The last couple of weeks I've spent trying to get my Fiat back on the road after a total engine, tranny, and carb rebuild. Heres what I did.
1978 spider, all stock equipment. 32ADFA carb manual fuel pump
Switched to single points.
Static timing set at 0TDC then advanced to 10BTDC (Via distrubitor) for single points
Removed EGR valve and pluged ports at exhaust, intake and carb
Rebuilt carb and adjusted float both vertically and horizontally
Adjusted choke unloader
New: plugs, wires, points, condenser, cap, rotor, fuel filter, air filter
Head was cleaned, valve lash is adjusted to spec
Air pump and injection ports removed and plugged.
Removed all old gas from tank and now have highest grade in there
Replaced EVERY hose to and from the carb back to the tank
The coil tests ok, all cylinders are getting spark, and its getting gas
Battery is fully charged and all contacts have been cleaned. Starter, alternator and regulator test OK.
The Idle cut off solenoid tests ok, but the tip seems to be worn.
Single points is set to .16 spec, timing is at 10BTDC, but dwell angle says 59 deg, should be 55 deg. (Should I back off timing till dwell is 55?)
Idle mix is at one full turn out, but turning screw seems to have little effect on performance. Idle speed is set high to start the car then backed off after warm up.
It will start some times and will sound ok when above 1200, but as I turn down the idle speed screw it starts to run like a tractor. It sounds like it's getting too much air or too little. It idles irradically, it loops, and as its doing this the engine shakes on its flexible mounts.
I'm pretty shure all my vacume conections are tight and routed correctly. If I unplug the idle solenoid while its running, the rpm picks up. I usually run an all metal Fram fuel filter, but I installed a clear one to see if I'm getting gas and if i'm getting rust. When the car is sitting the filter only has a small amount about 1/4 inch of gas at the bottom, when running, its about 3/4 full. I do smell gas in the oil, but that could be from cranking so much. No rust visible at the filter.
I've read through previous posts with similar problems and it sounds that I have a major vacume leak. Tonight I will retighten the intake manifold and the throtle plate. Brake booster has a new hose with clamps on both ends. What else could I check or what else could it be?
I have the origional plugs, I might try to clean them off and see if that makes a difference,
Should I back off timing till dwell is 55?
I have an electric fuel pump and a distributor and coil for a 79. Should I switch these out to see if one of these is the problem?
I have yet to check the fuel pickup at the tank. If this is clogged would that cause rough idle?
Any help greatly appreciated, Restoration is almost complete but I just want to drive it and get it out of my landlords carport. Its been there since Sept and everyday in Hawaii is perfect spider weather.
thanks
Matt Scarton
HELP! Wont run smoothly under 1200rmp
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manoa matt
- Posts: 3442
- Joined: Thu Oct 26, 2006 4:28 pm
- Your car is a: 1978 Fiat 124 Spider 1800
- Location: Honolulu, Hawaii
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manoa matt
- Posts: 3442
- Joined: Thu Oct 26, 2006 4:28 pm
- Your car is a: 1978 Fiat 124 Spider 1800
- Location: Honolulu, Hawaii
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mbouse
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ventura ace
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manoa matt
- Posts: 3442
- Joined: Thu Oct 26, 2006 4:28 pm
- Your car is a: 1978 Fiat 124 Spider 1800
- Location: Honolulu, Hawaii
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racydave
Matt, the dwell is related to the adj of the points, after setting dwell, then re adj eng timing. If the eng was running to lean, such as in a vac leak, the rpms will pick up if you cup your hand over the carb while at idle making it richer. It is possible the float may be set to high, causing gas to overflow into eng, this you could see as drips in throat of carb! You could insp the spark plugs, looking for one that might not be working, i have gotten bad plugs before, in fact the last time I installed a set! Let us know! you know that youre missin all this beautiful snow! You miss it ?
