under the cam, and to bump the motor over if I'm on the high spot on the cam to aid in reassembly, removing the old one should indicate that...think I need to get the car about 4 inches higher to be able to get under it farther, then I should be able to see the other side bolt...

 

[Twink80]

Thanks! Think I got it figured out, also i am aware the pump goes over the top, not under the cam, and to bump the motor over if I'm on the high spot on the cam to aid in reassembly, removing the old one should indicate that...think I need to get the car about 4 inches higher to be able to get under it farther, then I should be able to see the other side bolt...

I have swapped a fuel pump from above with Twin 40’s fitted. You need to jack the pump in n on the mounting bolts as the pump mech is spring loaded. Take it steady and wind in equal ncrements

 

[Slotman]

Great idea about the jack! I did get the side loose on the front of the car side from the top!

 

[124BC1]

So I need to replace my fuel pump in my 79 spider...my big yellow spider service manual mentions removing a "splash panel" then removing the fuel pump from under the car, I'm not sure what the splash panel is unless it's the metal chin under the lower grill?

My interpretation of 'splash panel' would be the sheet metal panel that covers the underneath of the engine bay - it extends from the front lower panel (below the bumper) to the engine crossmember and is attached to the front panel, the frame rails and the crossmember - it has a cut-out to clear the oil pan (oil sump). They usually get discarded because they can be a nuisance to remove as the securing bolts are often found to be seized (frozen).
Here's a pic of it in the Fiat parts manual:-

I once left mine off thinking it wouldn't matter..
But at speeds over 90 mph, I noticed the front of the car going light - steering became lighter and car tended to wander (more than it did normally).

So, if you still have it, then refit it, if not just forget about it., probably won't make much noticeable difference - U.S. spec cars have, iirc, a raised ride height compared to Euro spec so don't handle as well anyway.

 

[124BC1]

On further examination one bolt and one hose look easy from underneath,
I'm wondering if I don't have the car up high enough to view the otherside, looked like if I'm directly under it perhaps I can see the other side...

See if you can get a better view using a light and mirror.

But as I said in a previous answer to iirc 'smahaley', whenever I'm removing something from a car, I always consider the refitting of the same component. If removing it in a certain manner with minimal other parts being removed is going to be achievable but will likely cause me aggravation when trying to refit the same component, then I'll opt for taking off more parts so that I have easy access for both removal and refitting. Plus, with better access and a better view of things , you may spot something you would otherwise have missed.

 

[124BC1]

Think Im being a dummy and looking at the pump "upside down" when I turn it over right side up the inlet and outlet appear the same as the one on the car, not "opposite", the only difference is the clocking by one bolt hole...still, I'm assuming the side with the cast arrow is the outlet to the carb and indicating the direction of flow?

The top of the pump can be separated and 'clocked' by the required amount if you wish. Are you sure that an incorrect pump wasn't fitted in the past? I'd clock the top cover if I reckoned it would allow the fuel hoses to have a better run. I try to keep fuel hoses away from the inlet manifold, as this can become quite hot even though it's water cooled, to prevent fuel overheating issues - some insulation might be a good idea in hot operating temperatures?

Here's a few pics showing the internals of the fuel pump (note; the official Fiat part diagram shows a BCD pump same as the NOS one you have) and the dismantling/reassembly instructions from the Haynes workshop manual for the 124. The important point to follow is - before tightening the pump body screws, the operating lever needs to be pressed fully upwards to correctly position the diaphragm. It's not difficult.

 

[Slotman]

Wow! Thanks as always for your advice and wisdom! I really, as we all do appreciate it!

 

[Twink80]

My interpretation of 'splash panel' would be the sheet metal panel that covers the underneath of the engine bay - it extends from the front lower panel (below the bumper) to the engine crossmember and is attached to the front panel, the frame rails and the crossmember - it has a cut-out to clear the oil pan (oil sump). They usually get discarded because they can be a nuisance to remove as the securing bolts are often found to be seized (frozen).
Here's a pic of it in the Fiat parts manual:-

View attachment 463132


I once left mine off thinking it wouldn't matter..
But at speeds over 90 mph, I noticed the front of the car going light - steering became lighter and car tended to wander (more than it did normally).

So, if you still have it, then refit it, if not just forget about it., probably won't make much noticeable difference - U.S. spec cars have, iirc, a raised ride height compared to Euro spec so don't handle as well anyway.

Great info. I haven’t seen those panels before, my car was 1980 US high ride spec.
That panel will affect underbody aerodynamics and possibly cooling.
Abarth made a rubber chin spokier which looks cool and should push air around not under the car. My car is now lowered to Euro spec, to the point that a sump guard is needed! A previous owner managed to wipe off the sump and oil pump in an accident… I have the repair bill! Highly recommend buy or make a sump guard!

 

[Twink80]

Great info, the later fuel pumps are very different.
Also the splash panel explaines access issues under the car. My car is totally different so my comments although well intended might not apply to your car!

