I was checking out the Precat meltdown thread and have kinda a stupid question, but what caused you to think the exhaust was clogged?



My car has recently started stalling left and ******* right. :( As you know I got the carb rebuilt and it was fine for a few weeks. It lacked a lot of power so we changed the timing, tightened the gas pedal link, and changed the mixture. All a go.



Now it's not lacking as much power, but I usually have to start my car and leave it running for at LEAST 20 mintues before I can back up or go forward because it'll stall. (Saddly, It's an automatic so, no, it's not my fault.) https://www.nopistons.com/forums/pub...IR#>/smile.png



The only other car I've ever had was a 99 protege so I've never dealt with older cars. People tell me that because my car needs to be started with a choke it will need to be warmed up like that. Are they for real? Twenty f'ing mintues of warm up?!



Can someone tell me how to use the choke properly, because I have no clue apparently. I'm using the suggestions the owners manual shows, but everybody I talk to has a different theory on how to use a simple ******* choke.



I start it up with the choke, wait, push in the choke, take the ebrake off and put it in gear. Then I wait with my foot on the brake for probably 5 seconds cause I'm trying to calm myself so I dont break something when it stalls. I take my foot of the brake and slowly move it over to the gas, ever-so-*******-gently I'll push on the gas to back up and as soon as it gets less than a 1/2 an inch down it stalls. It usually doesnt stall the second time, but when I put it in first to drive off it'll stall again.



So could it be choking itself off if the cat(s) were melted? I've never heard of a cat melting until I started reading up on RX7's.... odd.

hmm, no replys. Am i that far out in left field? Or does nobody have a clue? https://www.nopistons.com/forums/pub...R#>/unsure.png

what rpm does it idle at? you are supposed to pull the choke out when its cold and it pops in by itself. you shouldnt *need* the chole for 20minutes though. i bet if you set the idle speed and mixture the prolem will go away



mike

What year is the car?

Is it a 12a or 13b?

Does it have an EGR?

How bad off was the carb and was it professionally rebuilt?

Do you have all of your rats nest hooked up (emissions)?

What made you rebuild the carb?

And last but not least, Do you have a manual for the car?

What year is the car?

It's an 84 GSL



Is it a 12a or 13b?

12a



Does it have an EGR?

A what?



How bad off was the carb and was it professionally rebuilt?

It would stall if you didnt have your foot on the gas the whole time. You'd have to rev it when starting it up because it just wouldn't stay running.



Do you have all of your rats nest hooked up (emissions)?

As far as I know, yes it has all the rats nest hooked up. I'm going to be removing that soon in case there's any vaccuum leaks.



What made you rebuild the carb?

See above.



Do you have a manual for the car?

I have every ******* manual on the planet for this car https://www.nopistons.com/forums/pub...IR#>/smile.png (the Service/shop manual and the haynes, plus a bunch of other print outs on the car)



what rpm does it idle at?

When i first start it up with the choke all the way out it'll rev to about 1200, after the choke is pushe in it'll go down to 750. After i've taken it around the block and I put it in park it revs up to 1200 and stays there.



you are supposed to pull the choke out when its cold and it pops in by itself

The choke has never popped back in :(



i bet if you set the idle speed and mixture the prolem will go away

I've reset the idle speed and the mixture. The mixture was VERY lean before I reset it.

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I'm still looking for ideas, but for right now the damn thing is sitting in the driveway spilling all of its oil because the damn torqe wrench I used on the oil pan wasn't working right and snapped the damn bolts on. https://www.nopistons.com/forums/pub...1047683664.gif As if it leaking oil from the o-rings wasn't enough. **** cheap torqe wrenches and those damn o-rings. https://www.nopistons.com/forums/pub...IR#>/angry.png I should have just did it by hand like my gut told me.



Lately i've been feeling like this: https://www.nopistons.com/forums/pub...1047683358.gif when I get in the car. it gets easier right? :p https://www.nopistons.com/forums/pub...IR#>/smile.png

they only have egr (exhaust gas recirculation) in 80 and 86-88.



hmm i notice on mine (83 mt) that it doesnt exactly have a lot of torque at idle, you almost cant let the clutch out without having to give it gas.



the place to start is the factory sevice manual, they tell you what the idle should be set to for an automatic.



i have my idle mix set a tad rich, it seems happiest that way



it will get easier, these cars have to build a relationship before they let you have reliability



mike

My 82 12a has a stock EGR.

