Rats Nest Removal for '79 RX-7: A Pictoral
05-30-05, 07:55 PM
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Rats Nest Removal for '79 RX-7: A Pictoral
There are lots of tips and pretty pictures out there to remove the rats nest for the '81 to '85 model cars, but nothing has really been documented for the earlier (and superior 
) SA22C models.
Being an adventurous type with a disdain for trees everywhere, I figured that I didn't need any of that emissions garbage, especially since I have long since removed my thermal reactor, air pump and ACV in favor of a RB short primary header.
So I finally got tired of looking at the jumble of garbage that sits on top of my engine, especially since it didn't do anything except mess up my idle and clutter up the joint. So off it went!
Here's a pic of my engine bay before I removed all the rats nest stuff:
And after the nest was given the old heave-ho:
As you can see, it looks a whole lot better. I've also installed a Home Depot cold air intake, as per the Carl/Pratch tutorial, which seems to help with heat soak during long Solo II events. As an added bonus, there are less things to break and otherwise go wrong with your carb. Essentially all you have to do is remove the two 12mm bolts that hold the two (or three in the case of California) solenoids to the engine, disconnect all the vacuum lines and an electrical connector for the coasting valve and pull the whole mess out.
Once you've done that, you will notice that there was a ground on one of the 12mm bolts, make sure you reattach that ground, because if you leave it out, you will have a very messed up idle and no power. Now here's a vacuum diagram for the '79 model year:
I've circled the nipples on the manifold that you will need to use if you want to retain your vacuum advance, as well as the nipple needed to plumb in your new PCV valve to replace the old ventilation and check valve. Here's a closeup of the new vacuum lines, and below it, an extreme closeup of the manifold attachments for the vacuum advance and the PCV valve:
If you want to retain your vacuum advance, run two long lengths of vacuum hose from the two nipples circled on the diagram to the vacuum pots on the distributor. If you don't care about vacuum advance, just cap the nipples on the manifold and leave the vacuum pots open to the atmosphere.
I don't have to remind you to cap the unused nipples, lest you have a huge vacuum leak to spoil all the smooth idles to come.
Now, to plumb in the PCV valve, here is what I did. I believe that I have done this correctly, but if any of you see any errors, let me know. Jon has posted a quick little reference in another thread on what you need to do to plumb in a PCV valve, and I shamlessly cribbed from that quick walkthough.
You need to use 5/16th emissions/fuel hose and plumb the PCV valve into the nipple on the oil filler neck. I used a PCV from a '90 Dodge Caravan 3.0L. The smooth end of the valve should be plumbed into thefiller neck and the threaded end should be plumbed into the manifold. Next, locate the nipple on the intermediate housing, which is directly below the nipple on the oil filler neck. Run a line from there to the large nipple on the back drivers side of the airbox. Finally, you will need to reconnect the charcoal canister, which is integrated into the lid of the airbox. You will need a 5/16ths tee, so you can run a line from the airbox lid to that tee, which will then go to the carb vent and the fuel tank vent line, which is on the firewall. You will have to clamp the end of the rubber line to the vent line on the firewall, as it is a very loose fit. All the other connections seem pretty tight, but to be on the safe side, clamp those as well. (I have yet to do this, as I ran out of clamps.
)
I belive that covers it. There isn't much to the rats nest on the '79 models, but there are still some pitfalls to overcome, and I hope that this post helps all you SA enthusiasts out.
) SA22C models.Being an adventurous type with a disdain for trees everywhere, I figured that I didn't need any of that emissions garbage, especially since I have long since removed my thermal reactor, air pump and ACV in favor of a RB short primary header.
So I finally got tired of looking at the jumble of garbage that sits on top of my engine, especially since it didn't do anything except mess up my idle and clutter up the joint. So off it went!