 

[Slotman]

I have swapped a fuel pump from above with Twin 40’s fitted. You need to jack the pump in n on the mounting bolts as the pump mech is spring loaded. Take it steady and wind in equal ncrements

First of all a HUGE thank you for your advice of coming in from the top when removing the fuel pump! It only took me 5 minutes to remove the 2 bolts and 2 hoses and be holding the old pump in my hand! I do have 2 concerns/questions...sorry! , when removing the old pump I was expecting some spring pressure against the bolts as I backed them out but there was none, I am aware the arm of the pump goes over the top of the cam, not under it...I noticed this when I had only backed the bolts out a short distance, the car was running when parked,...even with the new pump it seems I can aim it up over the top of the cam and just slide it in flush to the spacer....no spring pressure..is it possible I just got lucky where the motor last stopped and its not on the bump of the cam that actuates the pump? Or is something wrong here? Also in the enclosed picture am I correct in assuming I'm looking at the spacer still attached to the block? As none came off with the pump...thank you in advance for any advice here! Terry

 

[124BC1]

You were just lucky with where the engine and the auxiliary drive shaft that operates the fuel pump lever happened to come to rest.
The bump on the aux. d/shaft is just a small eccentric, it's nowhere near as big as a lobe on a camshaft operating the engine valves.
The older twin-cams engines had the fuel pump held on by 2 studs with nuts, so sometimes the pump had to be wiggled to remove it off the studs - later engines, such as your's has bolts and nuts, so easier to remove/refit the pump. (Fiat started fitting bolts and nuts instead of studs and nuts on various units from c. the mid/late '70's e.g. the cam box housings to the cylinder head comes to mind).

Your picture does indeed show the insulating spacer still attached to the cylinder block - there's a gasket on each side of this spacer - if there is no sign of leakage at the gasket between the spacer and engine block, I'd be tempted to leave it alone and just fit a new gasket between the new pump and spacer (if you don't have a new gasket, you could re-use the original one if undamaged, maybe apply a slight amount of sealant to ensure no leaks).

As regards a tightening torque figure for the fuel pump mounting bolts, (just in case you were about to ask ) I've never seen one listed, but I'd estimate it as perhaps 12 - 15 lb.ft. (or ft/lbs).
Given that the pump has an alum. alloy flange, I'd just 'nip' it up by hand using a tiny fraction of my immense strength , applied to a short wrench. This is an ability that most (properly trained) Mechanics develop over time i.e. how to tighten things correctly without using a torque wrench - it's a combination of 'feel', judgement and experience. I'd suggest screwing the bolts in by hand, tighten most of the way using a wrench and, for the final tightening, placing a box wrench (or ratchet + socket) on the bolt, hold the wrench in place using your thumb on the ring of the wrench (or the side of the ratchet head) and with your fingers on the beam of the wrench tighten the bolt by curling your fingers towards your palm, as if you were trying to make a fist.

Don't forget to carefully check the condition of the flexible fuel hoses, in fact, given your car has been off the road for some time, I'd recommend replacing them and get new hosing that is 'Ethanol resistant' (over here I use Gates (U.S.) fuel hose). Ditto the flexible hoses at the tank end of the hard lines.
The large filler neck hose that connects to the fuel tank is another area that could give trouble, best renew this also, if in any doubt as to it's condition and it's resistance to Ethanol containing fuel.

 

[Slotman]

124BC1 and twink80, you 2 individuals have been the most knowledgeable and helpful individuals on the vintage spider site! Thank you for your insight and help!!
I'm certain I'm not the only one that appreciates you two! When I removed the old pump the 2 bolts were only finger tight but there was no indication of oil leakage, although I did buy a new spacer, and 2 gaskets from Vicks I'm going to leave that spacer in place...I did a wire wheel on the bolts and applied a dab of grease to them and the tip of the arm on the pump...
I cleaned out the fuel tank that looked fine inside, and blew out the fuel line from the sender all the way to the carburator, all that came out was some stinky gas...no corrosion, installed 2 new filters, and a new 32/36 carburator....tomorrow I will pop the new fuel pump on, add some gas to the empty tank and give the key a crank! A month ago because I had just cleaned both the grounds under the hood, and every electrical Connector I could get my hands on I attempted to start the car with the fuel line unhooked and it started on the first crank and ran smoothly 4 or 5 seconds so I have high hopes it will start, and stay running on gas...thank again you 2!

 

[124BC1]

Iirc, you said your car had been laid up for 12 years?
Have you checked/replaced the timing belt?
There is an age as well as a mileage change interval, iirc, Fiat used to recommend something like 36,000 mls or possibly 3 years?

 

[Slotman]

Haha, the new timing belt has been hanging on the wall 12 years...if it runs, after a drive up the street to the park on 20 plus years old tires I can't find a date code on it goes back in the garage for total new brake system and the timing belt, water pump, tensioner bearing..

 

[Twink80]

Haha, the new timing belt has been hanging on the wall 12 years...if it runs, after a drive up the street to the park on 20 plus years old tires I can't find a date code on it goes back in the garage for total new brake system and the timing belt, water pump, tensioner bearing..

Definately with 124BC on this one. Change the timing belt asap. Its relatively cheap, if it snaps (may or may not) you will need an engine rebuild! These engines are nit clearance engines (ie ones where there is sufficient clearance between the piston at TDC and the fully extended valves)
Aside from the rebuild cost where are you going to get the parts? A head gasket alone is similar cost to a timing belt. Gates products are pretty good quality.
Its a fairly easy job to do, make sure all the covers are replaced. Some people run with no cover as it looks cool…..until a stone or other debris gets between the belt and the timing pulley….bye bye engine!
We had an Alfa 147 years ago, in the handbook the belt change was 50k miles but Alfa downgraded this to 35k, we didn’t know and the belt snapped at 36k! The local Alfa specialist said he had dealt with cars that had been stood for a while and stripped teeth on the belt on first start wrecking the engine. The Alfa belt wrap is much tighter than the Lampredi Twincam so its not quite so sensitive. For me on a cost and effort basis its a no brainer for a car thats parked up over winter. Change the belt!