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manoa matt
- Posts: 3442
- Joined: Thu Oct 26, 2006 4:28 pm
- Your car is a: 1978 Fiat 124 Spider 1800
- Location: Honolulu, Hawaii
I'll try everybody's suggestions along with some of my own. I might even make a video so everybody can see and hear whats going on. That might be the bigest help. Does anyone know if you can post videos on flickr? I saw someone posted a video about a ball joint failure a few weeks ago. By the way I moved here from Chicago so, no I don't miss the snow one bit. Sorry guys I don't mean to rub it in.
thanks for the help and keep posting suggestions
Matt
thanks for the help and keep posting suggestions
Matt
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ventura ace
Matt,
You can check compression when cold, as well as warm.
Another worthwhile test is to disconnect spark plug wires one at a time while the car is idling to see what happens. If the engine runs worse when disconnecting a plug, it means that that cylinder was firing and doing some good. Plug that one back in, and check another one. If you find one that makes no difference when plugged or unplugged, then that cylinder is suspect.
alvon
You can check compression when cold, as well as warm.
Another worthwhile test is to disconnect spark plug wires one at a time while the car is idling to see what happens. If the engine runs worse when disconnecting a plug, it means that that cylinder was firing and doing some good. Plug that one back in, and check another one. If you find one that makes no difference when plugged or unplugged, then that cylinder is suspect.
alvon
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So Cal Mark
what you describe as the "tip" on the idle solenoid is the idle jet. If that is worn, fuel will bypass around the jet and cause a very rich condition. Since the engine runs better with the wire unplugged from the solenoid that shows you are getting too much fuel. With the wire unplugged, the idle circuit should be completely closed off. Since the engine still runs, you are getting fuel either around the idle jet or from the main circuit
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manoa matt
- Posts: 3442
- Joined: Thu Oct 26, 2006 4:28 pm
- Your car is a: 1978 Fiat 124 Spider 1800
- Location: Honolulu, Hawaii
Well, after alot of tests and rechecking connections I think it is the idle jet.
#2and 3 cylinders were missing and since they are close to the manifold and the carb, If too much gas was gettin by, it would lead straight to those two. Also if I giggled or turned the solenoid I could notice changes.
I can buy just the jet itself for around five dollars, but they come in various jet sizes. I'm at work and don't have it in front of me, so does anyone have the spec for the jet size it should be stamped on the side.
This is for a 32 ADFA with the 10mm idle cut off solenoid.
Funny thing (not really) is that in 78 weber made two 32ADFA carbs. One with a solenoid that has 10mm threads and one with 8mm threads. The carb on my car (the one I rebuilt) is the one with the 10mm. But I also have the other carb with the 8mm solenoid. If I would have rebuilt that carb instead then there would'nt be a problem.
By the way compression readings were just over 100psi and even across all cylinders, I'll have to thank my machinist who worked on my head.
Thanks for the suggestions
Matt
#2and 3 cylinders were missing and since they are close to the manifold and the carb, If too much gas was gettin by, it would lead straight to those two. Also if I giggled or turned the solenoid I could notice changes.
I can buy just the jet itself for around five dollars, but they come in various jet sizes. I'm at work and don't have it in front of me, so does anyone have the spec for the jet size it should be stamped on the side.
This is for a 32 ADFA with the 10mm idle cut off solenoid.
Funny thing (not really) is that in 78 weber made two 32ADFA carbs. One with a solenoid that has 10mm threads and one with 8mm threads. The carb on my car (the one I rebuilt) is the one with the 10mm. But I also have the other carb with the 8mm solenoid. If I would have rebuilt that carb instead then there would'nt be a problem.
By the way compression readings were just over 100psi and even across all cylinders, I'll have to thank my machinist who worked on my head.
