need some help

mystery · 02-23-2013, 03:52 PM

Alright for starters I got a 1985 mazda rx7 12a 1.1ltr carb. First got the car had some problems driving it home all of which pointed to the fuel pump at the time. So after inspecting the fuel filter and finding small pieces of rust I dropped the whole tank and discovered I had a rust issue. I replaced hoses front to back due to cracking and leaking gas lines as well as put a new fuel level sensor and fuel pump. After which all reinstalled car cranked right up and had no issues but what sounded like a misfire. So I replaced spark plug wires with the ngk ones and ngk plugs (guy before had motorcraft plugs... -_-) now it turns over and will either run for a few minutes or crank and die... ive inspected the charcoal canister recirculation andall the mesh Iinside of it appears pretty clogged up would that cause it to do whats happening?? Or is there something im missing???

GySgtFrank · 02-23-2013, 04:26 PM

If I had to guess I'd say you probably have rust particles in the carburetor itself. The charcoal canister shouldn't be causing your problem. A rebuild of the carburetor might be in order to make sure it's clean and has no air leaks. Also check for vacuum leaks while you're at it. The vacuum hoses are probably pretty old and starting to crack/deform, a vacuum leak will drive you nuts trying to diagnose it.

mystery · 02-23-2013, 08:46 PM

Well before I had gotten it the guy before me had already replaced the carb. The jets and all seem to be spraying correctly but I keep hearing about these vaccum lines which judging from what ive already replaced would be a accurate guess.. any idea where to get a diagram of all the vaccum lines?

diabolical1 · 02-23-2013, 10:03 PM

try the FSM.

mystery · 02-23-2013, 11:26 PM

Well I actually work for autozone here in pensacola and had a customer that told me I needed to put a 650 cfm carb in the car and rip out half those vaccuum lines and bypass them all. Has anyone done this??

diabolical1 · 02-24-2013, 03:04 AM

Quote:

Originally Posted by mystery

Alright for starters I got a 1985 mazda rx7 12a 1.1ltr carb. First got the car had some problems driving it home all of which pointed to the fuel pump at the time. So after inspecting the fuel filter and finding small pieces of rust I dropped the whole tank and discovered I had a rust issue. I replaced hoses front to back due to cracking and leaking gas lines as well as put a new fuel level sensor and fuel pump. After which all reinstalled car cranked right up and had no issues but what sounded like a misfire. So I replaced spark plug wires with the ngk ones and ngk plugs (guy before had motorcraft plugs... -_-) now it turns over and will either run for a few minutes or crank and die... ive inspected the charcoal canister recirculation andall the mesh Iinside of it appears pretty clogged up would that cause it to do whats happening?? Or is there something im missing???

for the sake of clarity, you mentioned dropping the tank, but did you have it cleaned? if you didn't then the filter is probably clogged again. you can check the carburetor, like GySgtFrank suggested as well. clean it, check it for debris, then follow the FSM and adjust it. whenever all of this gets sorted, you might want to add a second filter to the system, too.

as for your friend with the Holley recommendation, as a solution, it makes no sense.

mystery · 02-24-2013, 01:07 PM

Yes the tank was cleaned out managed to suckout 3 rocks from the guy before me. before I had takn it somewhere to get the rust takn care of completely and I tried adding in the second filter but the compression wasnt right and it wasnt able to get fuel to the carb... after. Took it out and just put a strait like back in it. Cranked right up >_<

Seanrot · 02-26-2013, 09:42 AM

Ill be honest I didnt read all the stuff above but last time I saw this issue was it doesnt matter how much you clean out the tank if there is rust in it. You have to coat it in something. My guess is your fuel filters are clogged again with rust. get a gas can and run the inlet/return into the can and replace the fuel filters. I bet she will run just fine.

mystery · 03-05-2013, 12:17 AM

Emptyed the tank and used a clear fuel filter this time so that I can see the fuel running. And cars doing the same thing.. cranks then dies after about 15 seconds... started going through the vaccuum lines and have had to replace a couple as well as a one way check valve that I cant seem to figure out where it goes. Any ideas?

diabolical1 · 03-08-2013, 07:10 PM

take a photo of the valve you mentioned.

does it idle smoothly for those 15 seconds? does it remain live when you manually pull the choke?

mystery · 03-16-2013, 11:04 PM

Idle is amazing while it runs choke stays solid and it dies wither the choke is in or not... ive been looking into a bigger carb but having problems finding an adapter plate to mount it now..

diabolical1 · 03-18-2013, 06:20 PM

where is the fuel level in the bowls?

mystery · 03-19-2013, 06:58 PM

Whats best way to check that?

diabolical1 · 03-20-2013, 07:18 PM

there are "sights" (clear glass that allows you to look into the bowls) on either side of the carburetor.

also, there is a solenoid at the front (looking from the driver's side) of the carburetor, make sure it is plugged in.

diabolical1 · 03-20-2013, 08:00 PM

just some basic tidbits I thought I would link for you to peruse ...

