dre_2ooo

I had this problem posted in my rally car build thread, but I'm making a new post since that was moved to the non-tech section... and this is a tech problem.

Basically, I am running a stock '85 Nikki on a 13B from a GSL-SE. I used an adapter plate to mount the intake manifold to the engine. The guy I bought it from had a holley 900 carb on there that he kept (we drove it to my house and then he took the carb off). So I know the engine is good and can run.

I rebuilt a used carb that I bought and put it on the car. I stripped it of all emissions, etc... from the carb and dead-headed the return since the aluminum return line on the car was cut in the engine bay and also disconnected from the tank.

I got it running last week and it would idle around 1k for a minute or two and then die (maybe because it wasn't warmed up?). The secondary barrels kept filling with gas, so I would always kill the fuel pump before it warmed up. It would always start, though. The float windows showed fuel 1/3 of the way full.

I whacked the top of the carb with the plastic end of a screwdriver (as I was told the needles may be sticking). That fixed the flooding barrels. I also then tinkered with the idle mix screw (probably shouldn't have) since I noticed that it felt extremely loose. I screwed it in, then backed it out 3 turns...still feels really loose. Either way, the flooding barrels stopped flooding.

BUT.

Now it wont start. Both floats sit at 1/2 full and it's not pouring fuel into the secondaries anymore ... but It's also not starting anymore.

I pulled the plugs, they were wet. I crank the motor w/o leading plugs, mist comes like like it usually does as well as the normal loud psst, psst, psst sounds. I cranked the engine with the each spark plug grounded to the strut tower, one at a time, and all 4 plugs and wires are sparking. The batt is new and it cranks hard. I don't get it! It was just running last week!

I can get it started if I send a couple capfuls of seafoam down the carb or a ton of carb cleaner. It will run for 2-5 seconds like this and then die... regardless of what I'm doing with the throttle. I can keep it running if I continually spray carb cleaner down the primaries, though.

If the engine is idling, would I be able to see fuel coming out of the jets with my naked eye? Could the fact that I need carb cleaner to keep it running mean it's not getting fuel now?

The vent solenoid is plugged in. I have capped all the little vacuum hose connectors with proper plugs and zip ties

The current set up of fuel flow is:

Tank full of premix -> cheap $3 new filter -> Holley Blue pump -> Fuel pressure regulator, set at 2psi -> stock rebuilt Nikki which IS deadheaded and has the vent solenoid powered by (+) 12v -> GSL-SE 13B motor -> Racing beat headers.

Any suggestions?

dre_2ooo

No one has any ideas? I did verify the accelerator pump is working (shoots 2 streams of fuel down the primaries).

You think placing a gas soaked rag over the carb and cranking the motor will help get more fuel in there? I think that if I do that and it starts, I'll know for sure there is a fuel delivery issue.

At this point, I can't tell if there is too much or too little fuel. Because I know I have spark because I tested each plug and respective wire. I know I have compression because it will run on seafoam/carb cleaner. It's the air/fuel ratio that isn't right. ... right?

DivinDriver

iTrader: (15)

Sounds to me like you have inadequate fuel, if it will run by "enriching" the fuel with carb cleaner/seafoam.

2 PSI is below spec, but if you're trying to set it just from the marks on the FPR, you don't really know your pressure anyway. You need an accurate low-pressure fuel gauge & a pressure of 3.7 to 4.7 per the FSM.

dre_2ooo

I agree. It seems like that's the problem. Especially since, sometimes, I'll pull the plugs and crank it and NO mist comes out.

I did use the marks on the FPR to reg the fuel. I set it to 2 because i know it could probably fluctuate from 1-4 like that. But to idle, I'd think 2 is sufficient. Especially since the floats are 1/2 full. With fuel in the floats, it'll even run without any fuel pump until the floats empty out, right?

I also wonder if I have a ginormous vacuum leak somewhere and there is WAY too much air getting in...

j9fd3s

iTrader: (3)

second to last time i had a nikki that wouldn't meter fuel, it turned out to be a big vacuum leak. vacuum leak = no vacuum signal = no fuel falling from the carb

the last time it was a sterling, and i have no idea why it didnt work, all the passages were clear, etc etc, i ended up changing the metering block with another one, and that fixed it

dre_2ooo

How would I test for a big vac leak?

