Debris in Carb

[mikeont240Z]

Hi - I'm relatively new to the z world with a 72 240Z. My problem is dirt in one carb - the one closest to firewall. I'm sure there was dirt from tank that got past / through the filter. I've read a number of threads and will probably need to start by cleaning the tank and working my way to the carbs.

A few questions: Can lines be cleaned (rather than replaced)? Is there a reason why only one carb is plugging up? Does fuel pump need to be cleaned? Any helpful hints?

Thanks, Mike

[Bruce Palmer]

So Mike in Northern Ontario, welcome.

What does this dirt look like? Color, consistancy?

Our JUST SUs dvd would be a big help in taking you thru those carbs.

What does the fuel filter look like?

Probably the first thing I'd do is take the gas line off the float bowl and douche all the dirt out, put the gas line back on and drive the car to see how fast dirt might find it's way back into the float bowl. Throw a new filter on while you're at it.

[mikeont240Z]

Hi Bruce - dirt looks like black specs. First thing I did was clean carb. Drove the car as you suggested. Dirt build up happened quickly. Cleaned it again (third time) - this time left fuel line to carb detached and let some gas into container - more tiny black specs from line. New filter arrives today but concerned that it won't fix problem - seems like a fair amount of dirt. Also ordered a second filter and thinking of installing it at the tank.

[oldhemi]

You probably want to search on rusty gas tanks!

You could have rubber lines or fuel pump deteriorating.

You can use an air compressor to blow out the metal fuel lines.

You can never have enough filters.

[Bruce Palmer]

If you put the black specs between your thumb and forefinger does it smear around like maybe degraded rubber might or is it hard and gritty? Old gas line being attacked by something in our new hotrod crappy gas would be well up on my list of suspects. Replace the rubber lines in the engine compartment, about a $4 deal and see what you have.

[mikeont240Z]

Thanks - will replace the filter and have a closer look at gas lines and black specs. I'm hoping you're both right - it makes sense that the old lines could break down. It will be interesting to see if tank is NOT the problem. I'll try to get to this by weekend and let you know results - thanks again!

[Bruce Palmer]

Again, is your filter showing anything that might be this black stuff? I find it hard to believe that if the black stuff is being replenished pretty fast after cleaning out the float bowls AND it's coming from upstream of your filter, the filter would be cluttered with the black stuff, if not clear full.

Also, in the float bowl lids inside that humpy thing is a fine wire mesh screen filter. You might check that too for crappolla.

Really curious to see the consistancy of the "stuff".... Really have to wait for the weekend? Can't take a couple of days off work just to satisfy our curiousity? Nyuck nyuck

[1 Bravo 6]

Sounds very much like a problem I had.

The filter wasclean but black specks kept appearing in the rear carby.

Installed new rubber fuel lines and haven't had the problem since.

Rick.

[mikeont240Z]

Took off the fuel filter - it was full. Black specs were hard and gritty. I changed the filter and cleaned the carb. It seems to be running fairly well. I'll have to remove and clean the tank but hoping this can wait until it's time to put the car away for winter. Am also going to replace fuel lines to carb when tank is cleaned. And, I now have two spare filters....

Thanks for all of the advice - very helpful!

[Bruce Palmer]

With this situation in mind I noticed that on Horsepower TV, just now, they were doing some re plumbing around a gas tank and replaced some rubber line with a gas line with a lining to resist degradation from our new gas. I'm thinking there is some unpublisized sculldugery going on with our current crop of fuel.......

Opinions??

[d240zx2]

I think you're right, Bruce, and here's why.

I had driven the Z to Nashville Superspeedway on Saturday to watch a bit of the autoX action and found myself low on gas. Returning to the hotel, I ventured off the freeway into Smyrna and found a station totally by accident that sold gas without methanol. It was a bit spendier than the normal ethanol mix, but WOW, what a difference it made in how the Z ran.

This stuff they're putting in our tanks is terrible! And "winter" gas isn't much, if any, better.

[Bruce Palmer]

The real kicker would be to get MPG figures one fuel to the other also.

On a trip to southern California back when Oregon still had real gas and CA didn't, my mileage suffered a 20% drop the minute I had to take on CA oxygenated crap. Oh, but for the good on the farm economy and the environment we need to burn 20% more of this stuff to get the same amount of work done. Doesn't compute in my feeble brain pan.....