71 Spider - backfiring, bucking and stalling - please help

71veloce · #1 (**permalink**) 06-20-2005, 04:26 PM

Hi all: I knew I'd be looking for help a lot on this board very quickly, just hoped it wouldn't be this soon or this desperate.

We purchased a 71 Spider a week or so ago. Started up ok, ran fine for a mile or so, then started backfiring, bucking, and ultimately stalling out at idle. Took it to a mechanic, and just picked it up an hour ago - $600 in parts and $600 in labor later we drove it out excitedly - only to find that they never test drove it after "fixing" it, and it's doing exactly the same thing. ("well, it started up fine and we drove it around the shop and it was running great").

What was done: new exhaust manifold, new plugs, wires, cap and rotor. Oil change, tie rods and alignment, but that's not germane...

We're needless to say furious with the mechanic and heartbroken that our baby isn't running after $1200... and of course fully understanding that much more will need to be spent on this car, but we're still upset...has anyone experienced this problem, and if so, could you share possible solutions with us? Any help would be very, VERY much appreciated.

Farace · #2 (**permalink**) 06-20-2005, 04:56 PM

I think the first thing I'd do is pull the plugs and see if they're fouled. I know in another thread I suggested checking to be sure the plug wires were in the correct order, but if it ran fine for a while, that's not it. (Did it run okay for a little while after you picked it up today?)

Any black smoke out the tailpipe?

71veloce · #3 (**permalink**) 06-20-2005, 06:26 PM

the plugs are brand new - when we pulled them out once we got the car home, yeah, they were cruddy. seems to be a recurring problem. Your suggestions are most welcome... the plug wires ARE in the right order, and yes, it ran beautifully for about a mile and a half - we were SO excited! - then the slight bucking started - then the whiplash-inducing stuff... then stalling out at lights if we didn't keep the RPMs up.

not so much with the black smoke, why?

seems like you're always my savior bob... thoughts? suggestions?

**Gubi** · #4 (**permalink**) 06-20-2005, 07:16 PM

Obvious question is: was it sitting for a while before you bought it, and if so how old is the gas? I could see a two-year old tank of varnish crudding up your plugs right quick.

Beyond that you should probably consult with one of the resident SPICA experts.

77SpideRacer · #5 (**permalink**) 06-20-2005, 07:33 PM

Not only varnish but rust clogging the rear filter. Were both of the fuel filters replaced? When the car is bucking, does the fuel light come on?
Did your non-Alfa mechanic made some adjustements to the Spica system? This was an issue with my car.

Quote:

Originally Posted by Gubi

Obvious question is: was it sitting for a while before you bought it, and if so how old is the gas? I could see a two-year old tank of varnish crudding up your plugs right quick.

Beyond that you should probably consult with one of the resident SPICA experts.

**Roadtrip** · #6 (**permalink**) 06-20-2005, 07:35 PM

1. Is the fuel low pressure warning light operational? Does it come on initially when you turn the key on, then go out and never come on again?
2. When was the last time the fuel filters were changed?

Farace · #7 (**permalink**) 06-20-2005, 08:58 PM

I asked about black smoke because it's a sign of a too-rich fuel mixture, which can foul your plugs.

A couple of things came to mind that I'd wonder about, besides what's already been mentioned. 1) Does your mechanic know how to time an Alfa? In other words, does he know the significance of the I, F, P, and M markings on the crank pulley? 2) Were the points changed, too, and if so, was the dwell set properly? (Even suspecting a fuel problem, you want to make sure the timing is correct before touching the fuel.)

3) More of a question to John, who can answer this much better than me: If the TA was bad, and the pump was set rich enough to start okay cold, would it then be much too rich as the engine warms up and possibly foul the plugs? Could this then explain the running okay for the first mile or so and then having the problems described?

71veloce · #8 (**permalink**) 06-21-2005, 05:51 AM

ok, let me see if I can address all the questions:

filters: I know that the front one is brand new - the rear one looks new and is clean, but I don't believe it was replaced yesterday.

it was sitting for a while before we bought it, but we ran through what gas was in it and refilled the tank BEFORE this service (i.e., before these new plugs were put in).

The fuel gauge isn't working, and the fuel pressure light (top left) is permanently on.

we provided the mechanic with the Alfa timing info from Centerline and other resources, and they CLAIM to have checked the timing yesterday.

we've wondered ourselves about the TA, since it runs fine cold then gets nasty when warm. I'll refer to some old posts about checking the TA this morning and we'll run thru those diagnostics.

thanks, everyone, for helping with this...

**papajam** · #9 (**permalink**) 06-21-2005, 05:51 AM

I see no mention of the points/condensor having been changed/adjusted. Unless of course the cars been converted to electronic ignition.

**fetta78** · #10 (**permalink**) 06-21-2005, 06:16 AM

Does the car have a cold start solenoid?
I'm not real familiar with a 71 but if it's fine at start up and once it warms up a bit starts to run rough it may be that. If it does have one just unplug it and see if that improves things.

If not, just ignore me!

I’m just throwin out suggestions that worked on my 78 Sedan!

jrichter · #11 (**permalink**) 06-21-2005, 06:29 AM

Quote:

Originally Posted by 71veloce

The fuel gauge isn't working, and the fuel pressure light (top left) is permanently on.

**Roadtrip** · #12 (**permalink**) 06-21-2005, 07:03 AM

The first thing you need to do is find out why the fuel low pressure warning light is on. It should only flash on momentarily when you first turn the key on (until the supply pump comes on and builds the pressure in the line to at least 7psi).

DO NOT run you engine with the fuel low pressure warning light on. Fuel is used to cool and lubricate the injection pump. Running the engine with the low pressure light on can ruin a very expensive injection pump.

If the "mechanic" you took the car to, let that car go out of the shop with a low pressure warning light ON, he's a . . . . . well, I don't know how to put this delicately so I won't . . . . . . IDIOT.

You either need to find a competent mechanic or do it yourself. Download the fuel supply diagnostics guide at www.wesingram.com/hp.htm.

71veloce · #13 (**permalink**) 06-21-2005, 07:43 AM

Thanks John and everyone - I think we've located a mechanic with a clue in the area - we'll be bringing the car to them later. And you're dead on with the IDIOT comment - for many reasons. How about not test driving the car to make sure the problem for which it was brought in was actually fixed?

All the advice/help is greatly appreciated. We'll let you know how it goes.

thanks again,
Sara

Farace · #14 (**permalink**) 06-21-2005, 08:05 AM

Sara, please do keep us informed. Also, ask the new mechanic if he's familiar with Spica fuel injection. It's not something to be just aimlessly fiddling around with.

Were there really $600 worth of parts put in? I don't see it from what you've mentioned.

71veloce · #15 (**permalink**) 06-21-2005, 04:15 PM

Bob: Sorry, it was only $500 in parts, I added wrong. Big ticket items included a tierod set, an exhaust manifold, and a full gasket set - then just lots of littler things - dist cap, points, thermostats, plug wires, head gasket, thermo gasket, plugs, oil filter, radiator cap, condenser, rotor, radiator hoses, air filter...

The new mechanic has worked on older Alfas - there was a '74 in there when we talked to him this morning. At the very least I don't have to be the one providing him with all the info, like I did with the first one. It'll probably be a week before it gets looked at - it's the only good independent foreign car repair shop in the area so they're booked.

Wish us luck, please!