Carb adjustments - 77 spider

baggins987 · Post by **baggins987** » Mon May 08, 2006 10:42 pm

Just bought a 77 spider from a coworker; drove it for a week. It was running rich, stalling (cold) and backfiring. I replaced all the plugs (covered with black carbon from running rich). Previous owner said he had it tuned up (timing, etc) last fall, not too sure about the quality of work since it looks like only the first 2 plugs were changed. I took off the carb (32 ADFA), cleaned it, and put on a rebuild kit. Put it on again; seems to start better and run better until it gets warmed up, then it stalls and I can't get it started again till it cools off alot - like 4 hours or more. I followed a manual on setting the choke while I was rebuilding it, but I'm thinking something still isn't right. Tonight I got it started and tried adjusting the idle mix screw and idle adjust screw. After a while it suddenly ran really well for a minute or two - like a line unclogged, or maybe the choke completely released or something and then it stalled - idle went from ~1400 to less than 500, then it died.

Any suggestions? Is the fast idle adjustment a factor in this?

Any leads on where to buy carb parts other than rebuild kits? For example, the choke diaphram pump looks like it could stand to be replaced, but I can't find it either alone or in a kit.

Any help would be appreciated as it's become a point of honor now - the guys in the tool room at work are making bets whether I can get the car running again or not.

Thanks,
Dave

So Cal Mark · Post by **So Cal Mark** » Tue May 09, 2006 1:12 am

that choke pull-off diaphragm was discontinued years ago, then some came available thru the aftermarket. I would think Fiat vendors may still have some. I'll check and send you a pm.
Your car should have ign points unless it's been converted to electronic. What does your car have? Is the idle cut-off solenoid working? Are you sure you don't have vacuum leaks? When you rebuilt the carb, what problems did you find with it that you corrected?

baggins987 · Post by **baggins987** » Tue May 09, 2006 1:26 pm

Ignition has 2 sets of points which I assume are new along with the distributor cap and plug wires (by previous owner).

When I rebuilt the carb I cleaned it really good; the primary had a pretty heavy build up of carbon all over. I replaced gaskets and O-rings; adjusted the bowl float; and tried to adjust that choke pull off diaphragm so that the choke plate was at the proper openings at the different steps on the choke cam.

How do I check for vac leaks? Where can I buy a new idle cut-off solenoid?

BTW, I removed the "throttle" cable under the steering wheel, connected to the pedal assembly. Seems there are some parts missing since pulling it out had no effect (end of the cable did not contact the pedal assy).

Thanks,
Dave

So Cal Mark · Post by **So Cal Mark** » Tue May 09, 2006 1:37 pm

you can easily test the cutoff solenoid; it should have power when the key is on. Disconnect the wire with the key on and you should hear the solenoid click.
check for a vacuum leak by either spraying carb cleaner around the carb base, manifold and hose connections with the engine idling. If you hear a change in rpm, check that spot closely.

John Donohue · Post by **John Donohue** » Fri May 12, 2006 8:42 pm

This sounds amazingly like the problem I am experiencing (see 77 spider stalling and under electrical issues) - could be that my problem is a bad solenoid or vacuum leak as well. These are as good of answers as I have heard this week, so will give me a goal for the weekend. Good luck Baggins - let us know how this pans out for you.

baggins987 · Post by **baggins987** » Mon May 15, 2006 2:07 pm

I haven't had time to do any work on the car this week, except I did check the solenoid and it is working. Will try to find time this week to check the vac hoses.

baggins987 · Post by **baggins987** » Wed May 24, 2006 1:48 pm

I still haven't checked the vac hoses. I did remove the carb and readjusted the choke settings. After I reinstalled it the car started and ran OK (but frequent misfires) for a while, choke released correctly, car still ran OK, but about the time the cooling fan turned on the car stalled and wouldn't restart for hours.

I noticed last time I jump-started it the fuse for the gauges blew. Looking in the manual, the EGR valve is on that circuit also. A quick Googling turned up a note that if the EGR valve is stuck full or partially open "it acts like a vacuum leak resulting in a rough idle, hesitation, and possible stalling." Any thoughts on that? Some previous posts seem to suggest plugging the EGR port - is that for diagnosis only or for normal running? (No emissions restrictions here...)

Now the starter will not turn the engine - a result of endless starting attempts and numerous jumps? Any suggestions?

So Cal Mark · Post by **So Cal Mark** » Wed May 24, 2006 3:53 pm

first you need the basics; good battery and connections and a starter that will turn the engine.
An egr valve that is stuck open will cause rough idling or stalling at idle. I haven't seen an egr valve that works in a Spider in about 10 years, but if you don't have emission testing take it off and plug the openings. Stalling due to a stuck egr won't prevent the car from restarting though. If you're running electronic ignition, it sounds like the module has failed

baggins987 · Post by **baggins987** » Mon Jun 05, 2006 1:26 pm

OK, I think I may have found the problem - or maybe another one. While tracing the EGR plumbing I found the tube had come off the air pump (vac generator?) - which would result in no vac at all. Don't know when it came off (no clamp on it) - would the car run at all with it like that?

Back to the EGR: from the valve the line T's with one leg going to an electrical thingie, the other going to the intake (?) behind the carb, with another line coming off at the same spot and connecting to the carb near the mix screw. So which spots do I disconnect and plug?

So Cal Mark · Post by **So Cal Mark** » Mon Jun 05, 2006 3:25 pm

the air pump hose won't affect the running at all
remove the egr vacuum hose at the carb and cap the nipple

baggins987 · Post by **baggins987** » Mon Jun 05, 2006 11:29 pm

What's the function of the air pump? Emissions?

So Cal Mark · Post by **So Cal Mark** » Mon Jun 05, 2006 11:34 pm

only emissions; it pumps air into the exhaust to aid the catalyst in processing any unburnt fuel

baggins987 · Post by **baggins987** » Wed Jun 07, 2006 10:46 pm

I read in another thread that if the oil on the dipstick smells like gas it indicates a faulty fuel pump. Mine did. A mechanic friend said it could also be a result of flooding the engine during my many attempts to start the car.

Is there a way to test the fuel pump?

So Cal Mark · Post by **So Cal Mark** » Wed Jun 07, 2006 11:13 pm

your mechanic is right, excess cranking can flood the engine and dilute the oil just as a faulty fuel pump can. I'd wait to change the oil until you get the car running properly, then drain and refill the oil sump and watch it for signs of fuel; either fuel odor or oil level that keeps going up

baggins987 · Post by **baggins987** » Tue Jul 04, 2006 1:32 pm

OK, not that the starter is replaced I'm back to battling the carburetor.
I replaced the fuel filter and all the fuel and vapor lines to the carb. Air filter/breather hose not hooked up yet. After a long time trying to start the car (I assume I had to refill all the lines and the filter) the car finally started and ran great - until it warmed up, same as before. Was idling fine ~800 rpm, choke released fine, continued idling fine. Cleaning up around the car I heard the rpm's dropping; hopped in to give it some gas. Noticed the temp gage was near the red zone. Rev'd up to about 2K, temp dropped a bit but engine started missing and backfiring. Let off the gas and the engine dropped back to idle, then slowly died. Tried twice to restart it, no luck.

Is there a temp sensor or something that could be causing this? Vapor lock? Any other ideas?

Carb adjustments - 77 spider

Carb adjustments - 77 spider

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Problems continue...