240260280z

- lower fuel pressure (change pump from high pressure to low pressure) -regulate fuel pressure to ~4 psi - Install fuel cut-off safety mechanism Remove -manifold - efi components

A back fire in the intake will slam the flap shut and could damage it. An escape path for the gases is through the AFM bypass passage for setting idle a/f mix.I guess that was not enough so the bypass valve is needed. It only comes into play when the plugs are wired wrong and fuel is ignited in the cylinder/runner when the intake valve is open. Sorry to read the AFM adjustment did not do it. It seemed promising. An intermittent bcdd problem or a wiring problem could be the issue.

Your plugs have interesting bands on the ground straps. It may have to do with timing. I found this on the net so I am not sure how accurate it is however do some searches on what 280z EFI plugs should look like and also double check your timing.

The plug wire order should be like this: Plug 1 is at the front of the motor near the fan, plug 6 is at the windshield. Your battery is probably weak/old and trying to start so many times with the cold most likely drained it. If the voltage is 12.0V it is dead,if the voltage is 12.8V it is fully charged. The car probably backfired because of wrong plug order. Check against the diagram above....however sometimes past owners mess up the distributor alignment by 180 degress so instead of 1-5-3-6-3-4 in the photo above, you need to go 6-3-4-1-5-3. [ Put the real wire to plug 6 where it shows plug 1 in the photo and so on]

yeah! You got it. I'll ring you now.

Racebird, I am so glad to read your post and to know the crazy calibration tests I did many years ago are helping others! Thanks for your data too above.... good stuff in it for the Z community!

My money is there too.

the CO may have nailed it. A quick way to check would be to "finger the AFM" upon cold start. If you rotate the AFM away from the stop, it will add more fuel but not air. If it is a lean condition then adding more fuel should bring your idle up. Unfortunately AFM's usually age and add too much fuel due to a weaker spring. To clarify the BCCD tests above, what I meant was to do the cold morning start then hit the brakes if you don't normally do this to see if there is a difference but alternatively if you did hold the brake on start, then don't do it and see what happens... sort of a probing... but I think I now recall the bccd may be controlled by vacuum and electricity.

Was this their web site: before: http://webcache.googleusercontent.com/search?q=cache:0zHCmfQm2jsJ:www.designproductsracing.com/driveline.html+http://www.designproductsracing.com/driveline.html&cd=1&hl=en&ct=clnk&gl=ca now: http://www.designproductsracing.com/driveline.html

Wow Jim nailed it. The system does drone horribly and the common solution is a glass pack installed in the transmission tunnel.

Do you hit the brake pedal when you start the car? I am wondering if it is the BCCD? We seem to have ruled out the main items. Thought Review: The only way to change engine RPM that I know of is: timing and air (assume fuel would bog it out for now) If we rule out timing (for now) then the only devices/adjusters for getting more air into the manifold are: 1. Accelerator pedal and linkage to throttle valve 2. Throttle valve stop screw 3. Idle speed adjustment screw in throttle body 4. AAR 5. BCCD 6. leaks 7. Dash pot hysteresis 8. Drive line drag A sticking AFM flap could also limit air flow but it is not likely given your blip test which would kick it in the pants. So we are left with BCCD,drag and leaks since you checked everything else. If we rule out drag and leaks then BCCD is the one. Next time you start,do not hit brake, or hit brake or punch brake (you know what I mean). Se if it affects rpm. Aslo reach under BCCD and turn the adjustment to see if it makes a difference. I am grasping at straws. Philip

To check the linkage you could also blip-stab the throttle for 1/2 second when starting to see if the rpm's rise on release (as opposed to the 10-20 second pressing mentioned above).

The car dying with the TVS was a guess. The fact it did change most likely indicates it was working. You can check the contacts visually by pulling the cover and you can also check them with a multimeter at the connector. Do you have the dash pot on your z? I never trouble shot one but it seems there may be something mechanical involved so it could be that or linkage. Philip

I am at a loss. Your AAR seems to be doing the job right. The initial low rpm does not make sense if the AAR is open (as verified) unless at the same time your regular air passage over the throttle valve is somehow closed more than it is supposed to when cold and after the car sits for a long time. I am guessing this may be the situation. You can take off the throttle body and clean it with throttle body cleaner and check for proper functioning and set the correct stops as well as inspecting it for wear. Also you can check the linkage to the accelerator pedal. The only other electrical check I can think of for you to try is the Throttle Valve Sensor. It should be in the idle position at idle and causing the ECU to enrich the fuel mix more. To check: try the cold start again and when the idle is low and rough, disconnect the TVS... I am guessing the car will go lean and die.

Leon... I think I know you from the side draft forum

Dang, I bet FOX NEWS and CNN are soon to take sides on this bi-polar matter. I'll put on me Irish hat an' say fek it! ... they all work jus' fine lads. Now let's go watch the match (foot ball... super bowl)... nudge nudge wink wink wot's it like?

Perfect. AAR is ok. Let me think about it. BTW: What are your RPM's when it starts cold and after it warms up?

http://www.webercarbsdirect.com/Synchronizer_p/43-5712-0.htm http://www.innovatemotorsports.com/products/lc1.php

Rebuild kit is more satisfying, less expensive and you know the part will fit. Replacement is easier....but quality of newer parts tends to be worse than old ones and sometimes newer parts literally have corners cut and features removed besides the risk of poorer quality metals being used. Specifically for a replacement clutch master,you also have to ensure the clevis distances are set correctly. In both cases,as alluded to by CO above, you should re-seal or replace your slave and you might as well change the rubber hose to bring everything up to the same age (as in aging). Refurbishing is the best.... original part renewed to like-new. This will require thorough cleaning, inspection and re-plating with replacement of all plastic and rubber. Getting a year matched set from a junk yard or ebay, or getting a part that will work even better from a later nissan (and still fit) is the best route to go. That way you may still be able to operate the car with the other parts but take your time refurbishing the 2nd set then swap out on a sunny day.

I missed that one. Must be on at 3 AM?

Apart from race coverage (F1, 24Hrs of xxxx, etc) the only show that I don't click through is "Gearz" (the host is the nice guy with Gene Simmons hair cut). He gives a lot of useful info. Any other shows worth watching on Speed?

My mistake

Cast drums fracture nicely in junkyards

Quick and dirty check for vacuum leaks is to set your idle really low then spray carb cleaner around all fittings margins and hoses.If there is a leak, the engine will suck the carb cleaner through the leak and it will increase in idle speed. One strange problem that happened earlier this year was the casting between the egr and the intake plenum. It rotted through messing up the fuel air mix.for cylinders 5 and 6. It happened to HealeyZ on this forum Loose FI connectors, failing ignition module, problem with distributor, worn cap or rotor, bad spark plug wires, etc. can also be culprits.