NEED HELP ASAP

[bredatto510]

Im frustrated and dont know where else to turn...

lets start with car

1971 datsun 510 L20b u67 head 200sx 5 spd r160 diff

problem--- car wont start... or it starts whenever it wants to once its warmed up starts like nothing

problem has been there ever since i got the motor rebuilt here are the specs

i did a compression test and 1 cylinder was low so i took out the motor sent it to the machine shop... it was already at 86 mm and i told the guy to put 280zx flattop pistons

he got oversized pistons 87mm so i figured the cylinder walls might have needed to be bored..whatever the crank is a stock l20b crank stock rods with arp connecting rod bolts

arp head studs... so onto the head is a u67 and i had him port match and polish the intake and exhaust... he also did a 3 angle valve job got dual titanium springs from isky.. got the 510 lift 266 duartion cam from webcamshafts

steel cam towers.. new lash pads of course double roller timing chain.. high volume oil pump sent my dual 44mm mikuni solex's to rebello racing for a full reuild..

put a 200sx matchbox electronic dizzy with a msd blaster 2 coil taylor 8.2mm wires new spark plugs..

basicly i crank it and it cranks and cranks and nothing i give it gas turn on the choke and nothing once in a while if i get lucky while i hold the throttle down as im cranking it it backfires thru the carb and sometimes it'll start real rough then like i said once i get it to start everything its fine... it runs fine i broke it in fine it doesnt go past 190 degrees i put a 10inch electric fan with a switch.. new starter forgot to mention new battery please if anybody has any idea please help me before i did the rubuild with the same carbs and everything it was really easy to start now i can rely on it ever it only works sometimes i have no idea why... i had a couple mechanics come and check it out and even an electrician come and check my wiring and said everything was fine... ive heard opinions everything for compression being to high to blacming in on the air horns so idk what im looking at if anybody is willing to try to come look for ur self im in socal let me know im hear all day every day ill even try to pay as much as i can please and thank you all

[zerow]

Wow!

I am local, but I can't break free until Thursday at the soonest. I am NOT familiar with the Mikunis at all...

What distributor are you running? Plug Gap? Sounds like the carbs are too rich, fouling the plugs. Lean the carbs up, clean off the plugs and try it again. Hopefully this can all help in the meantime. :)

 

Oh, and Welcome to Ratsun!

[bredatto510]

ill look it up how to do it i dont know much about these carbs either... if u want to come on thursday ur more than welcome just pm me and ill give u directions i greatly appreciate the advise

 

im running the matchbox dizzy and i thought it was the ignition control module to be messed up so i put one from a older chevy on the firewall and wired it up like that and it works for a little then the same thing happened

[zerow]

Okay, so, you're running a Datsun Matchbox distributor, correct?

Is the distributor properly grounded? Remove the black box and lightly sand the metal behind it, and where it attached to the body of the distributor itself. Run some heavy gauge wire from the distributor body to a good ground on the car (anywhere on the block that is accessible is a good place; also check the body ground strap for corrosion. Clean it while you've got the sandpaper out...)

 

Try all of this, as the Matchbox needs a good ground for spark. Remove the HEI Chevrolet module, it is best used with the remote blackbox distributor from the earlier Datsuns.

[bredatto510]

yea datsun matchbox dizzy... so basicly check my grounds on the box and the dizzy itself then use bigger gauge wire from the coil to the box??

[hang_510]

timing...

[zerow]

yea datsun matchbox dizzy... so basicly check my grounds on the box and the dizzy itself then use bigger gauge wire from the coil to the box??

Use a larger gauge ground wire from the block to the distributor body. The only ground that the distributor has is partially blocked by the distributor gasket. Not a good conductor of Ground. Grounding the distributor directly to the block solves this.

[bredatto510]

motor on time 10 degrees btdc without vacuum advance on... ok im i kinda get what u mean about the ground for the distributor but i dont know where to connect it to the dizzy from any pics or certain place where it goes?

[bredatto510]

there was one fuse blown so i replaced it and when i put the matchbox back on i didnt know which wire goes where... not the c and b connectors but the actual wires inside the dizzy green(negative) and red(positive) those onto the back of the matchbox i dont know which is which

[lil89ram50]

i agree... check your timing, since its backfiring...

[bredatto510]

ok so check my timing... i wish someone knew how to work with these carbs so they can at least do a ruff tune... i think it has to do witht hat dizzy not being grounded right or the matchbox not be wired right

[lil89ram50]

where are you located at? maybe some one on here can give you a hand. idk where rialto is at...

[bredatto510]

its near riverside southern california... like 45 mins away from la... ok so after i replaced the fuse i decided to try the hei ignition control module one more time this time with the new fuse in and it did that thing where it backfires thru the carb and is about to start but it didnt and my battery feels weak wow... so next thing is timing or wat??... should i put cylinder 1 and tdc then make sure the rotor is facing wire one then try it there or wat?? i dont have a timing light at the time

[banzai510(hainz)]

NEED HELP ASAP.

 

take your time. Youll get help but dont just be grabbing part and throwing it on there cause we havent anserwed back yet

 

You get spark from the coil? Pull the center wire from the distributor and place near the chassis/ start the car.

see if you get spark. if yes then make sure your spark is on correct time. Line motor up to TDC and where rotor point should be on #1 plug wire or very close.

 

If you dont get spark . You have power to the + side coil?

