[JKL3]

I'm having a problem with my '76 280-Z ,when the weather is hot .I can
only
drive it 2 to 10 miles and then it quits and won't start again for
several hours.
It's like it's getting to much gas ,but the fuel pressure is only 32 to
42 psi . I
have a new pressure regulator and my engine vacuum is fine .My engine
temperature is fine and running about 180 deg
As per a tip I received, today I 've had the time to sit in the car and
run it
for any length of time @ 2500 rpm ,my fuel pressure guage read about 30
psi and I had about 18 psi of manifold vacuum.
It ran for an hour @ 2500 mph "i was about to give it up" when it started

to misfire .The rpm dropped to 1500 ,the manifold vacuum dropped to
14 psi and the fuel gauge was showing "0" .It ran for an other 3 to 4
min.
getting progressively worse and the gauges getting lower & lower ,until
it stalled all together.I think that the tach followed the engine slowly
to a
stop .Do you have any ideas ?

 

[79-280-ZX]

Re: ENGINE STALLS ANYTIME ANYPLACE

Why did the fuel pressure drop to 0?

Put a test light / volt meter on the fuel pump. When the engine is running the fuel pump should always be on.

Check for bad connections at the Ignition Relay and the Air Flow Meter. Both of these items control the Fuel Pump.

Do you have a FSM for your car?

There is some very good information here:

http://www.zcar.com/forums/read.php?f=1&i=222735&t=222722

Wayne Monteath

 

[Matt 78Z]

Re: ENGINE STALLS ANYTIME ANYPLACE

Check your fuel filters, you should have one it the engine compartment, change it. You should also have one in between your fuel tank and fuel pump. Hopefully you have this rear filter, if not your fuel pump has a screen on the inlet that will get clogged.

What happens is as your motor runs and draws fuel, all the little rust particles from inside the gas tank get trapped on the filter and block fuel flow, if you go for a little bit say 15 minutes without running the fuel pressure drops and the rust particles actually fall back off the filter, opening up the line again or at least until they clog it again.

This is a very common problem, and it is easy to check filters.

Matt

 

[Mojos 72z]

Re: ENGINE STALLS ANYTIME ANYPLACE

Matt spelled it out pretty clearly.
I am having the same type of problem with my 72 in that periodically the car would start to hesitate and then stall. I would have to stop the car and wait for some period of time till it would start and run. I put the question out on this site and was given an answer such as Matts'. Till I can pull the tank and have it boiled out all I have needed to do is make sure the tank is always more than half full. Milwaukee

 

[Kevin 280/300TT]

I'm impressed that you can run at 2500 MPH!

I still can't get my 280 to run reliably at Mach 2.5 either (slight typo in your orig. post!)

Kevin