Sterling & all other carb gurus
10-26-02, 07:39 PM
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Sterling & all other carb gurus
Don't throw money that you already said you don't have at this yet. Check the vacuum diaphragm box. Try removing the spring. See if there is a good clean seal all the way around the box.
OK thanks for the advice Sterling, I wish I would have read it more thoroughly when I originaly recieved it. Anyway here's what I did, I removed the spring from the inside of the accel. pump. It seems to have made my accceleration problem quite a bit better, but not cured (almost). So even though this seems ovbious, I must ask, what should I do next? Replace the a.p., or is there something that I'm not aware of I need to check/change first.
OK thanks for the advice Sterling, I wish I would have read it more thoroughly when I originaly recieved it. Anyway here's what I did, I removed the spring from the inside of the accel. pump. It seems to have made my accceleration problem quite a bit better, but not cured (almost). So even though this seems ovbious, I must ask, what should I do next? Replace the a.p., or is there something that I'm not aware of I need to check/change first.
10-26-02, 09:46 PM
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Come on a little help please, I think I'm finally getting close. This is the first thing I've done thats actually made diff. Bottom is what the car was doing, and here is what it's currently like.
For the most part it's still the same, but now when I floor it, it gets that extra kick much sooner. Right now the soonest I've noticed it was 3K rpm, but it still takes off sluggish if I dont rev it high and drop the clutch. Plus I dont know if I'm looking at the right part but I pulled what I think are the jets and they looked fine (I saw the light! when I looked through them lol).
If you haven't read my previous post I'm having accel. problems. I've changed plugs, fuel filter, & the pump, plus I got a Mazda guy to come out. He got it to idle smoother, plugged a hose (shutter valve I think), adjusted the mixture screw, checked the compression, checked for vac. leaks, and set the timing. This of course didn't fix the problem. Which is, when I accelerate, I have to floor it to get any serious power. Plus if while accelerating I let off the least bit I lose most all of my power. The only way to get it to gain the power back is to let all the way off and floor it again, or push in the clutch rev it up and then drop the clutch while staying on the gas. The only fuel thing I have yet to do is clean the primary jets. If thats not the problem is there any new suggestions, eg. exhaust, seals, and ect............... I'm just stumped.
For the most part it's still the same, but now when I floor it, it gets that extra kick much sooner. Right now the soonest I've noticed it was 3K rpm, but it still takes off sluggish if I dont rev it high and drop the clutch. Plus I dont know if I'm looking at the right part but I pulled what I think are the jets and they looked fine (I saw the light! when I looked through them lol).
If you haven't read my previous post I'm having accel. problems. I've changed plugs, fuel filter, & the pump, plus I got a Mazda guy to come out. He got it to idle smoother, plugged a hose (shutter valve I think), adjusted the mixture screw, checked the compression, checked for vac. leaks, and set the timing. This of course didn't fix the problem. Which is, when I accelerate, I have to floor it to get any serious power. Plus if while accelerating I let off the least bit I lose most all of my power. The only way to get it to gain the power back is to let all the way off and floor it again, or push in the clutch rev it up and then drop the clutch while staying on the gas. The only fuel thing I have yet to do is clean the primary jets. If thats not the problem is there any new suggestions, eg. exhaust, seals, and ect............... I'm just stumped.
Last edited by pk7tanner; 10-26-02 at 09:52 PM.
10-26-02, 09:58 PM
#3
Nikki-Modder Rex-Rodder
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Alright, I just spent 20 minutes looking up the old threads to relearn the history of your problem.
Some things stuck out at me...
I suggested that your cats could possibly be clogged. You dismissed this as a possibility because there is significant backpressure present at the tail pipe.
This makes NO DIFFERENCE! You don't know what that pressure is like under load at hi rpms (how could you, right?)
Sooooo, that (in my mind) is still a possibilty. The other thing that adds to that as a possibility is that you said the plugs were fouled- So bad, in fact, that it would'nt start. If your plugs look like that, what do you think your cat looks like?
I'm not saying definitively; Just that it's still a possibility that should be investigated.
Accelerator pump...This thing can cause a real pain in the ***. It is the first thing to go in a carb that has sat around for awhile because the system is like a squirtgun, and uses tiny steel check ***** as flow valves. These succumb easily to the "backyard mechanics bain" of varnish.
Varnish will cause the checkballs and the tiny brass wieghts that are on top of them to get very sticky, and not to move freely allowing fuel to pass. You simply don't get a shot of fuel when you need to open the throttle quickly.
BUT...- This Does Not Sound Like Your Problem!!!
You may indeed be suffering from this as one of your problems, but it's not what's causing no power while cruising up a grade.
The fact that you say there is some improvement since you removed the secondary spring in the vacuum diaphragm housing tells me two things...
First of all, it tells me that you DID NOT read my carb artical like I told you to, and it also tells me (coupled with the fact that your plugs were fouled) that you may be getting too MUCH fuel. That really could only happen if your return line was blocked. And your air filter was really really really dirty.
This is a much more likely scenerio with a carb using larger than stock jets, a shitty regulator, and an aftermarket kick-*** fuel pump.
