My first project car!!!(problem with the idle
11-09-09, 12:16 AM
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My first project car!!!(problem with the idle
hey guys i...by some miracle just got a sa22c rx7 12a with a 4 speed manual from my dad who bought it new in 1980. he was going to get rid of it because it was just sitting in my driveway and not being used(mainly because it was broken) so when i expressed interest in fixing it and making it my project he gave it to me...HOORAY!. I will admit that it needs work, i mean its been sitting in a garage in Pennsylvania for 10 years...but it does run(ish). So i wanted to make this my sort of blog of my progress on the car with pics of course...and i have a lot of questions.
First off...my experience with cars is moderate...i've worked mostly on my 1997 honda civic cx, you know basic stuff like dc sports header, aem cold air intake,...and a few other things. However, I'm not really familiar with rotary engines.
I managed to get it running fairly well but my idle was ridiculously high something like 3800, my first thought was a vacuum leak or the throttle plate was sticking turns out both were true. the leak was coming from a hose that does...i have no idea what il post pics tomorrow...but i patched it and then fixed the throttle valve and choke, then i turned the idle speed screw as far down as it would go and i also made the fuel to air mixture as lean as it could go. all of this brought down the idle rpms to about 2200 which is a lot better but still not good enough.
my question is...what else can i do or what else could be wrong that would cause a high idle...could i still have a vacuum leak or could it be something else.
ill post lots of pics tomorrow and talk more about what i want to do with the car.
First off...my experience with cars is moderate...i've worked mostly on my 1997 honda civic cx, you know basic stuff like dc sports header, aem cold air intake,...and a few other things. However, I'm not really familiar with rotary engines.
I managed to get it running fairly well but my idle was ridiculously high something like 3800, my first thought was a vacuum leak or the throttle plate was sticking turns out both were true. the leak was coming from a hose that does...i have no idea what il post pics tomorrow...but i patched it and then fixed the throttle valve and choke, then i turned the idle speed screw as far down as it would go and i also made the fuel to air mixture as lean as it could go. all of this brought down the idle rpms to about 2200 which is a lot better but still not good enough.
my question is...what else can i do or what else could be wrong that would cause a high idle...could i still have a vacuum leak or could it be something else.
ill post lots of pics tomorrow and talk more about what i want to do with the car.
11-09-09, 01:21 AM
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be prepared to fall outta love with the honda first off. soon as you drive this thing you realize how much better the RX-7 is over a little 4 banger. I'm not familiar with the 80 nikkis and know very little about them in the first place. It took me some time to bring my Idle down. to a reasonable RPM. With sitting for years your probably going to need to rebuild the carb.
I'll let kentetsu guide you further on carb's. I don't wanna steal his line.
you can find performance parts at respeed, mazdatrix, racing beat, the junkyard. the list goes on. not as much selections as the honda aftermarket. body kits can be found from mariah and a few other places. be tastefully though.
I'll let kentetsu guide you further on carb's. I don't wanna steal his line.
you can find performance parts at respeed, mazdatrix, racing beat, the junkyard. the list goes on. not as much selections as the honda aftermarket. body kits can be found from mariah and a few other places. be tastefully though.
11-09-09, 09:25 AM
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Everything you ever wanted to know about
your carb (but were afraid to ask): www.sterlingmetalworks.com
Performance parts: www.re-speed.com
Welcome aboard.
.
your carb (but were afraid to ask): www.sterlingmetalworks.com
Performance parts: www.re-speed.com
Welcome aboard.
.
11-09-09, 10:37 AM
#7
Please don't rice it...
Your idle with stock intake when correct should be about 750, AFTER the choke times out; 2000-2500 is normal starting RPM with the choke pulled.
High idle on a car that hasn't been borked with (just been sitting neglected) is almost always a vacuum leak issue, or a plugged jet. Since the car was "not running" before it was put to pasture, likely something went wrong previously.
Figure you're probably going to have to replace a lot of vacuum lines, just due to age. A carb rebuild is probably in in order, but the fact that it will start and run at all means your problems are likely relatively minor.
Your idle with stock intake when correct should be about 750, AFTER the choke times out; 2000-2500 is normal starting RPM with the choke pulled.
High idle on a car that hasn't been borked with (just been sitting neglected) is almost always a vacuum leak issue, or a plugged jet. Since the car was "not running" before it was put to pasture, likely something went wrong previously.
Figure you're probably going to have to replace a lot of vacuum lines, just due to age. A carb rebuild is probably in in order, but the fact that it will start and run at all means your problems are likely relatively minor.
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11-09-09, 05:37 PM
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heres some pics of the car and the engine. it needs some work but right now im trying to find any vacuum leaks...are there any relatively inexpensive performance upgrades that you guys recommend.(by inexpensive i mean below a few hundred dollars)...ph and in the last picture i found a large leak in the hose i circled, i only had duct tape on hand so i used that to patch it up although i think that there might still be a leak. what i'd like to know is what is that hose for?