Here's a pic of my engine bay before I removed all the rats nest stuff:
And after the nest was given the old heave-ho:
As you can see, it looks a whole lot better. I've also installed a Home Depot cold air intake, as per the Carl/Pratch tutorial, which seems to help with heat soak during long Solo II events. As an added bonus, there are less things to break and otherwise go wrong with your carb. Essentially all you have to do is remove the two 12mm bolts that hold the two (or three in the case of California) solenoids to the engine, disconnect all the vacuum lines and an electrical connector for the coasting valve and pull the whole mess out.
Once you've done that, you will notice that there was a ground on one of the 12mm bolts, make sure you reattach that ground, because if you leave it out, you will have a very messed up idle and no power. Now here's a vacuum diagram for the '79 model year:
I've circled the nipples on the manifold that you will need to use if you want to retain your vacuum advance, as well as the nipple needed to plumb in your new PCV valve to replace the old ventilation and check valve. Here's a closeup of the new vacuum lines, and below it, an extreme closeup of the manifold attachments for the vacuum advance and the PCV valve:
If you want to retain your vacuum advance, run two long lengths of vacuum hose from the two nipples circled on the diagram to the vacuum pots on the distributor. If you don't care about vacuum advance, just cap the nipples on the manifold and leave the vacuum pots open to the atmosphere.
I don't have to remind you to cap the unused nipples, lest you have a huge vacuum leak to spoil all the smooth idles to come.
Now, to plumb in the PCV valve, here is what I did. I believe that I have done this correctly, but if any of you see any errors, let me know. Jon has posted a quick little reference in another thread on what you need to do to plumb in a PCV valve, and I shamlessly cribbed from that quick walkthough.
You need to use 5/16th emissions/fuel hose and plumb the PCV valve into the nipple on the oil filler neck. I used a PCV from a '90 Dodge Caravan 3.0L. The smooth end of the valve should be plumbed into thefiller neck and the threaded end should be plumbed into the manifold. Next, locate the nipple on the intermediate housing, which is directly below the nipple on the oil filler neck. Run a line from there to the large nipple on the back drivers side of the airbox. Finally, you will need to reconnect the charcoal canister, which is integrated into the lid of the airbox. You will need a 5/16ths tee, so you can run a line from the airbox lid to that tee, which will then go to the carb vent and the fuel tank vent line, which is on the firewall. You will have to clamp the end of the rubber line to the vent line on the firewall, as it is a very loose fit. All the other connections seem pretty tight, but to be on the safe side, clamp those as well. (I have yet to do this, as I ran out of clamps.
)I belive that covers it. There isn't much to the rats nest on the '79 models, but there are still some pitfalls to overcome, and I hope that this post helps all you SA enthusiasts out.
05-30-05, 09:23 PM
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I should also point out that I have removed my dashpot and the solenoid that raises the idle for the air conditioning. The dashpot went bye-bye 'cause it makes it MUCH easier to take the carb apart on the car for quick adjustments, and the solenoid got tossed when I took out the A/C.
05-30-05, 09:27 PM
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holy crap you are a GOD.. I am so glad you did this.. you are now my favorite person in the world. i may have to keep my car now.. since i am off for the next 2 days i am getting this over with.. how much did you pay for the pcv ?
05-30-05, 09:48 PM
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The PCV valve was 4.98 CDN at my local parts store.
The dashpot attaches to the rear of the carb. It's essentially a vacuum operated solenoid, which keeps the throttle from slamming shut abrubtly on decel. It's also a real pain in the *** when it comes to working on the carb, because the way it's attached pretty much makes taking the carb apart on the car an impossibility. I've found that it's much easier to take the carb off these cars in parts, which allows easy access to the bolts holding the throttle body onto the manifold.
Edit: be sure and reload the thread, I've edited the pictures to add some captions to ensure that everything is clear.
The dashpot attaches to the rear of the carb. It's essentially a vacuum operated solenoid, which keeps the throttle from slamming shut abrubtly on decel. It's also a real pain in the *** when it comes to working on the carb, because the way it's attached pretty much makes taking the carb apart on the car an impossibility. I've found that it's much easier to take the carb off these cars in parts, which allows easy access to the bolts holding the throttle body onto the manifold.
