[bjwhite]

Ok..been trying to get my 79 GT running.... with MUCH help from VintageRob, we've got the thing starting reliably...it's adjusted to what we think is spot-on (he's got lots of experience tuning his 77 Alfetta GT...even changing out pumps and engines, so I trust him. He knows the procedures and Wes's manual very well.)

So it starts, it idles, it warms up...it revs stationary. But when you drive it, it has absolutely no power. We had everything like it's supposed to be pending a test drive and a mixture adjustment. So I drive it and it's just gutless.

Couple facts: The fuel pump is strong and comes on well. The low fuel pressure light gives me a sub-second flash upon first start and stays out for good after that.

So we start to adjust the mixture--as we turn to richen it up...I drive it again. No change, we start turning more, no change....turning more...no change.

So matter how "rich" we attempt to make it, there is no change...the car is just gutless, even when floored it will hardly make it up a hill. The motor otherwise seems solid.

Since the behaviour didn't seem to change when trying to change the mixture, we're thinking that the SPICA pump on this car is nearly totally failed. Since the fuel pressure seems good, starting and other behaviour and adjustments seem ok--just no power.

Any other thoughts before we start changing out SPICA pumps?

 

[papajam]

Has the ignition timing and advance been checked?

 

[bjwhite]

Sorry yes....timing is also confirmed to be dead on....

 

[Andrew]

You say timing is dead on, but to repeat Jim's question, does the advance work OK? Does it get up to the M mark as you rev it?
Have you looked at the plugs? Is it now rich or lean? Having moved the mixture so much, do you know where you are relative to where you started?
Done a compression test? If it has 120+, spark at the right time, and fuel, it ought to run reasonably.
Andrew

 

[bjwhite]

Good question, not sure of the advance. Also one point I forgot to mention, TA is nearly new and is to the rebuilt spec so we've used a spacer...so this isn't TA related.

I would think though that even if the advance wasn't working, that the car would have at least enough power to make it up a small hill....but it barely does..even when floored.

I have not done a compression test just yet....also, when we were doing this, last time I did look a the plugs were certainly lean looking...

So, we'll test compression and advance. Any further thoughts are very welcomed.

 

[Urbana1750]

I don't know if the symptoms fit as yours seems to behave opposite of what is described in the post, but is the altitude compensator rack return spring intact? See http://www.alfabb.com/bb/forums/carburetors-fuel-injection/5828-broken-compensator-link-spring.html.

As another thing to check, the lack of change with mixture adjustment sounds a bit like the pump timing might be 180 degrees off.

 

[Geoman]

How did you test the fuel pump? Perhaps one or both of the fuel filters is clogged to the point where at high demands there's not enough fuel? Is the breather valve near the gas tank free and clear? I had a similar situation and I changed out the spark plugs and it ran like new.

 

[144]

Check the compensator link spring and the pump timing.

 

[tomhenneka]

Disconnect the throttle rod to the pump. If the car drives the same as with the rod connected, you know for sure that something in the pump is busted.

 

[WJamison]

One thing you can try

Be sure the spring is ok and pump timing correct. Does the thermostatic actuator work? Once I had a car that had been sitting for a while and I ran gas with 10% ATF through the pump to get the rack moving. I would only have 1/2 to 1 gallon in the tank as it will smoke badly when you are running it. After trying this you can dilute the ATF by filling the tank. Worth a try. Will

 

[bjwhite]

TA is dead on perfect--rebuild unit. New spec so we used a spacer of course. We are going to check the spring and pump timing per suggestions here. Supposedly the car used to run VERY strong....from the previous owner. He and his mechanic did suspect a bad pump and he sold it. I just assumed he thought a bad pump because a pump off ebay came with the car, still packed up.

Then again, maybe his mechanic started farting with stuff and messed with the pump timing, we'll see.

Thanks for all of the suggestions. Then I go back to the car and the clutch is completely gone....pedal basically falls to the floor and I can't get it into gear. Lovely.

 

[144]

Disconnect the throttle rod to the pump. If the car drives the same as with the rod connected, you know for sure that something in the pump is busted.

Disconnecting the long rod will cause the engine to die as soon as you open the throttle regardless.

A broken compensator link spring will usually allow the engine to idle, but not run between idle and full throttle. It may run at full throttle, however. I had a link spring break and I limped home by alternating between idle and full throttle. I was living in southern Italy at the time and none of the other drivers took notice of my new driving style. Tutto normale.

 

[tomhenneka]

The rotating shaft in the logic section is supposed to provide more fuel with increasing throttle. If this is not functioning, the pump may provide a relatively constant amount of fuel regardless of throttle. The quickest way to verify a major malfunction is to try to run the car with the rod disconnected. If the engine does not die (due to a super lean condition) when you give it throttle, something is bad wrong in the pump. I suggest this test because it is super easy and fast to do.

 

[bjwhite]

Sounds good Tom.... will do that test too. That is exactly what it seems like....no matter the throttle position, same amount of fuel. It's just gutless. If I have the car in gear and I floor it, I can't get it to rev past 4000 rpm or so...and I'm only moving VERY slow.

This is no matter what the mixture setting is....seems that no matter what, it's getting enough fuel to start and to barely rev...but no more.

 

[Stachowiak]

Have you verified that the throttle plates are opening fully when you fully depress the throttle? If someone had been fooling with things, they may have the cable miss adjusted.

Dick Stachowiak

71 GTV
71 Spider

 

[archeologist]

I would still check timing. It's quick and easy. There's almost 40 degrees difference between idle and max timing, so if it's not hitting max timing, it definitely won't rev.

My 2.0 still feels gutless and tractor-like, and I'm going back to double check the timing again, then go through the SPICA procedure.

But the more I think about it, you should feel some difference if you've made it pig rich. If it's too rich it will fall on it's face as well.

Good luck!
Ian

 

[bjwhite]

I would still check timing. It's quick and easy. There's almost 40 degrees difference between idle and max timing, so if it's not hitting max timing, it definitely won't rev.

My 2.0 still feels gutless and tractor-like, and I'm going back to double check the timing again, then go through the SPICA procedure.

But the more I think about it, you should feel some difference if you've made it pig rich. If it's too rich it will fall on it's face as well.

Good luck!
Ian

Are you meaning ignition timing or pump timing? Ignition timing is right on. Haven't had a chance to check pump timing yet. Trying to sort out some Lancia Beta electrics. Fun, Fun...

 

[papajam]

Ignition timing is right on.

How much advance is there at 5000rpm?

 

[archeologist]

What papajam said. I'm curious if you have full advance at 5000 RPM. If not, that will feel like driving in sand.