DivinDriver

iTrader: (15)

If the car won't run, it's harder. Visual inspection, mostly, or by ear with someone else cranking.

j9fd3s

iTrader: (3)

i found mine by taking it apart, we could get mine to run, pushing it, it would run over 2000rpms, enough to see that the carb wasn't working right, then i rebuilt the carb (twice), and then had to look elsewhere. the sterling car, ran fine with the stock carb, swap sterling and rx3 intake, car run like poop, swap stock carb, car run great, rebuild sterling, car still run like poop, rebuild the other sterling, car runs...

i looked in the other thread, and if you still have the ACV on the intake that could totally be it, on mine the air pump came apart, and the broken pieces jammed the valve

dre_2ooo

The ACV is on the intake, but doesn't that just run only if the air pump is connected? I know the one end blows air to the cat, so that cant be it. The other end is uncapped (huge tube) and i believe that's just to recieve air from the pump. I could maybe get some detailed pics of it up here in a while.

ALSO, I forgot to mention, after it runs for a few seconds on seafoam/cleaner, it smokes alot (normal), BUT, exhaust smoke is also coming from the engine bay... I can't seem to tell where it's coming from. I doubt it's the headers, but it seems like like it's coming from the middle/passenger side of the engine.

j9fd3s

iTrader: (3)

the ACV's anti backfire valves go to the intake manifold... also on the stock setup the ACV air goes to the exhaust ports on the engine

theNeanderthol

iTrader: (1)

Wow dre 2000. Your problem mirrors mine exactly. EXACTLY. Weird. Mine even ran when the carb was flooding and it quit running after I fixed the rebuilt carb flooding issues. I'm gonna be working on it tomorrow. If I come up with a solution, I'll post here and let you know what I did.

theNeanderthol

iTrader: (1)

no luck today for me i'll try again tomorrow and report just curious, have you tried looking at the timing? maybe changing the spark plugs? When i got my car, the previous owner did the 2nd gen coil mod but he did it on the trailing ignitor and adjusted the timing weird to make it work. So the timing was pretty weird. Just a thought

dre_2ooo

Well the engine ran 1 month ago when there was a holley 900cfm carb on it. So I'm sure the timing is right. I checked all plugs and wires and they're all sparking.

theNeanderthol

iTrader: (1)

yeah oddly enough mine ran when I bought it too, even with the weird timing.

theNeanderthol

iTrader: (1)

Woo hoo! Got it going. Here is what I did for mine. I used the flywheel trick to get timing set.
https://www.rx7club.com/1st-gen-archive-71/engine-how-do-i-find-tdc-my-engine-862222/

Then I changed the plugs. I adjusted the carb per sterling to get the car started and I used a bit of starting fluid (aka ether)

I know this seems weird, since both mine and yours ran with the plugs it had in it, and the timing it had before, but it worked for me. I think I must have pulled the plugs and cleaned them and dried them and cranked it without plugs at least 20 times with no luck.

But the new plugs did it.

And I also followed sterling's instructions on setting idle afterwards. Before I cranked it I turned the IFA screw 1 1/2 turns out per sterling's instructions.

But I really think the key ingredient for me was the new plugs.

jinxed4dub

iTrader: (7)

It had a 900CFM carb? Thats freekin huge. are you sure you have a stock ported engine? I'd also look for vacume leaks. I had this same problem but it was my accelerater pump was busted.

dre_2ooo

Yeah I'm going to try looking for a vac leak and I have plugs on order that'll be here tomorrow. I just haven't had much time to really work on it these last couple weeks.

dre_2ooo

FINALLY GOT IT RUNNING!

I decided to just do a bunch of stuff and cross my fingers. First, I took a pipe cutter and made a fresh cut on the aluminum fuel return line and hooked that up to the carburetor. I then had to drop the tank and run a return line to it. I also replaced the supply line and capped the 3rd one (it was previously run back into the return one ???).

I double checked for vacuum leaks, didn't find any. I took off the accelerator pump nozzle and ran a guitar string through it just to make sure it wasn't partially clogged.

I put in all new NGK spark plugs. I poured an ounce of oil down the carb to help build compression (just in case).

I cranked it over....no start. I sprayed a some carb cleaner down the primaries....cranked, started, ran, ...kept running! It held idle around 1250RPMs and stayed there all by itself . I moved it around the driveway (don't have it insured yet), revved it up a few times, parked it, let it warm up, then shut it down.

I haven't tried it again, but I'm just very happy it can just run on gasoline again! Now there's just gonna be some tuning things I'm sure, but the biggest part is over!

jinxed4dub

iTrader: (7)

good to hear