Starving above 4500 RPS's
 

Just something to throw out.

My 84 12a seems to be starving for fuel over 450000-5000 RPM's Its all bone stock with the nikki and full factory exaust including cats. The rats nest is still intact and i have no vac leaks.

It will run right up to the red-line in neutral but under load it wants to sputter a little and runs out of gas @ 4500-5000.

The car has 114k on it and not even a whisp of smoke some of the NY guys have seen her and can attest to how clean she is.

If anyone has an idea please let me know.


Thanks
Jay

1984 GSL Misty Blue Metallic bone stock

One shot fix: replace fuel filter.

The problem with the fuel filter on these cars is that once they get clogged, they prevent the carb bowls from getting adequate pressure to keep them full under WOT and high speed operation. As the fuel pump is running without load, the engine doesn't require that much fuel to get to redline. Under a load, the fuel demands are very high, and will require at least 4-6psi (carb) in order to supply enough fuel to keep accelerating.

The FF is located under the car on the left side, just in front of the rear axle. It usually hangs in a metal wire hanger and is held on the line with 2 hose clamps. Make sure that your replacement filter is flowing the right direction, and then get the hose clamps tight.

Reply back if that doesn't fix it - I think it will...

May be starving on "air". Mine would fall on it's nose at 5000 rpm until I went to the 14" air cleaner with a K&N filter.

"Starving above 4500 RPS's"

270,000 RPMs? Wow, you're really going for a high-rev engine! I'm happy with the 8,000 mine can do :p:












Sorry, couldn't help it

I noticed that i typed that after the post. Just shows that some of you are on the ball.

It is a R26B 4 Rotor Turbine motor that WOT hits 300,000 RPM's

Thanks for the laugh, and the help with the filter prob.

jay

ok so i replaced the fuel filter ($4.07) i love cheap parts.

and alas no better....

I was wondering if my cats may be clogged and how i go about checking them?

Tomorrow i am going to do the dizzy,plugs,wires etc.etc.

does anyone else have any ideas????

jay

Main jets may be clogged.....

These are the symptoms that I had when this happened to me...

1. Car runs fine until you pass about 80% on the throttle. Then it looses power.
2. Going at highway speeds, you can let off the gas for a few seconds and then floor it with no difference (still lags). This test shows that you are not just outrunning your fuel pump because it gives the carb a chance to "catch up" (refill the float bowls with fuel) while you are off the throttle.

If your symptoms closely match those, then it is probably time for a carb rebuild. The main jets can get some buildup on them, which restricts the flow at higher demand levels. You can get enough fuel through for easy driving, but not enough for full throttle.

Hope this helps....

If I were you, I will start with the filter in the carb itself as in JUNK IT; not the external filter. then do the above posts.

i didnt know there was a filter in the carb???

where is it???

jay

Where the fuel lines connect to the carb, there are 2 bolts on top of this "Y" or "U" shaped piece. Take off those bolts and attached to the bolts are small screens that are there as a last chance filter just in case something is missed by the main fuel filter.

tighten the screws at the top of the carb as they tend to loosen up with age'VIBRATIONS', HAD THE SAME PROBLEM AS YOU, I tightened the top plate of the carb and no more problems. That might be your problem! Jay :bigthumb:

help.............

i still have a starving problem over 4000 rpm's i did the fuel filter and checked every vac hose by hand.

the only thing i notice is that my exhaust smells very strong, not like gas but it has a strong smell ....

any ideas??????

jay

fuel pump or plugged cats.
best guess.