Thanks for the suggestions
Matt
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manoa matt
- Posts: 3442
- Joined: Thu Oct 26, 2006 4:28 pm
- Your car is a: 1978 Fiat 124 Spider 1800
- Location: Honolulu, Hawaii
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manoa matt
- Posts: 3442
- Joined: Thu Oct 26, 2006 4:28 pm
- Your car is a: 1978 Fiat 124 Spider 1800
- Location: Honolulu, Hawaii
wont run smoothly
I am still stumped. I still can't idle under 1200 rpm.
I just rebuilt the 32ADFA Carb with the 10 mm solenoid. The idle jet that I got was for the solenoid with 8mm threads. IAP and Vick wanted 23 for the complete solenoid plus another 18 to 20 for shipping. I would have paid 43 for a solenoid
So I ended up taking the float bowl section from the 8mm carb and merged it with the rest of the 10mm carb. Everything fit together perfectly, I made shure all the main jets and secondary jets, and emulsion tubes were the right sizes and then I readjusted everything and put it on.
With single points, if I get it started, warm it up a little I have to set the idle high, to like 1500 while timing is at 10 deg. Engine runs ok and does'nt miss. At this point I try to back off the idle set screw. When it gets below 1200-1000 then the engine starts to misfire, and it eventualy sputters out and dies. While its around 1500 it does not misfire.
If I got it started, and I have the idle set high, to 1200 and timing is at 10 deg. If at this point, I advance the timing more to 25-35 deg then the rpm pick up and it runs even better. I then try to back off the idle and by the time the set screw no longer comes in contact then the idle is at 1000-12000. At this point it will miss, but not very often.
So the car seems to run the best when timing is at 30-35 deg. With the timing light the mark is almost vertical. But I can't back off the idle enough to get it down to 850 rpm.
I know the solenoid works, and I even put on the new jet. The idle mixture screw still has little noticable effect, unless it's almost all the way in, or more than three turns out.
I even tried an electronic unit from a 79. I tested everything before installing it. I had two, and merged all the parts that tested good. I tried three different controle modules that I had, and one new one that I just bought. I could'nt even get a spark from the coil.
So I switched back to the single points with its accompaning coil. The coil that I have does not have an internal or external ballast resistor, which by the way are not the same thing. I read a few articles this week about points ignition systems, and how they benifit from ballast resistors, sometimes called "points savers". After doing some electrical calculations I found the right resistor for the resistance of my coil. Apparently if points type coils get more than 9volts then they heat up alot, which shortens their life, points too. When youre driving it gets 13 or more volts.
With the ballast resistor installed I could'nt get the car to start. Before this whole fiasco, a few weeks ago when I first got the car to start I did notice that the coil was getting hot, so I took one of the heat sink mountings from a 79 coil.
One gray area ,is the ignition control relay for the dual points 78. The IAP tech page on dual points to single points conversion says nothing about the relay. Should I take it out or try to bypass it in some way.
I'm almost at my wits end, i've checked and tripple checked everything. I have tried many different combinations of components and nothing seems to work.
matt
I just rebuilt the 32ADFA Carb with the 10 mm solenoid. The idle jet that I got was for the solenoid with 8mm threads. IAP and Vick wanted 23 for the complete solenoid plus another 18 to 20 for shipping. I would have paid 43 for a solenoid
So I ended up taking the float bowl section from the 8mm carb and merged it with the rest of the 10mm carb. Everything fit together perfectly, I made shure all the main jets and secondary jets, and emulsion tubes were the right sizes and then I readjusted everything and put it on.
With single points, if I get it started, warm it up a little I have to set the idle high, to like 1500 while timing is at 10 deg. Engine runs ok and does'nt miss. At this point I try to back off the idle set screw. When it gets below 1200-1000 then the engine starts to misfire, and it eventualy sputters out and dies. While its around 1500 it does not misfire.
If I got it started, and I have the idle set high, to 1200 and timing is at 10 deg. If at this point, I advance the timing more to 25-35 deg then the rpm pick up and it runs even better. I then try to back off the idle and by the time the set screw no longer comes in contact then the idle is at 1000-12000. At this point it will miss, but not very often.
