Rx7carl

Nope, just remove and clean all the jets/bleeds/etc. and reinstall.

Kentetsu

Thanks again Carl, you da man!

I won't be able to start the rebuild until next week, but I will certainly let you guys know how it works out! Thanks for all of the support, you guys are great!

Kentetsu

Thanks again Carl, you da man!

I won't be able to start the rebuild until next week, but I will certainly let you guys know how it works out! Thanks for all of the support, you guys are great!

mar3

iTrader: (8)

Double posting mutt...let us know! And by cats, I don't mean replace them, simply unbolt the system and physically look in them with a light to see if the matrix has collapsed or melted...

Kentetsu

lol, sorry 'bout the double posts. Screwy computer or operator error, not sure which.

Unbolting the cats and looking into them would be great, but a twenty year old car in Michigan tends to develop a little rust on parts like exhaust bolts, etc. The only way I'm going to get the cat unbolted is with a cutting torch, so I might as well upgrade at that time. A full RB exhaust is next on my list, just need a little more overtime on my paycheck to take the pain out of it all! I will let you know how it all works out...

Kentetsu

Hey, just an update for those who suggested that my issue was with a clogged cat. I removed the cat and pre-cat today and replaced it all with a 5 foot section of flexpipe. Not very loud and lots more power, but my original problem is still there. Still waiting for my Audi to get out of the shop so I can take my RX7 down for a carb rebuild. Just wanted to let you know. Thanks everybody!

takvanvi

I am interested in the final solution to this thread. I have the same problem on a 83 rx7 with 205,000.

put on new plugs, rotor, cap, wires, fuel filter. Pump flow was checked per haynes and is OK (but I don't have an accurate enough pressure gage to check that psi).

car spools up to about 70 "slowly" as long as I don't have the pedal mashed to the floor. About halfway on the gas pedal works. if at about 3k rpm while driving and I press the pedal past ~1/2way (either just a little past some extra resistance, or to the floor), the car sputters and bogs.

I tried in nuetral as well. it will rev up to about 5k if I run it up slow. just a little more gas to get past 5k and it sputters out. Similarly, if I punch the gas from idle (still in neutral) it will rev up to about 3k where it starts to run rough and stays at 3-3.5k.

Accellertor pump is working as I can see it jet fuel when I actuate the throttle. I will try the trick suggested earlier to carb/clean the jets.

Any other advise, and did you every get your problem figured?

TLER

Recently I have been experiencing the same problems you have. In my 83 GS. I rebuilt the crab, changed plugs, wires, distributor… and so on. Finally I changed the fuse able links and the positive batt. strap and it has purr like a kitten since.

redrx

iTrader: (1)

Im having the same issues as well. Started today...

redrx

iTrader: (1)

turns out the tip of the coil was melted, that'll do it

Kentetsu

Still waiting for the time to do the carb rebuild, but I think its pretty obvious now that that must be the problem. No juice from the AP when I floor the linkage, and no gas to the secondaries. There is gas in both float bowls though, so it must be clogged between the bowl and the venturi, right?

mar3

iTrader: (8)

That would explain the lack of oomph when the pedal is mashed, but by the time you get up in revs, the secondary fuel circuit should have enough signal to be adding gas for decent acceleration. Unless it's fed off the same passageway as the AP pot....

TLER

One other thing you can try is the transitors on the pickup in the distributer could be gone, my friends 83 GX would not fire up and we tracked it down to the transitors, with out them the coil does not colapse fully and you do not get good spark, and it kind of dies when you stomp on it. Let us know if you fix it.

Kentetsu

I had my son put the pedal to the floor a few times last night while I was looking down into the barrels of the carb. While he was doing that, I could see a trickle of fuel dropping into the primaries, but nothing at all going to the secondaries. Both float bowls still have correct level. Let me know if this is not as clear-cut as it seems, but looks to me like I have a fuel passage blocked between the bowl and wherever the fuel drops into the carb.

Rebuilding this thing is going to be a major PITA! Half of the screws have become one with the carb, and already have the heads stripped on them. I might need a replacement.

Man, I'd much rather be driving than wrenching!

Kentetsu

Well, this is interesting...

I can't rebuild the carb because the screws are all corroded and stripped. No junkyard in 70 miles has one. Now I'm putting it back together (not that I got far to begin with) and will nurse it along until I find a carb. At least, that was the plan. Then I found this, and now I need some info.

