SportBikeMike

Well about a month a go my 240Z dropped a driveshaft...and scared the living daylights out of me....but I've since had the driveshaft replaced and she's been running GREAT.

However, this morning I was cruising around. just shifted into 2nd, and I heard a popping noise from the rear, and suddenly hardly any power at all. This car was still drivable to get home but it felt like hardly any power was getting to the wheels.....and also alot of noise coming from that area.

Geez, just when I thought I had the car runnin good and could concentrate on the body/paint...something else happens. Does it ever end?

Anyway, obviously sounds like some kind of differential problem. Anyone else have this happen before or might know what the exact problem might be?

NismoPick

Put it up in the air, get under the car, and take a look.

Did you try to coast in neutral? Did it feel ok then?

SportBikeMike

I don't know...been out on the bike all day, haven't driven it since but I'll check. A buddy of mine said its more likely the clutch or driveshaft (again) because if it was the differential, it wouldn't be drivable at all.....but then again he's been wrong before....

SpeciallySpiked

i agree that it could be the diff and it could be grinding it's way to nothing pretty soon.

Similar situation happened to my remote control car ( i know... I know... not a real car but still) It started losing power then just lost it all.

SportBikeMike

Just looked underneath and it looks like the U joint on the right axle popped loose. At least this shouldn't be too expensive to fix.....I hope

BoulderZ

Just replaced all four u-joints on my '78. A u-joint is not expensive, and thejob is pretty easy. I think the nice ones I got were something like $40/$50 each. The problem is doing all four, now it's a $200 parts bill. I wouldn't replace just one unless you're really, really tight on cash. By tight on cash I mean "grocery shopping at the gas station convenience store so you can use the gas credit card". Because if one went, the other three are just waiting to fail on you and make you walk home very soon.
good luck,
Dave

SportBikeMike

Thanks for the advice Boulder....I might go ahead and have them replace all four. I've pretty much had my fill of being stranded lately....

SportBikeMike

Well, my prognosis was incorrect...this explains why I'm an accountant, not a mechanic. They said there was nothing wrong with the U joints but that the problem is probably the carburetor since the car is getting next to no power. I think I'm gonna go ahead and swap in the '70-'72 carburetors and get rid of this crap '73 carburetors like every other '73 (& '74) Z owner....

NismoPick

Yikes...

SportBikeMike

^^I hear ya! This probably end up costing me over a grand all told.

On the bright side, it will greatly increase the drivability of the car and increase the value.

SportBikeMike

Well I just went and picked-up the car and she drove great, like nothing ever happened. All the shop did was grease the joints and didn't even charge me anything.....and suddenly the carburetor is working fine!....well, for now Must have just got a grain of sand or something in it....who knows with these things.....

SportBikeMike

Well, that didn't take long. Took her for a spin and started running like crap again w/ very little power. But after doing a lil research, I realized my car does have the early '70-'72 carbs, the round tops as opposed to the flat tops (shows ya how much I know about carbs....). So I don't thank its the carbs afterall. The way the car runs good on and off, I'm thinking it has something to do with the fuel lines or maybe the fuel pump or fuel filter. My car has the old mechanical fuel pump.....thinkin about getting the electronic fuel pump and a new fuel filter and see if that improves things. Who knows? This is all a learning experience for me...

Darrel

The '73 does have an electric fuel pump as well. It is in the back neat the tank. If it is still stock it has a filter inside the pump. The end twists off and the cartridge filter can come out.

My '73 had been sitting 14 yrs and had a lot of varnish in the tank. Before I dropped the tank and cleaned it out, I replaced the filter inside the pump and also put a another filter between the tank and pump.

You can see the filter and you can barely see the black bracket the electric pump bolts to in this pic.

SportBikeMike

Yeah that could be something to look into. Who knows how old those filters are. Hopefully, it is something relatively cheap like that. I'll look at the fuel pump tonite.

SportBikeMike

Damn Haynes Manual! According to this manual, only the 260Z has the electric fuel pump down by the gas tank.....but after seeing Darrel's pic and looking under my car, I've seen otherwise.

Anyway, mine is old and nasty and I think might be the root of the problems. According to the MSA catalog, the stock electric fuel pump for a '73 240Z costs $268, but I noticed you can actually buy the Holley Premium fuel pump for less than half the price ($125) and it looks like higher quality than stock...anyone familiar with these fuel pumps?

Darrel

Before you put money into buying a new pump, Take the old one apart and replace the filter. If it doesn't pump, hook up wires to a battery and push on the little button inside the pump.

Mine didn't work at first, until I loosened the pump. Take it completely off the car, clean it and replace filter.