acceleration issues :(
#1
acceleration issues :(
hey there... so i rebuilt the carb and drove the truck with out any issues for almost a month now, sunday the truck starts to slowly lose power. this morning it barely could move its self, i've got a lawn mower with more power than this is putting out. i replaced the ignition coil and inspected all the vacuum lines, wires, checked mounting bolts and what not and no issues. when i step on the accelerator it takes about 10 seconds for the engine to start to rev up. i took the aircleaner lid off to look down the carb in idle and blipped the throttle and got a nice spray of raw gas in the face. (good thing i wear glasses). to me this does not seem normal and almost seems to be the source of my performance issues. i was wondering if any one on here may know the cause of this spray of gas from the primary barrel. also i know its not the float level since this is the 5th carb i've rebuilt and tripple checked the levels both free hanging and pushed up. the ignition timing was also set to 8 degrees BTDC like it should when i put the carb back on. i'm realy hopeing the engine is not on its way out.. please help a girl out.
#2
Way back I had a 68 VW 1300 with a carburetor. When you blib it the accelerator pump sends extra fuel through a jet into the barrel. The jet was shaped like a "n". So the fuel went up, made 180 degrees, then sprayed down.
This jet fell off, went into a cylinder and busted my engine.
Find out if your carburetor should have a jet like this. The thing that looks like a faucet:
This jet fell off, went into a cylinder and busted my engine.
Find out if your carburetor should have a jet like this. The thing that looks like a faucet:
#3
nope, its a 2 barrel solex carb, the primary venturi has a brass tube that spans the inner small air horn all the way across and the secondary has it only going half way across with what looks like a vent tube set at an angle at the top of the secondary, all the fuel spray is only coming up the primary and stops when the engine goes past 1400rpm. also forgot to mention that i have the idle speed screw turned all the way in and still will not idle over 640 rpm. i checked my fuel pressure and showed 4.3psi between the pump and carb, so thats within spec. my timing at idle is set to 7 degrees BTDC, spark plugs are clean and still like new, egr valve works, but i hear a constant click coming from the vacuum duty switch that has 3 hoses and 2 solenoids on it thats mounted on the right fender. i have never heard clicking sounds from this before until last night. could this be the source of my problems? just wondering it for some reason is sucking fuel through some place that isn't supposed to have anything wet.
#4
nope, its a 2 barrel solex carb, the primary venturi has a brass tube that spans the inner small air horn all the way across and the secondary has it only going half way across with what looks like a vent tube set at an angle at the top of the secondary, all the fuel spray is only coming up the primary and stops when the engine goes past 1400rpm. also forgot to mention that i have the idle speed screw turned all the way in and still will not idle over 640 rpm. i checked my fuel pressure and showed 4.3psi between the pump and carb, so thats within spec. my timing at idle is set to 7 degrees BTDC, spark plugs are clean and still like new, egr valve works, but i hear a constant click coming from the vacuum duty switch that has 3 hoses and 2 solenoids on it thats mounted on the right fender. i have never heard clicking sounds from this before until last night. could this be the source of my problems? just wondering it for some reason is sucking fuel through some place that isn't supposed to have anything wet.
If you know the exact model carburetor you may look for images online. Porsche used Solex double barrels and there is a ton of Porsche experts on this planet. ( I.e.: Description of the Solex 40 P II - 4 Carburetor).
You could also try clamping off the vacuum lines to that thing-a-ma-jig and see if it makes a difference.
The best of luck, nikkievix. I'll keep watching this thread but I don't think I have a chance to solve the issue.
#5
You say you have a 2 barrel Solex!
I have your answer!
You need to do this: https://www.mazdaforum.com/forum/maz...version-30671/
Mazda Mikuni/Solex carburetor -- Weber conversion; DONE!! - The Garage Gazette
QUOTE: When I started to accelerate, the engine would bog down and smoke like a chimney. Knowing that these engines have notoriously finicky Mikuni Solex carbs, I decided to tackle this "smogger" carb head on.
Sounds like pollution control issues, vacuum line issues.
There is a lot of unnecessary pollution/vacuum lines with stock so upgrade toa Weber and minimize all that crap.
BEFORE & AFTER PICS:
I have your answer!
You need to do this: https://www.mazdaforum.com/forum/maz...version-30671/
Mazda Mikuni/Solex carburetor -- Weber conversion; DONE!! - The Garage Gazette
QUOTE: When I started to accelerate, the engine would bog down and smoke like a chimney. Knowing that these engines have notoriously finicky Mikuni Solex carbs, I decided to tackle this "smogger" carb head on.
Sounds like pollution control issues, vacuum line issues.
There is a lot of unnecessary pollution/vacuum lines with stock so upgrade toa Weber and minimize all that crap.
BEFORE & AFTER PICS:
Last edited by UseYourNoggin; 03-21-2013 at 02:30 PM.
#7
Good luck.
#9
Not following this thread other than this as I am not a Mazda expert. What you post with raw gas out of the carb tells me either the float is too high, or has a hole in it, and not shutting off the fuel feed from the pump, OR the needle valve is worn, and not shutting off. With that if gas isn't running out of the top of the carb into the venturis, I'd say float is too high allowing too much gas for the carb to handle.
#10
float is new, carb rebuilt less than a month ago, new needle valve and seat and fuel level is at the line on the sight glass. only other place that fuel seems to be where it shouldn't is in the red striped line going from the carb to the high altitude compensator valve.