FastX7

Ok, so I bought a FB that the PO couldn't get running. He screwed around with the carb and messed it up. Well, I pulled it apart and the float levels were all screwed up. So, I reset the carb and I can get it running... as long as it's above 2500rpms. There's a Spectre (Autozone special) adjustable fuel pressure regulator and fuel pressure gauge in the main fuel line. Also, someone told me he may have misplaced an air bleed when rebuilding the carb?

The regulator is set at 3.5psi but the gauge only reads maybe 2psi when the car is running. The exhaust spits and backfires a little while it's running. Also, the rear tube on the header is glowing red after running for just a little bit. The wiring has all been hacked up and re-done. So is it possible the fuel pump isn't getting enough voltage and making the mixture lean?

The carb that is on it is all stripped down and simplified. I haven't done anything to the car other than reset the float levels. I'm sure there's some other details that'd help identified the problems, so just ask and I'll find out what I can. ANY help would be appreciated!!! I've searched a bunch of threads on here but I haven't got any real definitive answers. My only solution that I know of is just putting on a known good carb.

Kentetsu

If I were you, I'd hit a junkyard and get another carb. There's just no telling what the PO might have done...

blackdeath647

iTrader: (2)

my first guess would be a vacuum leak, also i imagined you cleaned out the carburator when you took it apart. . .

FastX7

Yea, I cleaned it out as best I could. I've checked it over twice for a vacuum leak. There's nothing obvious that's leaking.

I was hoping to avoid that because I haven't been able to find one yet, locally. There's alot done to the car that I'm still figuring out. I want to make sure it's the carb before I replace it.

Also, this is a budget repair. I don't have much money to throw at the car right now.

Rx-7Doctor

iTrader: (13)

Your definitely running lean and a Vacuum leak can cause that issue as well as low quantity fuel output.

Is the shutter valve still installed in the intake and is it in the open position?


The fact that it does not idle or run below 2500 RPM signifies that there is a major issue.
I recommend that you perform a fuel quantity test (replace filter first if have not done so).
Also check for fuel flow out of the tank by disconnecting the feed hose to the filter. You should have a steady stream of fuel. Also inspect the quality of the fuel (is it contaminated with particles or smells like really old gas?

FirebirdSlayer666

iTrader: (3)

Glowing header signifies running rich actually. My FB's header glows on warm up slightly(SA engine and carb) cause it runs rich. I would search on the classifieds for your local region here on the forums and see if anyone has a spare carb

FastX7

Well, hearing that RX-7Dr, I'll just look for a new carb. The PO could have forgotten to put something back into the carb. I know Holley's and can rebuild carbs, but I'm not familiar enough with Nikki's to know if there's anything missing or if he even modified the carb correctly. I'll start looking around to see if someone even has a carb I can borrow. At least with a borrowed carb I'll be able to narrow the problem down.

However, I am going to do a flow test on the fuel first. I suspect that's the problem. I just have a funny feeling about how the fuel system is rigged up now. Once I get that flow test done, I'll post up what I find out there. In the mean time, I'll be keeping an eye out for a carb.

Kentetsu

Don't drink while posting information..

Running rich will result in a cooler motor, while running lean will heat things up.

Most common cause of a glowing exhaust system is running lean, or retarded timing (sparks late, igniting fuel later in the process, still flaming when it hits the exhaust).

Starfox07

The entire manifold, turbo AND downpipe would glow red/orange on my Merkur XR4ti when the timing was off, there were numerous vacuum leaks, the wastegate was malfunctioning (20+psi) and while using 87 octane gas. I swear those engines (2.3t) can withstand more abuse than anything on earth.

(warped the head and blew a headgasket about a year after all that was fixed )

FirebirdSlayer666

iTrader: (3)

I guess I need to buy a timing light then cause my FB sure as hell isn't leaning out(It burns when you stand behind it. VERY rich)