There is still too much unknown data. Remove the variables one at a time just like Craig said, and then proceed to the next one on the list.
Start by removing the four bolts on your exhaust manifold, and pulling it 1/4 inch away from the engine. Drive. Don't worry- it'll stay put. It's louder n' hell, but super fun!
You will know without a doubt inside of 30 seconds on the road if clogged cats are the problem when you cook your tire tread off!
Then, if that aint it, put it back together, and remove the smaller diameter hose from the carb. There is a metal piece after about six inches. This is a check valve. Means flow can only go one way. Realize it's there. Ignore it for a second, and blow thru the hose. -Hard. You should be able to blow through. There's alot of resistance, but you'll know for sure.
If You Can't- then try removing the checkvalve and small section, but keep them together the same way they were. Do it again. If you still can't, then you have a blockage of gummed up fuel line under the car, in the rear, up by the tank. But if you can now, then that means someone accidently put that check valve back on the wrong direction.
Blow thru the end to be sure, and put it on correctly.
...And read my damn write-up! (Don't do any of the mods. Just read it.)
Also, is the fuel level (with the car running) exactly in the center of the glass windows on each side of the carb? (The sides of the carb are facing front and back in relation to the engine)
What did the old fuel filter look like? What did the air filter look like? What did the plugs look like?
...And I mean be as detailed as you can...especially about the plugs.
-We will get you kickin *** in your Rx7!!!
Some things stuck out at me...
I suggested that your cats could possibly be clogged. You dismissed this as a possibility because there is significant backpressure present at the tail pipe.
This makes NO DIFFERENCE! You don't know what that pressure is like under load at hi rpms (how could you, right?)
Sooooo, that (in my mind) is still a possibilty. The other thing that adds to that as a possibility is that you said the plugs were fouled- So bad, in fact, that it would'nt start. If your plugs look like that, what do you think your cat looks like?
I'm not saying definitively; Just that it's still a possibility that should be investigated.
Accelerator pump...This thing can cause a real pain in the ***. It is the first thing to go in a carb that has sat around for awhile because the system is like a squirtgun, and uses tiny steel check ***** as flow valves. These succumb easily to the "backyard mechanics bain" of varnish.
Varnish will cause the checkballs and the tiny brass wieghts that are on top of them to get very sticky, and not to move freely allowing fuel to pass. You simply don't get a shot of fuel when you need to open the throttle quickly.
BUT...- This Does Not Sound Like Your Problem!!!
You may indeed be suffering from this as one of your problems, but it's not what's causing no power while cruising up a grade.
The fact that you say there is some improvement since you removed the secondary spring in the vacuum diaphragm housing tells me two things...
First of all, it tells me that you DID NOT read my carb artical like I told you to, and it also tells me (coupled with the fact that your plugs were fouled) that you may be getting too MUCH fuel. That really could only happen if your return line was blocked. And your air filter was really really really dirty.
This is a much more likely scenerio with a carb using larger than stock jets, a shitty regulator, and an aftermarket kick-*** fuel pump.
There is still too much unknown data. Remove the variables one at a time just like Craig said, and then proceed to the next one on the list.
Start by removing the four bolts on your exhaust manifold, and pulling it 1/4 inch away from the engine. Drive. Don't worry- it'll stay put. It's louder n' hell, but super fun!
You will know without a doubt inside of 30 seconds on the road if clogged cats are the problem when you cook your tire tread off!
Then, if that aint it, put it back together, and remove the smaller diameter hose from the carb. There is a metal piece after about six inches. This is a check valve. Means flow can only go one way. Realize it's there. Ignore it for a second, and blow thru the hose. -Hard. You should be able to blow through. There's alot of resistance, but you'll know for sure.
If You Can't- then try removing the checkvalve and small section, but keep them together the same way they were. Do it again. If you still can't, then you have a blockage of gummed up fuel line under the car, in the rear, up by the tank. But if you can now, then that means someone accidently put that check valve back on the wrong direction.
Blow thru the end to be sure, and put it on correctly.
...And read my damn write-up! (Don't do any of the mods. Just read it.)
Also, is the fuel level (with the car running) exactly in the center of the glass windows on each side of the carb? (The sides of the carb are facing front and back in relation to the engine)
What did the old fuel filter look like? What did the air filter look like? What did the plugs look like?
...And I mean be as detailed as you can...especially about the plugs.
-We will get you kickin *** in your Rx7!!!
10-26-02, 10:32 PM
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Ok the plugs are black, just like plugs get after they've been used for a while, I bought new ones but I didn't realize they were junk (Autolite's). When I put my old plugs back in the autolites were white like they had got too hot. The old fuel filter wasn't too bad, just a little bit of gunk and I just was running it right now without the air filter, but it's also mildly dirty, should pobably be replaced. I wish I could go into more detail but I have to work until wednesday and probably wont be to do anything until then.
Thank You for your Help, CARB GOD aka Sterling
P.S.
I read you'r write up but it was mostly stuff I didn't understand. It's one of the things I have printed, but since then I have learned a fair amount more and it may make more sense to me now. I will read again.
Thank You for your Help, CARB GOD aka Sterling
P.S.
