Engine vibrate badly @ D

[yelsew91]

Hey guys, i have a 91' Saga Auto with 4G15P carb ..
The rpm drops to around 600~700 when i'm idling on D..then the dashboard n engine/hood would vibrate badly... but when i engage it to N ..the rpm goes up to 1k~1.1k.. then the car feels stable..
I have just changed the engine mountings few weeks back but the problem is still there..
i'm thinking its the idle rpm timing setting.. but if i set it higher.. would'nt the rpm goes higher when i'm on N?@_@...

And also one more thing, my mileage meter had just spoilt ..so i changed the speedometer..then i noticed the speedometer needle is abit unstable.. like its flickering up n down.. but if i reach speeds of 80 and above..then it'll become stable.. the previous speedometer had the same problem..
Bad installation by mech?

 

[EvolutionZ]

actually from what u described, does yr car vibrates when morning starts up only and be better when running in and hot?
how many mounting have u changed?
try change the gearbox mounting too.

 

[CyborgR]

check throttle body

 

[red mini 8 7 8]

with 4G15P carb ? ..... got throttle body meh ?

 

[yelsew91]

morning startup is normal just with abit of vibration..due to the cold engine i guess..
the vibration also comes in when the engine is warmed up and the car is on the road..
like when i come to a traffic jam while the gear is still in D..the RPM will drop to around 600~700..then the vibration starts..
when i put it to neutral then its ok.. but its kinda annoying when im in the slow-but-moving jam..

i've changed the front n rear mountings ..the side one using back old one..
sometimes during N the rpm will drop to 700+ also.. but when i press the accel pedal.. the vibration stops ..

btw, is it normal for a car to idle at gear D with the rpm of 600~700?

 

[cartoon]

Don't worry bro, it is not a big problem ^_^

Incorrect ideling - I think this is the main reason cause the engine viberate badly, you can reset it or send to the service center to do it.

Remember, the ideling when cold start, normal ideling, on aircond ideling, all setting is not the same. It is recommend to set all the ideling in one shot.

 

[yelsew91]

Ic... so it's the idle timing uhh..
hmm, how much would it roughly cost if i send it to the service center?
i think it's just about some screw tightening right since its a carb engine..

 

[cartoon]

Idling problem is not only cause by ignition timing, the angle of throttle valve open, idle air fuel mixture, this will also cause idling problem too.

Adjust this is very simple work, but problem is, most of the machanic not really know how to tune it.

 

[yelsew91]

Come to think of it..when i took out the air filter holder(the black thing to take in air) when the car is idle.. the valve was kinda like..unstable or something.. not sure whether its normal or not..

How about those mechanics in the proton service center?well, heard that they're not very reliable but they shud have a guideline about what to do to follow right?

Do recommend me a good service center around Sri Petaling..
I heard of Power Cruise Garage.. mayb i shud go n check it out..

 

[cartoon]

Hard to imagine witch valve you refer, since the carburetor of Proton is using "needle type", others carburetor like Daihatsu Aura is "throttle type"

Send back to Proton Service Center should be better.

Here is some guide-line to inspect the carburetor. (I think some of the machanic may always forget this)
1. Check vacuum line/hose: replace the leak/broken vacuum line.
2. Check vacuum line connection: correct the wrong connection.
3. Ignition timing: adjust back to original setting.
4. Reset all idling.
- Cold start idle: 1500~1800rpm
- Normal idle: 900rpm
(Try switch on head-lamp and aircond, if the engine is not stable enought, increase the the rpm to 1000rpm)
- On air-cond idle: 1300rpm~1500rpm

(Back to step number 3, until the idling is stable)
5. Clean caburetor with caburetor cleaner.

Adjust the carburetor is not really hard, you can search the internet and get the information.

 

[yelsew91]

i just noticed...is the idle rpm when the aircond on so high?won't the car be guzzling fuel....?

 

[cartoon]

The engine idling when aircond on will be higher then normal idling, air-cond compressor need engine speed to drive the compressor to work properly, if the engine speed is not fast enought to drive the compressor, you air-cond may be not cold.

No need to worry about fuel consumption of air-cond idling, you won't stop your car with engine runing about 1~half hour ^_^ If idling of air-cond is not high enought, your car may be hard to pick-up due to heavy engine load, engine will need more fuel to generate power, the fuel consumption will be more then idling with on air-cond.

Of course, the list about is a guide line, you can refer to your owner-manual to get the actual air-cond idling speed. ^_^

Don't worry, be happy ^_^

 

[yelsew91]

As advised..i went to the proton service center near my place and the guy said that they didnt have the o2 sensor to tune it...well, i will try to locate other proton service centres and try to see what i can do..

How about the flickering speedometer needle?i think its too sensitive already but even when the speed is over 40km/h also the same.. sensitive as in like..during jam.. i release the brake abit..then it will flicker like it indicates that the car is moving..

 

[skyline2m]

If u say the speedometer will not stable during low speed and become stable when reach around 80km/h and above means that ur speedometer cable need to be replaced.

 

[DickWad]

Hey bro,

My Wira 1.5(A) oso got d same problem.
Mine is fuel injection model but still exactly d same problem.

If u find d solution lemme know.
I've been driving ard wif dis problem for 1/2 a year but still no solution.

I've tried changing d TB, change engine mounting but still d problem persists.