New Guy with 620. Weird Stuttering issue.

1972-1979 Datsun 620 forums. All 620-specific topics and discussion can be found here.
esabatino
Posts: 10
Joined: Thu Sep 24, 2009 9:19 pm
Car: Datsun 620 Pickup
Contact:

Post

Hello. First off, I work on Motorcycles... mostly vintage two-stroke ones, and am by no means a car mechanic. I bought this pickup and am really in love with it. 130,000 miles, Starts up every time and runs great. Unfortunately, about 1 in 10 times, it will start to stutter badly.If I give it gas, it will kill it, but if I just keep tapping the pedal, I can keep it barely running. Eventually it will die. Then if I let it sit for a good 2-3 minutes, it will usually start right up and run normally again.This is not heat related. I can drive 50 for an hour with no problems. I seems pretty random and may be a fuel delivery issue.My best instinct tells me to replace the fuel filter and clean out the carburetor.

I'm just on here asking for some advice as to a starting point.

Thanks for humoring a new guy.

-Eric Sabatinohttp://schillermoped.webs.com/


dimedriver
Posts: 34
Joined: Mon May 04, 2009 4:10 pm
Car: 71 Datsun 510

Post

Take the gas tank to a radiator shop and have them boil it out. Then get the inside recoated.

replace all rubber hoses in the fuel system. blow out the hard lines with an air compressor. double check fuel pressure. For the hitachi and weber carbs I think its around 6psi.

That should get it worked out it probably just trash clogging the fuel pickup in the gas tank.

-Dime

esabatino
Posts: 10
Joined: Thu Sep 24, 2009 9:19 pm
Car: Datsun 620 Pickup
Contact:

Post

Thanks for the reply.I cleaned out the Carb, fuel filter, and fuel pump very thoroughly.I'll check all rubber lines and blow out the hard lines.I pulled the drain plug on the gas tank and only nice clean gas came out.I noticed a few posts complaining about the Hitachi carb.Is it a piece of junk, or can I work with it.I don't want to replace it if I don't have to. This truck needs to get the best mileage possible.

User avatar
moparvwfreak
Posts: 272
Joined: Thu Mar 06, 2008 9:26 pm
Car: 1973 Datusn 620 4 spd(sold), 1973 Datsun 620 5spd, 1993 BMW 325I, various VWs and now a CB7 Accord

Post

i had a Hitachi on my 73 when i got it. i was NOT happy with the performance but all in all it was a good carb. i still have it if i need to swap back but i am a gear head so i like having power. i had some issues with it though as it was a 30+ year old carb. i went with a Weber carb and although a bit of a pain to tune it, and a little less mileage, it seems to be just as good if not better performance wise. if your looking for a driver and not something to really mess with, stick with the Hitachi. if you want a touch more performance, go Weber.

esabatino
Posts: 10
Joined: Thu Sep 24, 2009 9:19 pm
Car: Datsun 620 Pickup
Contact:

Post

Thanks!I'm glad that everyone's helping so much.

Today I drain the gas tank and blow out the gas line with my compressor.

Could this be points/condenser related? I've already installed new plugs and rotor (the cap looks really nice.)

esabatino
Posts: 10
Joined: Thu Sep 24, 2009 9:19 pm
Car: Datsun 620 Pickup
Contact:

Post

I've done everything involving the fuel system and it's still doing it.I'm going to replace points and condenser today.

User avatar
PEZi
Posts: 21113
Joined: Thu Dec 11, 2008 8:21 am
Car: Mitsubishi Lancer Evolution IX Mitsubishi Racing Edition
Location: Pikes Peak, CO
Contact:

Post

welcome to the forum man! i had the same issue for a while in my truck and it turned out to be crap fuel pumps and vac leaks...

esabatino
Posts: 10
Joined: Thu Sep 24, 2009 9:19 pm
Car: Datsun 620 Pickup
Contact:

Post

Points and Condenser replaced. Timing set and points gapped. Still the same problem... so I followed the Haynes manual step by step to clean and rebuild the carb. Now it wont start.I'm frustrated and will try more in the morning.

...there was one linkage that hooked into the auto choke that looked like a really poor design, but it matched up with the manual.

esabatino
Posts: 10
Joined: Thu Sep 24, 2009 9:19 pm
Car: Datsun 620 Pickup
Contact:

Post



Thought you all might like to see it. I love the color.

esabatino
Posts: 10
Joined: Thu Sep 24, 2009 9:19 pm
Car: Datsun 620 Pickup
Contact:

Post

Timing chain slipped by a tooth when the truck backfired. I believe the truck backfired due to a dirty carb. Set the timing with a light as well as I could and it's running nice now.

Now the fuse box is melting and all my accessories wont work.One thing after another...


Return to “Datsun 620”