I assume the ballast resistor is removed. and you have the blk/wht wire to the + side coil. Sometimes people short the blk/blu wire at the +side coil as this is the START 12volts that can help aid in starting.

 

Should I assume you have the valve Rockers adjusted????? a quick ck is have a cam lobe pointing up and Rocker should wiggle slightly. so you know the valve is closing.

 

Now if you have spark and compression all you need is gas. I will assume with Mikinuis you have gas. it should fire.

Ck the jet bolk on top and make sure they are screwed in all the way. everything is tight.

 

Om my 44mm Mikuni carbs I can only start the car with the chokes ON and NO gas.also remeber the fire order is counter clockwise. 1 3 4 2 .

 

I dont know what you know so help up out with car has been running great then stoped all of a sudden or changed over time ec...or you swapped stuff and not told us.

PS when you grab a distributor from any car esp a matchbox make sure the matchbox has the timmimg pedastal with it. Otherwise the clocking can be off. Or maybe you have the dizzy wires 180 off. watch the vid

http://www.guba.com/watch/3000024223/Hainz-Datsun-L-Series-Engine-01-Timing-Tare-down-and-Rebuild

[bredatto510]

ok i have a bit more info now for u guys... so i was reading more and more and tryed what u said hainz so i checked for spark from the coil wire and nothing... i tried a different wire and nothing..then i read on how to tell if the coil is bad and i was told to ground a wire to the negative side turn the ignition to the on position then move the wire and if it sparks the coil is good... assuming this is correct my msd blaster 2 coil is good... so im guessing it has to do with the coil wiring and not anything to do with the matchbox distributor or anything else since its not even sparking out the coil... so heres what my wiring looks like... the black\white wire from engine harness im guessing from fuse box is connected to positive... the wire connected to the B side of the matchbox is connected to the positive... now there is the c side of the matchbox to the negative coil... 2 all black wires from the wiring harness to the negative coil and the black wire from the tachometer (aftermarket) to the negative side of the coil??... is that correct??

 

 

about the parts its a used msd blaster 2 i have been using for over 2 yrs now... the dizzy its reman from auto parts store for a 79 200sx new cap new rotor new wires... and as i stated the first time ever since i ot the motor rebuilt and switched from points to electronic ignition ive had this problem

[hang_510]

the dizzy its reman from auto parts store for a 79 200sx

and as i stated the first time ever since i ot the motor rebuilt and switched from points to electronic ignition ive had this problem

can you exchange it for another??? id try that as well.

 

new-reman doesnt mean it works...

[bredatto510]

true true... well shouldnt we focus on getting spark from the coil first then move onto the dizzy ?

[hang_510]

true true... well shouldnt we focus on getting spark from the coil first then move onto the dizzy ?

 

you diverted my focus...

 

never ass u me :unsure:

 

assuming this is correct my msd blaster 2 coil is good...

 

change the coil wire to the dizzy, thats the ONLY way its getting there

[bredatto510]

ok i was inspecting all the wiring from the switch to the fuse box and found a wire from the fuse box white and red that was connected to to white and red wires that was disconnected so i connected it with brand new connectors and then i check for spark at coil and it had spark so when i connected my coil wire back to the dizzy and tried my battery died lol damnit!! lol... time to borrow a battery charger or something... ill let u guys know if this works

[MicroMachinery]

lol, ain't it always the way :rolleyes:

[bredatto510]

what that maybe and hopefully one wire is the cause of all the troubles lol

[Braden]

if your dizzy is reman from auto parts store your fucked!!!!!!! a1 cardone sucks balls bro, throw it in the gutter and go buy another!!!! would hurt to check timing and or timing chain marks either!!!

[banzai510(hainz)]

then i read on how to tell if the coil is bad and i was told to ground a wire to the negative side turn the ignition to the on position then move the wire and if it sparks the coil is good... assuming this is correct my msd blaster 2 coil is good... so im guessing it has to do with the coil wiring

 

ABOVE STAEMENT

this is correct. So everytime you ground that wire it charges up the coil then take that wire off. the coil should fire. That also means you have the wires hooked up ok. The faster you do this the more sparks you get. You become the distributor.

B is pos

C is neg side coil.

Now the distributor is on/off switch so its not telling it or soemthing is grouning it out

 

I would disconnect the tach. and see what happens. Is you tack On all the time? Wire to like the ciglighter circut?

 

 

remember when using a point distributor the rotor might not be in the same place as the other if you didnt notice. So Thats why Line everything up to TDC if in dought

[bredatto510]

ok i put a new battery and still no spark from coil wire... ill try taking off the tach wire see what happens... as for the 2 black wires to the negative i did notice after removing some grease that one has a blue stripe.. should that still be on negative??

[bredatto510]

ok so i checked coil for power once i borrowed the multimeter and 12 volts with key on positive side and negative side... ran a new wire from mounting bolt of dizzy to a ground and nothing... thru out all of today it did spark twice really small and only once.. i even put an extra 12 v electronic coil i had lying around an accel one and nothing... i put cylinder 1 on tdc and the timing was right on... still nothing i put the matchbox back on and sanded the back metal a little made sure it got good ground... and nothing.... im seriously lost and if anybody can help me i would greatly appreciate it... if u have a 510 maybe i can just copy ur wiring exactly but other than that local shops charge me 75 bucks an hr to diagnose the problem and thats considering they have no experience in datsuns watsoever and its more than likely something retarted like a bad ground or something... if anyone can help me or is local... il give u my address whenever u can come or anything let me know pls