i'm lost....G13A hesitation
Page 1 of 1

Author:  weallknownada [ Mon Apr 25, 2016 5:01 pm ]
Post subject:  i'm lost....G13A hesitation

Hey everybody! My grandpa's '88 Swift 1.3L with a G13A engine used to run great; but, i have been hauling thousands of pounds of roofing tile to the recycling yard with it and it has now developed a heavy hesitation during acceleration EXCEPT at wide-open throttle where it performs great after a moment or two of lag-time. Here are a couple of pictures of the carburetor which i can not identify. Any ideas where to start will be GREATLY appreciated. If i don't get this vehicle running i will have let my family down. Thanks and good luck to everybody!

DSCN3660.jpg [ 118.57 KIB | Viewed 4346 times ]
DSCN3654.jpg [ 111.92 KIB | Viewed 4346 times ]
DSCN3653.jpg [ 110.09 KIB | Viewed 4346 times ]

Author:  pacapo [ Mon Apr 25, 2016 7:25 pm ]
Post subject:  Re: i'm lost....G13A hesitation

Give us the ohm reading for the two middle pins on the rear connector.
Two connectors: one with 4 pins (front) one with 6.
Check the reading on the connector attached to the carb, NOT the wires leading to the ECM.

Author:  weallknownada [ Tue Apr 26, 2016 2:22 am ]
Post subject:  It is truly an honor good Sir

Thank you for your expertise!

Ohmeter scale at 200: 14.5 ohms

Ohmeter scale at 2000: 18 ohms

I have a feeling that is not good news. :huh:

Author:  weallknownada [ Tue Apr 26, 2016 2:42 am ]
Post subject:  ALL the truck i will EVER need! (Pictures just for FUN)

These are just three of HUNDREDS of pay-loads delivered safely and efficiently. The recycling yard is down the road only a few KM.

i always respect the vehicle and drive it softly; however, it works very-very hard for us here! (only complaining when necessary)

Thank you for your time and energy! i am reading-up on your previous posts right now; and thanking the lucky stars for your reply.

DSCN2991.jpg [ 89.06 KIB | Viewed 4329 times ]
DSCN3239.jpg [ 86.66 KIB | Viewed 4329 times ]
DSCN3448.jpg [ 83.84 KIB | Viewed 4329 times ]

Author:  pacapo [ Tue Apr 26, 2016 3:44 am ]
Post subject:  Re: i'm lost....G13A hesitation

The ohm readings do not indicate an issue, although the readings are not like mine.

Verify the fuel/air level in the middle of the sight glass:


Sight glass removed in picture above, but at least you know where to look when the engine is idling.
We don't have a good picture of a proper sight glass.
Show us yours!

If you cannot see the level, then the problem may be the float/needle valve.

The outside of your Hitachi carburetor is dirty, probably from the salt air.
Hopefully the inside is clean.

I would take a few minutes and clean the outside with a suitable chemical and a toothbrush, being careful not to get anything down the throat of the carburetor.

Author:  weallknownada [ Tue Apr 26, 2016 9:57 am ]
Post subject:  Sight-Glass Pictures

Thanks for the BIG help! i apologize, i should have cleaned it up before i asked for anybody's time.

....waiting for everything to dry off before i start her up....

meanwhile here is a sight-glass picture engine cold & off i willntake a few more if it starts up it would be very cool if it can possibly help someone else!

File comment: Not running & Cold
DSCN3793.JPG [ 95.58 KIB | Viewed 4315 times ]
File comment: a 'lil cleaner...
DSCN3763.JPG [ 85.71 KIB | Viewed 4315 times ]

Author:  weallknownada [ Tue Apr 26, 2016 11:29 am ]
Post subject:  Re: i'm lost....G13A hesitation

Got it dried-out and back together warmed it up, test drived then took the follow picture....

idles rough, like it's about to die at any second. While driving it drives good after the gas peddle is about 3/4 of the way down, usually after a sputtering hesitation. Normal driving is terrible with lots of hesitation. Shoot, i NEED the truck up-n-runnin!

Any ideas on the make 'n model of this carburetor and where to source a good re-build kit? Let me know if i can help with any other pictures others may need.

File comment: At a rough-idle & warmed-up.
DSCN3821.JPG [ 106.04 KIB | Viewed 4313 times ]

Author:  pacapo [ Tue Apr 26, 2016 10:19 pm ]
Post subject:  Re: i'm lost....G13A hesitation

Sight glass looks spot on.
Absolutely the BEST fuel/air level pictures ever posted on Teamswift.
My compliments.

Next check the secondary pot and see if it holds vacuum.
The secondary butterfly opens with vacuum.
I doubt it is your problem, but if it or the idle up actuator leaks, then you will get a lean mix as you increase throttle.

You will find some interesting reading here:

and the bowl vent solenoid check should be in that thread.

Your issue is probably the Mixture Control Solenoid


as you have ruled out almost every other possibility.

Author:  weallknownada [ Tue Apr 26, 2016 10:40 pm ]
Post subject:  Many many Thanks for your help!

i'm going to have to take the bus into 'town' to see if i can buy one of those vacuume tools. i'm too scared to drive the beast because it's about an hour plus drive to the nearest decent tool-store! Meanwhile, i would LOVE to purchase one of the MCS's regardless if that is my problem or not; and i have a funny feeling your the best person to ask about that!

Author:  weallknownada [ Tue Apr 26, 2016 10:45 pm ]
Post subject:  Hitachi or Aisan?

Almost forgot to ask... can my carburetor be identified as either Hitachi or Aisan? i have tried to compare pictures but apparantly my eyes are terrible for detailed comparisons. Thanks again!

Author:  pacapo [ Wed Apr 27, 2016 6:25 pm ]
Post subject:  Re: Hitachi or Aisan?

weallknownada wrote:
Almost forgot to ask... can my carburetor be identified as either Hitachi or Aisan? i have tried to compare pictures but apparantly my eyes are terrible for detailed comparisons. Thanks again!

Your question was answered above, but the answer can also be found at the beginning of section 4 of this manual: ... wap&page=1

Carburetors work best if used daily.
If they sit for long periods of time, the fuel may evaporate and leave residue which can clog passages.

Author:  weallknownada [ Fri Apr 29, 2016 2:20 pm ]
Post subject:  Thanks, time to do MY homework!

Just to eliminate some possiblities i have started the replacement of ALL vacuum lines with new hose, changed the spark plugs, coolant-flush, oil-change, and have ordered a new mechanical fuel pump and filter in case the problem lies in any of those areas, i am trying to narrow it down as much as possible! i will report back on my progress in case anyone else reads this in the future.

Author:  pacapo [ Fri Apr 29, 2016 9:12 pm ]
Post subject:  Re: i'm lost....G13A hesitation

I am not a gambler, but from what you describe, it would indicate a bad MCS.
(fuel/air photo eliminates the fuel pump as a problem)

Spend your money wisely. Fuel pumps and vacuum lines rarely are the problem!

What oil are you using, and what are the compression test results?

Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group