1 Do you think your leaking oil bad enough to be loosing pressure?

2 Does the car act up in neutral or just when you put it in gear?

3 Have you already replaced the fuel filter and checked the pump?

4 Do you have a friend with a spare nikki that hasnt been rebuilt?

5 Do you have a friend who knows transmissions really well, not just how to replace one but the ins and outs?





You can remove the rats nest and then see how it runs, it may be a vacuum problem. Im assuming the hoses are all 20 yrs old, and the rx7 engine compartment gets pretty hot especially in the south where the out side air isnt as cool.

If it still runs rough then you have eliminated a great deal of suspect.

And you can always put it back on.

If you dont want to remove it, look in the back of the haynes 79-85 manual in the revisions section and find your rats nest. Then you might want to take up some kind of calming habit. go through the hoses on at a time and remove them (one at a time) and bend them and replace any that look even rough. and every hose that you remove, look in the book and "triple" check and make absolutly sure that both ends are hooked up in the right place. this isnt very expensive, just time consuming.

The standard idle is 750.

Does it run/idle good in neutral?

Sorry 'bout that didnt see your post before I replied.



It runs great in Neutral. Very smooth, before i got the carb rebuilt it would stutter and die in first or reverse if i didnt have my foot on the gas and the brake simultaneously. Now it's fine as long as I wait for it to warm up completely before I shift it into any gear.



1 Do you think your leaking oil bad enough to be loosing pressure?

No, the one sensor that does work well is my oil pressure and it is, on average, at 60.



2 Does the car act up in neutral or just when you put it in gear?

It only acts up (stalls) when I start it up cold, put it in reverse/drive, let off the brake and press the gas a bit. Sometimes if I let off the gas really quick it won't die, but if i floor it it'll cut off.



3 Have you already replaced the fuel filter and checked the pump?

I have not replaced the fuel filter, but plan to in the next hundred or so miles (no money). The pump has not been replaced.



4 Do you have a friend with a spare nikki that hasnt been rebuilt?

Nope.



5 Do you have a friend who knows transmissions really well, not just how to replace one but the ins and outs?

Yes, the guy I took the carb to runs his own ammco and is vice pres of the florida ammco chapter. He also has experience with 1st gen rx7's.

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That same guy suggested that the gas pedal wasn't going down all the way and we tightened that up. It helped a tiny bit, but not enough to shut me up, so we changed the timing and the mixture. It's running better(actually takes off like normal vehicles), but it's really sad for an rx7 even on the high end rpms. AND it still stalls when cold and i put it in gear.

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When I remove the rats nest, I'm also going to re-route the air duct to in front of the radiator so it gets cold air.



Again, it doesn't run "rough", it just stalls. No sputtering or anything, just shuts off.



******* a it's time consuming! I read up on how to check for vaccuum leaks and decided since I don't have emissions tests down here to just pull the damn thing out. If anything-better fuel economy right?

So i take it nobody's biting on the idea that it might be the cat?? The exhaust really doesn't seem like it's pushing as much as a regular cars exhaust.



I mean, it just kinda leaks out the back, there's little to no pressure on the air coming out of the muffler, whether the car is cold or hot.

clogged exhaust will show itself in a high rpm power loss. if the exhaust was that clogged you'd have a hard time starting it too.



the 750 rpm idle is in gear right?



mike

Yes. it pretty much sucks in all rpms. The higher it goes the better it gets, but better is a relative term.



I really don't have 750$ for a race exhaust :(

Try this before you go spending money.

crank the car and let it warm up a little if you have niehbors that will complain. then:

pull the exhaust from the manifold and tie it to the side really good, out of the way of the exhaust stream.

crank the car up(and let it warm up if you dont have neihbors) and see if it still has problems. if it doesnt, you have a flow problem. if it does, id pull the cat and pre cat for spite, since you live in fl.

autozone sells flex exhaust cheap.

And oh yea, before you put the exhaust back on, sail it around the block a couple of times and see how the motor responds.

I love to run mine with no muffler it feels really good!

make sure you have enough outlet though. rexs love to blow fire!

if you have the small manifold with the short outlet you might think about making a bolt on short pipe.

Can you say tumbling??

I forgot to mention:

It may not idle any better because you would have to tune it to the new format, but dont. The idle should just be DIFFERENT than it was and it should rev smoother without stalling.

So pay special attention to the way it idles and sounds before you take the exhaust off. Get used to the pulses of fire/exhaust so you will remember. the reason you try to memorize it is because I have never heard an exhaust so loud as an rx-7. And it makes it hard to distiguish what your hearing.