Last edited by Forsythe93; 11-09-09 at 05:46 PM.
11-09-09, 06:03 PM
#9
That hose is the heat riser hose; provides warm air for the intake until a shutter inside the air cleaner closes. Not your problem - - it's not a vacuum line.
In the FAQ thread on this section, there's a link from which you can download the factory service manual. you'll find it a goldmine!
Outside of some surface rust and mess in the engine compartment, car looks to be in pretty nice shape.
If you look rearward from the hose you circled, you'll see a black hose shaped like a question mark. That's the brake booster vacuum line, and one of the most-common causes for large vacuum leaks. It dries out on the underside and cooks.
Good luck with the project; 80's rock!
In the FAQ thread on this section, there's a link from which you can download the factory service manual. you'll find it a goldmine!
Outside of some surface rust and mess in the engine compartment, car looks to be in pretty nice shape.
If you look rearward from the hose you circled, you'll see a black hose shaped like a question mark. That's the brake booster vacuum line, and one of the most-common causes for large vacuum leaks. It dries out on the underside and cooks.
Good luck with the project; 80's rock!
11-09-09, 10:58 PM
#11
car looks great, welcome to the 7 club. Remember that from now on, you will forget about honda, it will be that beautiful 7 in your driveway(by beautiful i mean only to your eyes, unitl its fixed lol) My sujestion is to rebuild the carb, i bought my car idling at the same rpm and after a rebuild and a rats nest removal and all new vaccum lines, the car runs at around 650 all day long. Good luck with the project.
11-10-09, 11:25 AM
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Do you have to pass emissions testing? If not, I'd start removing every single part that doesn't absolutely have to be there. Clean and paint what is left, inspecting and replacing parts as needed.
Lot's of work, but if you plan to keep her then that's the way to do it in my opinion. Welcome aboard.
.
Lot's of work, but if you plan to keep her then that's the way to do it in my opinion. Welcome aboard.
.
11-10-09, 01:04 PM
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Nope i just checked and in VA antique cars are exempt!!.
you said that i should start removing everything i dont need...what dont i need?
right now im still searching for that vacuum leak...is there any trick short of removing every single hose that will help me find it?
oh and what do you guys recommend that i do to clean up the rust under the hood?
you said that i should start removing everything i dont need...what dont i need?
right now im still searching for that vacuum leak...is there any trick short of removing every single hose that will help me find it?
oh and what do you guys recommend that i do to clean up the rust under the hood?
11-10-09, 01:35 PM
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Also im trying to take out the rats nest so i can rebuild the carb more easily..are there any good tutorials for that. for the carb rebuild, any kit recommendations? i found one but im not sure if its any good
http://www.drivewire.com/vehicle/maz...uild-kit/#1980
i just ordered a model specific vacuum hose kit with 6mm and 3.5mm hose
http://www.drivewire.com/vehicle/maz...uild-kit/#1980
i just ordered a model specific vacuum hose kit with 6mm and 3.5mm hose
Last edited by Forsythe93; 11-10-09 at 01:44 PM.
11-10-09, 01:46 PM
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its actually better to leave the original hoses on there, i'd suggest either leaving it alone, or waiting to replace em. each hose does something different, so unlike the honda, its important which ones go where. its not so bad with the 1st gens, but the FC/FD guys have more problems AFTER replacing the hoses than before.
all the carb kits are basically the same, its just a bunch of gaskets.
11-10-09, 04:58 PM
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do an oil change, 10 year old oil is not good, also the gas may not be any good. try running some seafoam through the car. could break up some of the junk in the carb. definitly clean everything! rebuilding the carb is probly the best thing to sort out the high idle issue. welcome to the club!
*side note, a kid i know has a civ like your with a k20. i drove it and it was pretty quick!
*side note, a kid i know has a civ like your with a k20. i drove it and it was pretty quick!
11-17-09, 07:19 PM
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hey guys, been a while...happy to say that i got the idle down to a steady 900 and with a little tuning maybe lower. Engine compartment is starting to look a lot cleaner with all new hoses and no more air pump/rat nest. Also just installed a new intake assembly with a k&n filter. I have new brake exhaust and suspension systems coming because my brakes are really rusted, my shocks and springs are all from 1980 and i'm looking for an easy hp gain with the exhaust.
I really want to put in a 5 speed tranny because right now i have a 4 speed manual and that 4th gear doesn't quite get the job done...been searching the forums and i have no idea where to start...could someone point me in the right direction? Ill put some new pics up in a few days.
I really want to put in a 5 speed tranny because right now i have a 4 speed manual and that 4th gear doesn't quite get the job done...been searching the forums and i have no idea where to start...could someone point me in the right direction? Ill put some new pics up in a few days.
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