So the car seems to run the best when timing is at 30-35 deg. With the timing light the mark is almost vertical. But I can't back off the idle enough to get it down to 850 rpm.
I know the solenoid works, and I even put on the new jet. The idle mixture screw still has little noticable effect, unless it's almost all the way in, or more than three turns out.
I even tried an electronic unit from a 79. I tested everything before installing it. I had two, and merged all the parts that tested good. I tried three different controle modules that I had, and one new one that I just bought. I could'nt even get a spark from the coil.
So I switched back to the single points with its accompaning coil. The coil that I have does not have an internal or external ballast resistor, which by the way are not the same thing. I read a few articles this week about points ignition systems, and how they benifit from ballast resistors, sometimes called "points savers". After doing some electrical calculations I found the right resistor for the resistance of my coil. Apparently if points type coils get more than 9volts then they heat up alot, which shortens their life, points too. When youre driving it gets 13 or more volts.
With the ballast resistor installed I could'nt get the car to start. Before this whole fiasco, a few weeks ago when I first got the car to start I did notice that the coil was getting hot, so I took one of the heat sink mountings from a 79 coil.
One gray area ,is the ignition control relay for the dual points 78. The IAP tech page on dual points to single points conversion says nothing about the relay. Should I take it out or try to bypass it in some way.
I'm almost at my wits end, i've checked and tripple checked everything. I have tried many different combinations of components and nothing seems to work.
matt
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ventura ace
Matt wrote:
By the way compression readings were just over 100psi and even across all cylinders.
100 psi is not all that good for a fresh rebuild (assuming that you have a strong battery and starter, and decent compression gauge). I'm still wondering if the mechanical timing is off a notch somewhere, and may be the reason that it runs better with the dizzy timing advanced so much. How certain are you that the engine is at TDC when the valve timing marks are lined up??
alvon
By the way compression readings were just over 100psi and even across all cylinders.
100 psi is not all that good for a fresh rebuild (assuming that you have a strong battery and starter, and decent compression gauge). I'm still wondering if the mechanical timing is off a notch somewhere, and may be the reason that it runs better with the dizzy timing advanced so much. How certain are you that the engine is at TDC when the valve timing marks are lined up??
alvon
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racydave
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manoa matt
- Posts: 3442
- Joined: Thu Oct 26, 2006 4:28 pm
- Your car is a: 1978 Fiat 124 Spider 1800
- Location: Honolulu, Hawaii
run smooth
I am positive that its timed correctly. I worked all weekend trying different things. After I cleaned and re-lubed the centrifugal advance It seemed to work a little better. Also getting dwell down to 55 deg from 58 helped a little.
At one point late in the day on Sun. I had it at 55 deg dwell, 10 deg advance timming, and I got the rpms down to 850 and it was running OK, but it still had an erratic miss and it eventually sputtered out.
Just listening to the carb at idle, it does'nt sound quite right.
After some reading late Sunday night, I think I may have some carb connections hooked up wrong. I posted the views of my 32 ADFA carb on flickr. Remember that I eliminated the air pump and the EGR valve. Here is the link: http://www.flickr.com/photos/38097470@N00/403739353/
You may want to click on the little mangifying glass to read the item numbers.
#1 CRANKCASE BLOW-BY CONNECTION I have this hooked up to the "T" at the base of the air filter where it meets the crankcase emmissions tube.
#2 FUEL INLET, obviosly its connected to the fuel line from the filter and pump.
#3 FUEL RETURN, connected to the fuel return, and one way valve that goes back to the tank
#4 FLOAT BOWL VAPOR OUTLET, I have this connected to the side of the vapor canister.
#8 VAPOR CANISTER CONNECTOR. This is connected to the top of the vapor canister.
#10 EGR VACUUM SOURCE, This is plugged off, no more EGR
#11 AUTOMATIC CHOKE, these are connected to the intake manifold rear, and the water pump/heater pipe.
