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the O-rings would keep the coolant from leaking, but definitely would be a vacuum leak of no gasket between intake and block. if freeze plugs were used in the rotor housing, then a coolant leak wouldn't be a problem at all.
Hello mivroum and all, just saw this thread. I have a similar thread going on here: https://www.rx7club.com/1st-gen-gene...00rpm-1144899/
I just purchased a '85 FB with a weber 48 DCOE setup. The car starts and idles fine, but it stumbles around 3000RPM and would no longer accelerate. I see you had similar issue but below 3000RPM. My car drives great below 3000RPM.
Question, on my car vacuum lines from the dizzies are not connected at all. Should they be connected and if so where to? I bought the car from a guy who lives at sea level and I live at 7000 ft. I was advised that jetting is what I need to check and adjust. How is your driving experience now? thanks
Do you have a wideband? That would help a lot knowing what is happening.
What fuel pump are you running?
What is your current jetting?
Have you tuned the 48 at all?
Do you have a wideband? That would help a lot knowing what is happening.
What fuel pump are you running?
What is your current jetting?
Have you tuned the 48 at all?
What is wideband? The fuel pump is Mallory (not sure of the model), I ll pull the jets out and post here what I have. Have not tuned a weber 48 yet but I am technical and I have good documentation (link). Attached is the picture of the carb and the plug:: The car is running too rich, the plugs were charcoal black. The guy I bought it from lives at sea level and I am at 7000 ft. He also had stumbling at 3000 rpm.
air/fuel ratio gauges come in 2 different types, narrow band and wide band. a wide band is more accurate.
I forgot to mention there is a wideband air/fuel gauge inside, I ll post pictures of the readings at idle and at 3000 rpm when it starts to stumble. Also I ll post a video of me starting and driving the car up to the point when it starts to stumble. The car sounds like an awesome real race car. What are the desired A/F readings for a weber 48 dcoe and 13b?
Currently the emulsion tubes are F11 and the idle jets are 65F9.
Still have to check the fuel pressure regulator setting.
You have 2 threads going on this with all the best people involved now. The AFR (read from the wideband) will really help dial in that weber for where and how you drive. I think it was suggested earlier to get one.
Please report back with the fuel pressure setting and AFR at idle, cruise, power, wot, etc. That's how your going to know what jets /tubes etc you need - by the AF #'s. I think j9 gave you some tuning steps in one of these threads.
Now that we know you have a wideband we can definately get that baby running right. But it's going to take a lot of adjustments. The F11 tube is definately wrong.. Read up all you can on this forum about weber tuning for rotaries.
Last edited by Maxwedge; Jun 7, 2020 at 04:00 PM.
Reason: Sounded rude.
It's recent and relevant enough that you can bump it. Its the same topic, except yours is a genuine Weber.
J9fd3s' link is an excellent guide to tuning your new setup.
I love the 1-piece wrap-over intakes for the 12A DCOE conversion. I'm working on an early 4-port 13B build and the only wrap-over choice is this clunky 2-piece design RB used to sell.
Functional but ugly. Once I got this rare gem I decided to get an upright IDA carb, despite no choke in a cold climate. It just looks better to me (on my application... you look great)
me moving forward now...
Use jd's guide and you'll be good. Modern EFI computer cars adapt themselves to any altitude/ humidity/temp but for us carb-cool guys, you gotta tweak it for where you live and drive. Getting it running good (maybe with RX7club's help) will give you a great sense of pride. Probably add an inch to your dick.
Last edited by Maxwedge; Jul 26, 2020 at 05:13 PM.
I have stockport 12A and I went to a 45 DCOE with nearly the same intake manifold.
I simplifies a lot the motor bay, but you ABSOLUTELY need a wideband to set the carb correctly. I installed a AEM uego, the sensor has been welded on the Racing beat manifold where the two pipes join together, but if you can, do one plug per pipe so you can check how each rotor is behaving.
I clearly gained power (ignition is stock, only exhaust is full racing beat, the street one, not the race one), but below 3000rpm I still need to tweak the thing as it struggles if I just hammer the throttle.
Fuel consumption went through the roof, but that is also because my driving has changed (love the noise of the Weber, and I have only done mountain climbs and canyons lately).
At the moment I have (45 DCOE):
-38mm chokes (with 36mm, power was decreasing from 6000rpm)
-F11 E-tube (want to try an F16 to see if it helps with low rpm transition)
-65F9 idle jet (slightly too big, 55F9 too small, I need to try in between)
-55 pump jet
-170 main jet
-190 air corrector.
As I said, I am not happy with low rpm behaviour, so I need to work on it when confinement is over.
It is written everywhere the starter circuit is useless, that is is easy to start. It is true in summer, but not in winter, and I wired the starter again this winter, it hels a lot.
Last remark, I have a Malpassi King fuel pressure regulator set at 0.3barg (4.5PSI) and the stockfuel pump (which is so far OK, but I have a Facet Gold in stock just in case).
hey I have just installed a 48 dcoe on my 85 12a. it will run and idle but is sounds like it has a massive exhaust leak at the exhaust manifold. I don't think I did anything to cause this when installing the weber. Any ideas?
hey I have just installed a 48 dcoe on my 85 12a. it will run and idle but is sounds like it has a massive exhaust leak at the exhaust manifold. I don't think I did anything to cause this when installing the weber. Any ideas?
If your new intake manifold doesn't cover up the EGR port then an exhaust leak is exactly what you've got. The stock manifold has a little rectangular hole where exhaust gas comes up to be mixed in with fresh air and recirculated. Most of us removed the ACV and plugged the hole there but with an aftermarket intake manifold if it was designed for an SA then it will leave the hole in the irons wide open. Got to plug it somehow.
