Help!!!

[Fun_in_my_z]

"It's normal for SU's to need several seconds of cranking on cold starts, especially after sitting several days."

Dave I'm not sure where you came up with this idea but...

Mine has a electric pump. I let it sit for about a month between start ups and it hits on the first try.

Just turn the key to the "on" position and wait for a few seconds pull the chokes and hit the switch you wont even hear the starter.

Bill

[Ksteve]

By the way I am running an electric pump (no mechanical), MSD coil, e-ignition, Magnecore wires, NGK plugs with .045 gap, and compression at 170-185 on all cylinders and it is still a slow starter.

[240ZX]

I'm going to agree with DaveN, as his explanation perfectly describes how my SU L28 fires up. I run only an electric fuel pump, located just in front of the fuel tank....no OEM pump on the block! I also run a Mallory Unilite distributor, MSD coil, Magna Core 8mm wires, and the standard issue plugs gapped for the extra voltage. Once it's warmed up......it fires 1st crank everytime! Another way to resolve your cranking issue is......start that baby up every day!!!

Tom

[Arne]

My two '71s are both the same as Dave and Dave. The yellow is electric pump only, the red is factory mechanical pump. Both are still running points (for now). The yellow car is only started every couple weeks, the red car seldom goes more than 5-6 days between starts. I drove the red car last night, and so it started fairly quickly this morning.

[jackwarnock]

I need some help with the same problem. Recently my 1973 Fairlady 240Z has been very difficult to start. It seems to be starved of fuel (on start up) as described earlier here. The car is fitted with 3-screw SU's, not the original flat tops. The car has the large black cannister fitted to the front right side of engine. All fuel lines and the in-line filter are new or near new. The car only has the mechanical pump fitted to the engine. There is no electrical pump fitted.

I have fitted a new distributor, coil, resistor, spark plugs and leads. Timing has been set properly and plugs set at correct gap. The air cleaner is new and clean.

I don't believe I have always had the problem quite like it is now. Maybe it has been worse since I replaced all the vent and fuel hoses associated with the fuel tank?? The fuel tank was perfectly clean when I checked it when I had it off for hose replacement.

On start up it takes many attempts to pump enough fuel into carbies (with chokes fully on). When it does first try to fire up it appears to be only firing on say 3 cylinders, until more cranking gets the engine to fire. I believe it takes far too much effort to start, but once going it runs very smoothly. The engine will fire up straight away after it has been running for awhile, but sitting overnight it is then very difficult to start again.

It appears that the fuel "drains away" whilst the car is sitting, but I have no idea what is actually happening.

The starter motor has been overhauled. I have a new battery and new battery leads. The engine turns over very strongly, but I have to crank for far too long to get the beast to start.

I believe I have provided all the basic information about the engine. Cannot think of any other relevant information that might assist you good folk to help diagnose my problem.

Any helpful advice would be most appreciated. Thank you in advance.

[hd240z]

Jack, If it seems to be firing on only 3 cylinders, then the choke on one of the carburators is probably not adjusted properly or sticking part way. Check for the cables moving both tubes on the bottom of the carbs the same amount when the choke lever is pulled. You will probably have to remove the air cleaner housing to see tubes properly. I had to clean the gunk off the outside of my tubes to get them to work freely and cold start better, but it still takes several seconds of cranking and I use two pumps, electric in the back and the stock mechanical pump.

[jackwarnock]

Hullo hd240z

Thank you for your response. You helped me focus a little more on how I use the choke(s). I have just done a start of the veicle after it has been sitting for approx 30 hours. Outside temperature 19.5 deg C (67 deg F), so not too cool. I did pull a little harder on the choke lever and it seemed I got more movement/action on the chokes than I had previously. The car started really quickly!!

Given I should check it again in a day or so and do some fine tuning on the cable/choke adjustment as well, I will see if something as simple as this has solved the problem!! I am thinking I probably wasn't using much choke at all and making it very hard for the engine to get enough fuel.

I am looking forward to the next "test" to see if this is in fact the solution to my problem.

Thanks once again for your input.

Regards, Jack