gremlin ridden 260Z

[DtsnFrkMx]

Hi I

[fiveNdime]

Is there oil in the SU's???? Take that little plastic nut off the very top of the carbs and make sure there is oil in them...10w 30 motor oil is what I use and is safe. Check all the linkage for binding. Take the air cleaner(s) off and make sure when you use the throttle that the piston in the carb doesn't get stuck in any position. if theres quite a few miles on the motor your probebly getting some blow by into the crank case from the cylinders due to bad rings. You may also be running too rich on fuel???? but you should know that if its running like crap or ran like crap. Does the oil smell like gas, or is it like a milky greyish color?

[DtsnFrkMx]

Sorry I mean gasoline in the motor oil the SUs have oil but thats the way they were designed no carburetor shop here can seem to know or are afraid to put they hands on my car

[DtsnFrkMx]

Hi fiveNdime sorry I forgot to thank you for the tips, I will be checking them up , yes it has some miles but the person I bought it from said that the motor was recently repaired, and I haven

[datzenmike]

Take the air filters off and look in the carb throats to check that all slides are returning to down idle position. You should be able to easily lift them with your finger to full open and when released they should drop to the bottom with a light clunk sound. The slides are moved by vacuum and are not connected to the throttle.

 

If one is sticking remove the damper assy (the thingy where you put the damper oil), remove the 3 set screws and carefully lift up and off the flat top dome containing the piston. Be careful as the metering rod is on the bottom end of the piston. Do nor remove the rod or drop or bend it!!! In practice the piston has enough clearance that it should slide smoothly up and down inside the dome. If not, carefully clean with carb cleaner, and a toothbrush, clean without scraping or removing any metal. Dry and test fit for smooth operation and assemble, refilling the damper with oil. (many use auto trans oil in winter)

 

Here's some good reading on SU in general including the Hitachi:

 

http://www.jetlink.net/~okayfine/su/sumain.html

http://www.team.net/www/morgan/tech/tuning.html

[DtsnFrkMx]

Hi datzenmike thanks for the input I

[banzai510(hainz)]

oon the older machanical style fuel pumps the diaphrame might have a hole and leak gas thru the front cover area.

But you say you have a eleltric pump so I assume you have a block off plate on the heada dn would not know how gas gets in the oil.

Mostly eleltric pupms need a fuel pres regulator unless your positive that it a low pressure pump of around 3.5 pounds.

 

If you stuck a aftermarket of the wall pump this can ruin a set of older carbs(weber,hithachi,SUs, Mikunis ect..)

[fiveNdime]

Yep. I have a cheap schucks regulator on mine and its ran forever.

 

A far cry, but maybe if theres no regulator for pressure its forcing fuel into the intake and into cylinders......BUT you would think it would fowl plugs or run like crap and or be hard to start....which makes a point

 

How does it start when its cold and when its hot???

[datzenmike]

I also suspects it passing gas to the oil

[DtsnFrkMx]

Hi guys thanks or all the input i