Mazspeed carburetor tidbits

02-23-2013, 03:52 PM	#1
mystery Rotary Fan in Training Join Date: Dec 2012 iTrader: (0) Posts: 91 Rep Power: 13	need some help Alright for starters I got a 1985 mazda rx7 12a 1.1ltr carb. First got the car had some problems driving it home all of which pointed to the fuel pump at the time. So after inspecting the fuel filter and finding small pieces of rust I dropped the whole tank and discovered I had a rust issue. I replaced hoses front to back due to cracking and leaking gas lines as well as put a new fuel level sensor and fuel pump. After which all reinstalled car cranked right up and had no issues but what sounded like a misfire. So I replaced spark plug wires with the ngk ones and ngk plugs (guy before had motorcraft plugs... -_-) now it turns over and will either run for a few minutes or crank and die... ive inspected the charcoal canister recirculation andall the mesh Iinside of it appears pretty clogged up would that cause it to do whats happening?? Or is there something im missing???

02-23-2013, 04:26 PM	#2
GySgtFrank Professional Stick Poker Join Date: Feb 2011 Location: Stafford, Ks. iTrader: (0) Posts: 1,005 Rep Power: 15	If I had to guess I'd say you probably have rust particles in the carburetor itself. The charcoal canister shouldn't be causing your problem. A rebuild of the carburetor might be in order to make sure it's clean and has no air leaks. Also check for vacuum leaks while you're at it. The vacuum hoses are probably pretty old and starting to crack/deform, a vacuum leak will drive you nuts trying to diagnose it. __________________ 1979 SA22C (parts of one anyway) http://rotarycarclub.com/rotary_foru...ad.php?t=15585 1975 MG Midget (building) http://rotarycarclub.com/rotary_foru...ad.php?t=18681 1988 N/A SE model FC, dead stock and less than 85k on the clock. This one actually runs, so I don't fuck with it.

02-23-2013, 08:46 PM	#3
mystery Rotary Fan in Training Join Date: Dec 2012 iTrader: (0) Posts: 91 Rep Power: 13	Well before I had gotten it the guy before me had already replaced the carb. The jets and all seem to be spraying correctly but I keep hearing about these vaccum lines which judging from what ive already replaced would be a accurate guess.. any idea where to get a diagram of all the vaccum lines?

02-23-2013, 11:26 PM	#5
mystery Rotary Fan in Training Join Date: Dec 2012 iTrader: (0) Posts: 91 Rep Power: 13	Well I actually work for autozone here in pensacola and had a customer that told me I needed to put a 650 cfm carb in the car and rip out half those vaccuum lines and bypass them all. Has anyone done this??

02-24-2013, 01:07 PM	#7
mystery Rotary Fan in Training Join Date: Dec 2012 iTrader: (0) Posts: 91 Rep Power: 13	Yes the tank was cleaned out managed to suckout 3 rocks from the guy before me. before I had takn it somewhere to get the rust takn care of completely and I tried adding in the second filter but the compression wasnt right and it wasnt able to get fuel to the carb... after. Took it out and just put a strait like back in it. Cranked right up >_<

02-26-2013, 09:42 AM	#8
Seanrot The Newbie Join Date: Jul 2012 iTrader: (0) Posts: 25 Rep Power: 0	Ill be honest I didnt read all the stuff above but last time I saw this issue was it doesnt matter how much you clean out the tank if there is rust in it. You have to coat it in something. My guess is your fuel filters are clogged again with rust. get a gas can and run the inlet/return into the can and replace the fuel filters. I bet she will run just fine.

03-05-2013, 12:17 AM	#9
mystery Rotary Fan in Training Join Date: Dec 2012 iTrader: (0) Posts: 91 Rep Power: 13	Emptyed the tank and used a clear fuel filter this time so that I can see the fuel running. And cars doing the same thing.. cranks then dies after about 15 seconds... started going through the vaccuum lines and have had to replace a couple as well as a one way check valve that I cant seem to figure out where it goes. Any ideas?

03-16-2013, 11:04 PM	#11
mystery Rotary Fan in Training Join Date: Dec 2012 iTrader: (0) Posts: 91 Rep Power: 13	Idle is amazing while it runs choke stays solid and it dies wither the choke is in or not... ive been looking into a bigger carb but having problems finding an adapter plate to mount it now..

03-19-2013, 06:58 PM	#13
mystery Rotary Fan in Training Join Date: Dec 2012 iTrader: (0) Posts: 91 Rep Power: 13	Whats best way to check that?