#12 FAST IDLE DIAPHRAGM, this is connected to the intake manifold, at a plumbing "T" that also has the brake booster vacume source.
I think #1 connection may be wrong, because when I take off the air cleaner and undo the hose, there is moisture in the hose. Also, I read (The classic car restorers bible) that the foat bowl vapor connection should be hooked up to the air cleaner base. This helps idle somehow.
So if #1 is wrong, then #4 is also wrong. I also have doubts about #12 connection.
Some other points that I picked up from reading:
Ignition points should be grounded to the adjustment plate, via a small "pigtail" wire.
Air pre-heater for air filter will help reduce condensation in carb upon warming up.
Here is what I plan on doint tonight when I get home:
Install new Bosh blue coil ( I'm tires of second guessing my existing coil)
Hook up air pre-heater.
Ground ignition points
Hook up float bowl vapor outlet to bottom of air filter housing
What should i do with the crankcase blow-by connection, and the fast idle diaphragm connections?
I also have'nt been able to find any adjustment procedures for the Fast Idle diaphragm set screw. Could this be why it won't idle at a lower RPM?
I have the specs for the adjustment of the choke valve control diaphragm. But its adjustment requires a special tool. Does anyone know how to adjust it without the tool, or give me the specs of the tool and I can make one. Is this adjustment that important?
thanks
Matt Scarton
At one point late in the day on Sun. I had it at 55 deg dwell, 10 deg advance timming, and I got the rpms down to 850 and it was running OK, but it still had an erratic miss and it eventually sputtered out.
Just listening to the carb at idle, it does'nt sound quite right.
After some reading late Sunday night, I think I may have some carb connections hooked up wrong. I posted the views of my 32 ADFA carb on flickr. Remember that I eliminated the air pump and the EGR valve. Here is the link: http://www.flickr.com/photos/38097470@N00/403739353/
You may want to click on the little mangifying glass to read the item numbers.
#1 CRANKCASE BLOW-BY CONNECTION I have this hooked up to the "T" at the base of the air filter where it meets the crankcase emmissions tube.
#2 FUEL INLET, obviosly its connected to the fuel line from the filter and pump.
#3 FUEL RETURN, connected to the fuel return, and one way valve that goes back to the tank
#4 FLOAT BOWL VAPOR OUTLET, I have this connected to the side of the vapor canister.
#8 VAPOR CANISTER CONNECTOR. This is connected to the top of the vapor canister.
#10 EGR VACUUM SOURCE, This is plugged off, no more EGR
#11 AUTOMATIC CHOKE, these are connected to the intake manifold rear, and the water pump/heater pipe.
#12 FAST IDLE DIAPHRAGM, this is connected to the intake manifold, at a plumbing "T" that also has the brake booster vacume source.
I think #1 connection may be wrong, because when I take off the air cleaner and undo the hose, there is moisture in the hose. Also, I read (The classic car restorers bible) that the foat bowl vapor connection should be hooked up to the air cleaner base. This helps idle somehow.
So if #1 is wrong, then #4 is also wrong. I also have doubts about #12 connection.
Some other points that I picked up from reading:
Ignition points should be grounded to the adjustment plate, via a small "pigtail" wire.
Air pre-heater for air filter will help reduce condensation in carb upon warming up.
Here is what I plan on doint tonight when I get home:
Install new Bosh blue coil ( I'm tires of second guessing my existing coil)
Hook up air pre-heater.
Ground ignition points
Hook up float bowl vapor outlet to bottom of air filter housing
What should i do with the crankcase blow-by connection, and the fast idle diaphragm connections?
I also have'nt been able to find any adjustment procedures for the Fast Idle diaphragm set screw. Could this be why it won't idle at a lower RPM?
I have the specs for the adjustment of the choke valve control diaphragm. But its adjustment requires a special tool. Does anyone know how to adjust it without the tool, or give me the specs of the tool and I can make one. Is this adjustment that important?
thanks
Matt Scarton