240260280z

Well it was a shot. Another bit of data that seems to be constant is: - Fuel pressure seems to vary - This thread started with a fuel pump problem - Lean, Rich, Normal variations can be caused by intermittent Fuel pump or Fuel Pressure Regulator Some more things to consider trying: - replace the small rubber hose from the FPR to the manifold - power the fuel pump directly with 12V from a 2nd battery at rear wheel, or from long wires run to the car's battery before cold- starting. - swap out fuel pump - swap out FPR

Hi S, I think the EFI system has voltage references across known resistances to compensate for the battery fluctuations and alternator fluctuations on the bus. I know of one in the AFM on the circuit board. There are no 7805 78xx type regulators that I have seen... it appears to be all analogue pulse shaping. Probably germanium and maybe ECL too..... but that usually requires -V and +GND..... at least there are no tubes.

Well this is very elusive and it only occurs for a short time and we seem to have checked all of the directly associated components so now to explore a bit more on the outside.

Anything over 12.8V will charge the battery. The higher the voltage the more current will flow to charge the battery. 13-14V range is fine. My "grasp at straw" idea above speculates that maybe the EFI system needs a higher voltage from a warmed up car to work properly, at initial start when the voltage is lower from the alternator , maybe the EFI system does not work correctly (measure air and dispense fuel) until the engine and alternator warm up.

Another test idea: Could be weird EFI and voltage sensitivity...just a guess. - on cold morning run jumpers to your battery from another car - start the other car so that voltage to the Z is now ~13-14V - start the Z

Not sure. I thinks most have the fitting near the end of the steering column but the grease well/zerk on the passenger side is on early 240z/modded respectively.

Check you CSV as you suggested.... maybe it is dumping fuel. Either remove it or simply pull the connector to it.

Cool multimedia....I love technology....I remember my amazement in 69 when a fellow kid had a diecast fire truck that squirt water and another had one with wipers that worked...and another had headlights that worked... my 007 and bat mobiles with trailer and boat were pretty cool too. Shame there was no sound then like now.

Don't feel bad...we all are.... this is a tough one... I think your CSV idea is great however! It is an elusive gremlin for sure.

http://www.thesouthafrican.com/news/million-dollar-datsun.htm http://www.thesouthafrican.com/news/dented-datsuns-demented-dash.htm Before During After

Not sure. I can't recall what I observed years ago. When you rev the voltage may go up and in turn the fuel pump will put out more but the fpr should regulate. I am not sure what range it will regulate at under different demands.

You may have to go back to the dyno. If you up the FPR 6psi you will go a lil' richer. Tune the AFM to ~ 16 @ 3000 rpm with a light load if you want to save fuel on the highway. Then check what happens at WOT... Hopefully it will dip to 12-13 range with the TVS kicking in.

To check your FPR,disconnect the vac. line to it then run the fuel pump. It should read ~36psi with the engine off.

The ECU controls how long an injector is open (time only). The fuel pressure affects how much fuel will flow during that "open time". You can adjust the AFM or temp sensor to increase the "on time" that an injector is open but if your FPR is not working, then your system may be out of the sweet spot where it is optimized to work. I am not sure how this will affect your cold start problem. The fact your car ran better with higher fuel pressure seems to indicate it needs more fuel.

Welcome!

That is the beauty!

They are great. Not too hard to change and you do not have to do it all at once. Start with easy ones first. Get the 240z kit for a 240z and 280z kit for a 280z.

Maybe adjust dash pot and/or bcdd to try and fix the off throttle bog before warm up.

ROFLMAO I forgot about that one and the commentary. I think I was too honest.... but Vulcans can not speak untruths. Maybe if he mounted the roof on the hood it would have counterbalanced the hood on the roof. "Creeps me out!" "I like it!"

You will need the distributor and the ignition module. The rest can go: AFM Injectors TVS FPR Fuel Rail ECU Electrical Harness Dropping resistors AAR You may also need a vacuum reservoir-type device for powering the brake booster.

Actually I think Arne should have gone for the middle one as it looks like the bastard child of his white Porsche and his Z. Hell why not throw in the Ferrari 250 GTOh air ducts too.

That is ugliest Z.... even uglier than this or this

Big Brake