On a 17 year old car, I would take a guess at injectors or throttle body needs a clean. Take it to Honda for a diagnostic check-up....????

43 minutes ago, carlyai said:

If all else fails, go to Honda. 

Probably not talking about B2000..

more.

 

         not much more, but even 5000 bt is not exactly a king's ransom is it

anyway once you have replaced the plugs most likely unnecessarily, and with little change from 2000 baht what will you do next? locate and change fuel filter? more expense, and then what plug leads ? ignition coils? ECU ? etc etc all the time the price is increasing and the problem will in all likelihood remain. 

          Might be something as simple as a bare wire shorting out, and Hondas diagnostic equipment and factory trained technicians will find it a lot quicker than you can.

          A mate of mine makes a living buying and repairing malfunctioning cars from people, who thought they would have a go at fixing things themselves,  He considers amateur home mechanics as a gift from the gods, that just keeps on giving.

           You have already started off in the wrong direction by worrying about fuel octane ratings, this is obviously not your forte, I reiterate my original advice  take it to honda , it will be cheaper in the long run

         

On 7/22/2023 at 2:21 PM, ujayujay said:

Its 17 Years old.....maybe thats the Problem?

Unlikely, its a Honda

How difficuld can it be to find it out????

 

Did you change your 95 into 91 just currently? Then you know the answer already.

 

If use 95 and never had the problems before then you know already again

On 7/22/2023 at 2:18 PM, hotchilli said:

Engine "rattle" usually occurs at a higher RPM when using a low octane fuel..

Fill it with 95 and add some quality injector cleaner..

take it for a good run, push the revs/rpm through the gears  and see what happens.

I don't think this car has knock sensors. I recall form the older hondas, it was th v6 model had a knock sensor. Th OP's car just needs a good service. There are many independent honda specialist garages to use for this. Avoid the main dealer.

Theoretically, 95 should have a higher octane than 91. Both are 10% gasahol. I find my new car gets far better mileage with gasahol 95, over E20. Never compared it to 91. Gasahol 95 (orange) is 10% gasahol. Supposed to be easier on a newer engine. Would use benzine 95 (yellow) , but at 7 baht a liter more, seems too expensive. Hardly seems to matter with older cars. 

 

Does anyone know the difference between 91 and 95 here? Price is almost the same, so hard to believe there is a real difference in octane. However, bike mechanics have told me 95 is better for a bike. So, there must be some reason to use it, over 91?

Best ask here and let all the experts tell what's wrong. No sense going to a mechanic that can connect it to an engine scan tool and see if it pulls any codes. But what do I know? 

16 hours ago, spidermike007 said:

Theoretically, 95 should have a higher octane than 91. Both are 10% gasahol. I find my new car gets far better mileage with gasahol 95, over E20. Never compared it to 91. Gasahol 95 (orange) is 10% gasahol. Supposed to be easier on a newer engine. Would use benzine 95 (yellow) , but at 7 baht a liter more, seems too expensive. Hardly seems to matter with older cars. 

 

Does anyone know the difference between 91 and 95 here? Price is almost the same, so hard to believe there is a real difference in octane. However, bike mechanics have told me 95 is better for a bike. So, there must be some reason to use it, over 91?

So called mechanics here most of them make me laugh.

Manufacturers say Honda for example make engines compatible to run on E85, E20, E95, or E91.

 

It is recommended that you stick to the one fuel you can get to use on a regular basis.

That said it can be a case of where you live as to the same fuel being available.

 

The ECU sensor operating the fuel system on the engine will adjust to different fuels. 

 

 

 

 

Thankyou for all comments.

sorry I’ve been slow answering but I’ve made the possibly useful step of digging out the bill from May which I addend.

so it seems to me the smart option is to take it to Honda and check on the computer.

but it may be worthwhile taking the bill to the garage which fixed it in May and asking if he remembers the fault. Even if I then take it to Honda this would be useful info.

thanks again

@cheeryble

I think I can see a problem in that bill.

8 Honda jazz spark plugs B800, B100 each. I'd guess 'no way'...just my guess.

Trouble is the Jazz has so many sensors that all effect the computer (ECU), that without a scanner (you can buy them cheaply and use a mirror to install the unit under the dash) you are just working blindly.

Story: I usually buy a cheap car for Australian trips.

Last time I bought a Honda Jazz. Had  problem, took it to 3 service places...not fixed, so started changing the sensors, then bought a scanner. No fault codes showing up.

Replaced all sensors (except exaust), fuel filter, fuel pump, spark plugs and leads...still problem.

So did other tests and decided it was the ECU.

Bought a second hand ECU, replaced it, all great as probably no service maintenance had been done as well.

Moral [from experience] First step is to get a scanner and look at the fault codes.

My car didn't output any fault codes, because when the fault occurred the car just stopped as the ECU was faulty, no codes.

 

 

 

I went to the garage from which the bill came and told him the story.

I asked if he associated any of the items on the bill with the previous repair.

he said the ignition coil. Presumably the coils could be checked one by one to check this at no great expense

 

interesting that the Jazz has 4 coils and 8 plugs