wont run unless choke on..

[skinnyz]

OK, I just put a reman Nissan L28 that I found at a dealership in my 73, and a set of new SU's from Zeddsaver. It starts and runs great, but only if the choke is pulled, and only at low rpm. I can piddle around the parking lot at work just fine, but as soon as i put some foot in the pedal, it boggs down like its starving for fuel. Before I go and start messing with the carbs, I wanted to first see what you think is the correct fuel flow volume and pressure for a set of SU's on an L28. No other mods except headers.

Thanks You!!

[beandip]

The requirements for your 280 engines are no different than the L-24 engine. Did you add oil to the dampeners in the carbs ? If not use some 10/30. Were these carbs working good on the old engine or are they new to you ? I have been running a ZX engine in my 240 for years with SUs with no issues . I am using only the electric fuel pump at the tank to supply my engine, and this was how I supplied my old L-24 also. I am using a RX-7 fuel pump and it puts out 5 psi.

You may just need to adjust the Carbs. which is likely the situation. If you havent done this before , do a search here , this has been covered in detail several times in the past.

[skinnyz]

ok thanks, I will chick and make sure the pump is working ok then turn to the carbs I guess. This is all new...both the engine and carbs are brand new. Thanks again!

[Glliw]

Just a question for you skinnyz, but what pump are you using?

[Arne]

I'm certain that ZeddSaver's carbs can not be expected to run perfectly without properly synchronizing and adjusting them - especially for a larger displacement engine (your L28) than they were designed for. Time to break out the sync tool and set the idle mixture properly. Your first step will be to drop the jets significantly so that it will run without being choked. Probably 1.5 turns from their current setting, at least. Did you do a initial mixture setting when you installed them?

[skinnyz]

still running the stock pump. As of now, I have not messed with sync'ing them at all. Just now got everything installed, car is still a rolling shell...been down for over a year now, and just wanted to make sure that with the bigger engine and different carb setup than the old flat tops, that my efforts to adjust them wasnt going to be wasted because of an insufficient fuel supply, or that the pump is just not working correctly after being down so long.

Have to admit I have been dragging my feet about getting a sync. tool, been busy at work and keeps slipping my mind. Was actually hoping that one of the guys at the dealership (I am a parts manager at a ford dealership and we just bought a nissan dealership) would have the tools to get it running right before I send it to the body shop.

I am sure there are plenty of past threads that go into detail about setting them up, but if anyone wants to enlighten me I wont complain.

thanks!

[Glliw]

If you're still running a stock 280z pump, then they put out too much pressure, yes?

[skinnyz]

running an aftermarket electric pump for now, the stock 240 pump no longer works. I am getting 6.5lbs now.

[clayton 260z]

I run at 3 lbs of preasure at 6.5 your a little high. Put a fuel regulator on and dial it down. I have mine on the return line.

Mike

[Force Fed]

Mine does the same, I think I need different needles, probably SM's. I've tried doing all kinds of adjusting but it doesn't really help, the metering just isn't right w/ stock L24 needles.

[skinnyz]

3 lbs, really? yea, i think ill take your advice and get a regulator...