I read you'r write up but it was mostly stuff I didn't understand. It's one of the things I have printed, but since then I have learned a fair amount more and it may make more sense to me now. I will read again.
10-27-02, 01:06 PM
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Nikki-Modder Rex-Rodder
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Originally posted by pk7tanner
Thank You for your Help, CARB GOD aka Sterling
Thank You for your Help, CARB GOD aka Sterling
The fact that your plugs were white is extremely important!!!
I will look over all the threads and data again to see what you have and have'nt done, and what we might've missed.
...We'll get 'er cookin.
10-27-02, 11:43 PM
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I'll be eagerly awaiting you'r next response. Sorry didn't mean to offend you, is DOG BRAC ok? J.K. Also, I was wondering, if I didn't have to worry about emissions testing, what could I do with my exhaust to give me more bhp and not cost me an arm & a leg.
I also, while sitting here, thought of a few more bits of info. My car seems to be running rather rich, there's a small bit of pop/backfire on decel., it's becoming increasingly hard to start, my primary jets only seem to put out about half as much fuel as my seconary jets (based on my opening by hand), and my mpg seems to keep getting worse, I tend to drive fast but 11.87 mpg is pretty bad if you ask me. Thats all I can think of now.
SEE YA!
I also, while sitting here, thought of a few more bits of info. My car seems to be running rather rich, there's a small bit of pop/backfire on decel., it's becoming increasingly hard to start, my primary jets only seem to put out about half as much fuel as my seconary jets (based on my opening by hand), and my mpg seems to keep getting worse, I tend to drive fast but 11.87 mpg is pretty bad if you ask me. Thats all I can think of now.
SEE YA!
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10-29-02, 02:53 AM
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Oh yeah I also pulled what I believed to be pri. jets (the stem-like pieces with little holes at the lower half that you remove with a flathead?), they were fine as far I could tell. So I guess that's not my problem.
So now that know that's not it I'm down to the A.P. & the cat. So if it is the cat how can I bypass it w/o having to replace it? I also forgot to tell you that the float bowl level is at or above half. Lastly what color should the inner part of the A.P. be?
So now that know that's not it I'm down to the A.P. & the cat. So if it is the cat how can I bypass it w/o having to replace it? I also forgot to tell you that the float bowl level is at or above half. Lastly what color should the inner part of the A.P. be?
10-31-02, 03:38 PM
#10
Airflow is my life
Originally posted by pk7tanner
Oh yeah I also pulled what I believed to be pri. jets (the stem-like pieces with little holes at the lower half that you remove with a flathead?), they were fine as far I could tell. So I guess that's not my problem.
So now that know that's not it I'm down to the A.P. & the cat. So if it is the cat how can I bypass it w/o having to replace it? I also forgot to tell you that the float bowl level is at or above half. Lastly what color should the inner part of the A.P. be?
Oh yeah I also pulled what I believed to be pri. jets (the stem-like pieces with little holes at the lower half that you remove with a flathead?), they were fine as far I could tell. So I guess that's not my problem.
So now that know that's not it I'm down to the A.P. & the cat. So if it is the cat how can I bypass it w/o having to replace it? I also forgot to tell you that the float bowl level is at or above half. Lastly what color should the inner part of the A.P. be?
11-01-02, 07:29 AM
#12
Airflow is my life
Yes, if your precats arent already hollowed out from the exhaust, they should be hollowed out via screwdriver. They dont do much for emissions reduction except when the car is cold and they tend to self hollow and clog the main cat after many miles.
11-10-02, 01:05 AM
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All right, check it out, I removed the manifold nuts and drove it around for a little bit (as instructed), nothing but noise, it actually barely stayed running. So you got anymore tips for me guru's? I cant think of anything to try, except to rebuild the carb and replace A.P. Come guys there's got to be something I'm missing.
Even if I'm getting spark could my coils be a problem? I'm still leaning towards a solution that's related to carb somehow, because the only thing that has any differance so far was removing the spring from inside the A.P. So I guess my next step will be replacing the A.P. and if that doesn't work, I'll try rebuilding a carb swapping it. After that, if it doesn't fix the prob., the REX's new name may be, Two Bits, the price of a 45 shell.
Even if I'm getting spark could my coils be a problem? I'm still leaning towards a solution that's related to carb somehow, because the only thing that has any differance so far was removing the spring from inside the A.P. So I guess my next step will be replacing the A.P. and if that doesn't work, I'll try rebuilding a carb swapping it. After that, if it doesn't fix the prob., the REX's new name may be, Two Bits, the price of a 45 shell.
11-10-02, 01:53 PM
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One other thing, what was the interesting bit of info regarding the improvement I got from removing the spring in the A.P. The fact that removing it is the thing to have made an improvement. I've done everything you've suggested so far, gimme knowledge Sir.
Thank You
Thank You
11-12-02, 02:18 AM
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Forget all the stuff I said about the AP what I was talking about this whole time was the damn secondary diaphragm box. So tommorrow I'm removing it and converting the linkage. Your right Sterling I needed to read you'r write-up again, and again, and again, and again, and again, and again, and again, and again. But heah I admit I'm a novice.