Engine problem causes heart attack !

[Datsun fan]

Hello people !

 

I've Nissan A15 engine ,rebuilt with all stock parts ( Distributor , plugs , carb ...) and 78 Amps alternator . The problem appears only when starting engine which is left for at least 24 hours and the problem becomes worse if weather is "cold" (22 Celsius or lower ) . It takes about 20-25 tries to get engine started ,the cranking process seems to be quick enough and fine , there is air and fuel entring the carb and there are sparks at the plugs ends and still the engine keeps start for a very moment then stops over and over!! Anyway I checked:

- Fuel lines for leak , Fuel pump , fuel filter is good and there is some fuel in it .

- Carb float is set correctly and it is full of fuel, no gas or air leak , Automatic choke plate seems to close almost 100% when starting and close fine gradually ( when closed I can open it with

my finger! is this normal? ) , throttle linkage cable is set fine , mixture screw is 2 turns opened and idle screw is 3/4 turn opened , Jets are : primary : 70/95 secondary :80/150 and clean , air filter and carb barrel are clean .

- Plugs are NGK BP6ES and tried BP5EP , plug gap 0.7 - 0.75 ... 1.6 Mm , the plugs seem fine and color is ideal and no sign of soot or oil on them .

- Original Nissan mechanical distributor with new wires , I tried to change/clean distributor/wires and to change timing , the same result !!!????

- I use correct type of engine oil -no oil or coolant consumption- I did compression test , I set OHV clearance using lashes :0.08" for intake and

0.1" for exhaust ( cold engine )

I use correct type of gas (8.6 Octane #) and the car (A/T) makes

240 Km/20l downtown .

 

Since I don't smell gas coming out of tail pipe during starting , I think it is Carb issue and there is something needs to be set well . Anyway it is a coolant type carb , I've another carb( NIKKI ) with 6 pins connector , I think it is electrical type so should I try to install

it ? I need to know the diffrence between bothe types .

 

I appreciate any effort to solve this haunted engine .

[datzenmike]

Your carb should have a choke on it. Take the air filter off and pump the gas. The choke plate should close like this:

http://i138.photobucket.com/albums/q251/datzenmike/carb720notlikethisLarge.jpg[/img]"]

 

It should not be open like this:http://i138.photobucket.com/albums/q251/datzenmike/carb720shouldlooklikethisLarge.jpg[/img]"]

[Datsun fan]

I checked the plate when engine is cold and found it is closed and there is still about

2mm clearance to be closed completely , I tried to adjust the plate but it seems this little clearance is a factory design so what should I do? What about electrical choke type ( NIKKI ) carb , is it better than coolant type ( HITACHI I think ) I have ?

[datzenmike]

Nissan uses electric choke heater. Sounds like it's adjusted fine.

 

Can you post some pictures of it?

Edited October 31, 2008 by datzenmike

[datsunfish]

Gotta be the timing or firing order.

[Datsun fan]

I'll try to send some pics tomorrow .

[Cuts metal like mad]

have you tried pumping the gas pedal a couple times before starting it? It's not a new car... Choked or not i've always had to do this with all of my datsuns, and other than that they run and drive perfectly fine.

[]2eDeYe]

^ Yep, standard operating procedure for old cars. Pump 3 times, start it up.