chedda_j

K well i just went and baught a new carb, a new starter, and a new alternator. Everything ran the best it has ran for a long long time and then poof shitty power, shitty idle, and bad gas milage. I remind you this is exactly how it was before i installed the new stuff as well.

I have no idea exactly what the problem is but this is what ive covered, checked spark plugs, wires and coils, good for what i can see, yet i dont know how to test to see if the coils are working good are not. The carb was off an old car but like i said, it ran great and with more power than ive ever had. The timing is on fine. But the only thing i can even say is that it seems to be running rich or the fuel isnt properly. Yet my last carb did the same thing so im thinking that the carb might not be the problem.

Fuel pressure seems to be fine but i was thinking of swapping in my new holley pump 350-1050 cfm carb pump, yet im not sure at all what im supposed to do. I want to remove the old pump entirely and mount the new one on the fender wall. But there might be varnish in the tank or something.

THe car isnt blowing blue at all and its definatly not a compression issue. Hard hot starts is a big one. IT will just turn over and over going put put put put and sputtering untill i gently tap the gas and that will usually get her going, then i have to rev the flooding out. The only thing that i did do that i havent done was take the sparkplugs out and clean them. Maybe i should try that too. But to tell you the thruth after i cleaned them the last time the got fuel soaked before use once again so i dont think thats it either. I have maybe 1300 dollars and i need this car in good mechanical use asap.

I know this was a long rant but please help. Btw, trochoid once said something about the floats being stuck?

kgray

What carb are you running? not floats being stuck, but the needle and seat. any little contaminant can cause a sticking issue. if you havent already, add a fuel filter just before the carb to catch anything that snuck past the rear filter.

chedda_j

I actually did that and added a return line large filter to make sure nothing can get past.
What can i do to get that **** out of there?

kgray

You would have to tear apart the carb and clean it again. I wouldnt suggest a filter on the return-a bit overkill. Is this a Nikki carb? What fuel pressure are you running at? Most likely you are running WAY rich.

chedda_j

nikki carb

misterstyx69

iTrader: (142)

the only thing that you can actually do,If it is Crud in the Carb is to Take it off and Rebuild it/clean it.It's Not really all that hard.The float goes up and allows Fuel past the Needle,until the Float Gets to a cetain level.then shuts fuel to the Carb until the float goes down in the bowl.If there is any CRUD in between that Needle and the Seat that it sits on the Carb will get Fuel All the time.the fuel will seep by the Needle/seat,and you will get Excess fuel going into the engine...Suggestion,See if One of the ONLINE Manuals available for first gen Tackles the Rebuilding of the Carburetor..in any case I hope you get your Car Running Properly..Nothing is more satisfying than an RX7 that RUNS!..Take care..STYX.

chedda_j

im running stock so it isnt too rich, like i said, i havent installed the new fuel pump yet. Il take the one off the return line. Would i have to buy a rebuild kit or is there a way just to take it apart and clean it without having to redo anything, this is my daily driver and i want it to run again.

kgray

do you have a fuel Pressure Regulator? how do you know pressure is good? Fuel sights 1/2 full? IIRC there is a screen in the carb that needs cleaning along with the needle and seat. best bet is to tear it down and clean everything, then re-tune. if the carb on there was recently rebuilt, you can probably get away with just cleaning and re-assembleing the carb.

Gomez

Have you stuffed around with the rats nest at all?

chedda_j

the rats nest is gone. has been forever. Never ever been a problem tho. I thought maybe because the carb has mechanical secondaries but i took them off with no help. I took out the plugs just now to see the colour and they are golden brown, but i noticed under load the car will chug at 6500 or 6000, burp and sputter. The fuel pump is loud and annoying right now, but it kinda always has been. I sprayed for vaccum leaks and i noticed no sounds of the engine gaining speed so i doubt thats it. I was saying that the pump was good and the FP was good because i could fill an oil bottle probably in about 15 - 20 seconds.

chedda_j

i guess thats only a gallon per minute at the most, so thats only 60 gallons per hour where as the holley is 97g/h

Kentetsu

Verify that you still have spark on the leading ignition, and check your "teeter totter" on the carb linkage.

Hard starts when hot can be a symptom of timing issues...

joe MAZDA

also check how much voltage your geting to each coil(normal 12 volts to each), and your igniters, sounds like ignition problem!

chedda_j

the plugs are golden brown, like stated above so i dont think its ignition. But, il borrow a voltmeter to check out whats going on, i think i have one but it doesnt work lol.
See i would say timing but i didnt change a damn thing with the ignition when i changed out the old parts. The plugs are brown. Now how about this. When i turn the car on and its warm it will idle to about 800 rpms, then slowly chug its way down to stalling in about a minute. Does that help?

hanman

Sounds like carb.
Don't change the fuel pump yet. If you do, install it where the stock pump is, not on the firewall. You will also have to install a pressure regulator. That is why I recommend you wait on the pump.

There are glass windows in the front and rear of the carb. The pump should fill the carb up so there is fuel halfway up both of those windows. If not, you have a problem. If they are below the halfway mark, you could starve the engine for fuel, above and you could get flooding.

One other thing to do. With the car idling, look down the barrels of the carb. Do you see fuel dribbling in anywhere? If so, you need to reset/clean the floats.

hanman

Oh yeah, ditch the filter after the carb, you are just adding unneeded restrictions.

chedda_j

alright i check it out. Btw why do you need a regulator if the holley is already presset to 7. I thought 7 was the correct psi?

Rotospeed

iTrader: (8)

clean the carb, some times you can take it apart clean it and not find eneything put it back together and it will work. Just clean and oil everything good the smallest pece of dirt or something sticking will mess it all up.

trochoid

iTrader: (6)

Are you saying that you have an aftermarket Holley fuel pump and you're running the stock Nikki carb? If that's the case, then you need to install the Holley 0-4.5 psi fpr. Nikki carbs only need 2.5-3.5 psi, 7 psi is way too much and is overpowering the needles and seats.

chedda_j

ok so i ran some carb clean through it and it really did help alot but also did taking the return filter off. Yet it still isnt running the best, what i dont get is that i can keep turning up the idle to 1000 rpms and in like 10 minutes of driving it will drop back down to about 250. Starting to iritate me just slightly.

joe MAZDA

did you mess with the oil mix adj. on the carb?

cdrad51

If you read carefully, old man, he hasn't installed the aftermarket fuel pump just yet.

trochoid

iTrader: (6)

Old man eh? Have some respect for your elders, you young whippernapper you, lol.

jb5365

iTrader: (1)

If the problem is "running rich" it will backfire (loudly) every time you lift your foot off the gas. Neighbors swore to the police that I was doing a driveby in my driveway!!

chedda_j

^^^^^^ its doing that a bit, but not loud, just a little more rapping than normal. But only when it gets warm. I still have the problem of it cutting out at near 6500 or 4000 going up a hill in fifth. It runs prety strong in first, then worse and worse in every gear, the sputtering happends more and more the harder i press the gas. I dont know whats going on it sounds like maybe a fuel issue or maybe...ignition. I checked the leads with a voltmeter and it said 13.6 at the leading and trailing coil on the larger wire post, then on the smaller i read 13.5 on the leading and 11.2 on the trailing coil. But i dont know how to check to see if they are working properly. Like i said the plugs are golden brown and the new carb helped alot but still lots of issues. god i'm getting angry.
Does any know of any cheap weber or holley setup, ive got abouts 800 bucks and i needs to get this car back to running condition.