I took the throttle cable off of the holder so I could pull on it to work the throttle. This way I could look down into the carb while working the throttle. Make sense?

Anyway, looking down into the secondary openings while pulling the throttle cable as far as it goes the little butterfly thingys did not move. Shouldn't they be moving? Now I'm thinking maybe my linkage is messed up or something. I'll try to do some digging and figure out how all this stuff is supposed to work together. Any suggestions, as always, would be appreciated.

Aw ****... Just realized the vacuum part of vacuum secondaries. Damn, thought I was getting closer! I'm about ready to get the hammer out!

Kentetsu

Well, now I have to reconsider everything from the start. I just tried pulling the t-cable again, but this time with the motor running. Guess what, gas IS flowing into the secondaries! WTF!

Now, when I floor it she doesn't die off, just kinda stays where she's at and "buzzs". Even when just revving her I can hear a buz-like quality to the motor.

Also, it seems like I really have to pull hard on the t-cable to get the secondaries to open up. Should it have a really high spring tension or something?

Kentetsu

Switched to mechanical secondaries. No change other than a big stall when I first floor it, then it picks up again but doesn't really accelerate.

Screw it. I'm gonna go wash her and see if that helps.

CarlRx7

so far its not a clogged cat. and its not the secondarys because you switched to mech right.

so its still the ap problem.

when i rebuilt my mikuni, i forgot to hook up the ap linkage, duh, and i could still rev the shyt out of her, but it would bog/stall if i gave it too much gas too fast.

if your in neutral and still can't get the revs over 5k then its not a fuel issue. as i can completely turn off my pump when my car is running no psi. and still rev it up to redline a couple times before she runs outta gas.

how did you convert to the mech secondarys. did you do it right?. thats wut im smelling.

carl.

p.s. with the problem your having with the trailing timing right now. disable it. pull the + wire off of the trailing coil. you dont NEED it to find this problem.

Kentetsu

Oh, ignition has been sweet for some time now. I switched over 2nd gen direct fire a few months ago and haven't had a prob since.

She seems to free rev just fine, its on the road that we're having issues. Giver her the go juice nice and slowly and she'll do 85 or so. But if you're in a hurry forget it, she'll just bog. If you're going thirty or so in 2nd gear and floor it, she just kinda coughs then maintains speed. Won't accelerate though.

Manually working the AP lever, I do not see any fuel being squirted anywhere. My understanding is that the AP helps with sudden acceleration needs. But if I floored it, wouldn't it eventually start taking off if all I was missing was a working AP? Anyway, if there's no squirt I guess I need to fix it anyway. I'll take a look at the manual while at work tonight (lol) and try to address that tomorrow. I'll keep thinking on it.

Kentetsu

CarlRX7, I did switch over to mech 2nd's today but there was not much difference before/after. I used a small zip tie, and watched it working the secondaries while my wife worked the pedal so I'm pretty sure its set up alright. I've seen all the pics before. lol.

xrotaryguy

I had a problem on my rx4 where the throttle linkage would touch an old worn out wiring harness that had to do with the ignition system. Every time I had my foot at a certain position the witre would short out on the throttle linkage and die. Do it often enough or for long enoug and it would blow a fuse too. Look to see if you heve any wires that could be comming in contact with the throttle linkage.

Brian

Kentetsu

Good thoughts man. I'm going to use a small mirror tomorrow and watch all the linkage at work. Long shot, but easy enough to check and eliminate. Thanks.

Kentetsu

Hmm, RX7Carl and CarlRX7..........This is becoming confusing! lmao...

buffalo

Aloha- A couple of years ago my 83 had the same problem(slow to 80, but seemed to run fine), and it turned out to be 2 blown apex seal in the front rotor. Try plugging your finger over one of the empty trailing sparkplug holes on each rotor and crank the engine, you should feel three healthy compression pulses on each rotor. If not drop the exhaust manifold and using a mirror and flashlight check all your apex seals by hand cranking the e-shaft and watching for them to go by in the exhaust ports, looking for any obivous damage. Or maybe it's just a little carbon lock problem, try some MMO in your fuel - Hope this helps- Buff

Kentetsu

Thanks for the thought man. I tried a "poor man's compression check" back when I first started trying to figure this out, and it sounded fine. However, since I have found that I DO have fuel coming out of the secondaries I'm starting to think I should take another look at it.

I'm installing the RB exhaust this weekend, so before I put the header on I'll take a good look inside at the apex seals. Man, I sure hope its not an internal problem!