Edit: be sure and reload the thread, I've edited the pictures to add some captions to ensure that everything is clear.
Last edited by MosesX605; 05-30-05 at 10:06 PM.
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05-30-05, 10:23 PM
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Originally Posted by evil_motors
okay so if leave the dashpot do i have to do anything different? or how hard is it to take the dashpot out
05-30-05, 10:43 PM
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Originally Posted by evil_motors
is there a pic of the dashpot so i know what i am looking for?
05-30-05, 11:29 PM
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Originally Posted by evil_motors
is the dashpot the same as the throttle opener in the picture you posted?
05-31-05, 12:18 PM
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well hell yeah.. this needs to be a sticky.. i just did all of that and damn is my car running sweet now.. i think it is running better now than it did when i got it
05-31-05, 09:33 PM
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DO MAKE NOTE:
Do *not* disable the solenoid rack or the air pump if you still have the thermal reactor/heat exchanger installed on the car!
To do otherwise will risk mongo thermal reactor meltdown.
Do *not* disable the solenoid rack or the air pump if you still have the thermal reactor/heat exchanger installed on the car!
To do otherwise will risk mongo thermal reactor meltdown.
05-31-05, 09:43 PM
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ok... so do you think it will work about the same as an 83 FB? I am fed up with my vacuum leaking POS rats nest, BUT I want to keep my AC for now. I JUST installed a new engine 2 weeks ago, huge power increase runs great at 2500 rpm's or more but idles like hell. Am about to rebuild the carb this coming weekend as this is my daily driver.
05-31-05, 09:52 PM
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Originally Posted by ArmySoldier
ok... so do you think it will work about the same as an 83 FB?
06-01-05, 06:05 AM
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Originally Posted by peejay
DO MAKE NOTE:
Do *not* disable the solenoid rack or the air pump if you still have the thermal reactor/heat exchanger installed on the car!
To do otherwise will risk mongo thermal reactor meltdown.
Do *not* disable the solenoid rack or the air pump if you still have the thermal reactor/heat exchanger installed on the car!
To do otherwise will risk mongo thermal reactor meltdown.
Unlike an exhaust manifold, the thermal reactor NEEDS a fresh air source in order to operate, otherwise it can burn out from the high temperatures. In that way, it's much like a catalytic converter. I don't know how well the air pump would function without all the doohickies and whatchitz in the rats nest.
06-06-05, 12:31 PM
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hmm, i have an 1980 SA and i dont have a fuel tank vent line that is described in the tutor.
I tried removing the rats nest with the FB tutor and afterwards it cant hold idle at all!
It has been a problem for nearly a year now, and sorry to say im very close on giving up my rex right now
Read here about my problem (I paypal som money to the guy who helps me out)
https://www.rx7club.com/1st-generation-specific-1979-1985-18/serious-idle-problems-422554/
I tried removing the rats nest with the FB tutor and afterwards it cant hold idle at all!
It has been a problem for nearly a year now, and sorry to say im very close on giving up my rex right now
Read here about my problem (I paypal som money to the guy who helps me out)
https://www.rx7club.com/1st-generation-specific-1979-1985-18/serious-idle-problems-422554/
06-06-05, 03:12 PM
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Originally Posted by JokkVahl
hmm, i have an 1980 SA and i dont have a fuel tank vent line that is described in the tutor.
I tried removing the rats nest with the FB tutor and afterwards it cant hold idle at all!
It has been a problem for nearly a year now, and sorry to say im very close on giving up my rex right now
Read here about my problem (I paypal som money to the guy who helps me out)
https://www.rx7club.com/showthread.php?t=422554
I tried removing the rats nest with the FB tutor and afterwards it cant hold idle at all!
It has been a problem for nearly a year now, and sorry to say im very close on giving up my rex right now
Read here about my problem (I paypal som money to the guy who helps me out)
https://www.rx7club.com/showthread.php?t=422554
