Engine Speed Flctuations

[Riz]

I have a mini van 650 cc, EFI bought recently from a vehicle yard ( repossessed vehicle) , starting t van specially in t morning bit difficult, at idle, speed tends to fluctuate (increase and decrease on its own) and when engine reaches a certain tempreature runs fine. Engine stalls occassionally when t engine is hot (middle point) and starts again when cold. Checked t followings

1) Throttle body totally cleaned with a spray

2) Plugs cleaned and refitted

3) Coils ok

4) Mixed injector cleaner with petrol and ran

Followings issues noted

- Plugs somewhat black

- Engine oil very thick (Tappet cover was removed due to oil leakes and saw due to the thickness of the oil greasey like substances was all over , cleaned and refitted)

Can anyone advise me on these pls

1 - Engine Oil will it affect the speed fluctuations

2 - Engine stalls occassionally, (couldnt figure out as to why ), sometimes when a/c is switched on and starts when cold

(Can this be due to a sensor fault)

Any advise pls

[roadhog]

what s the millage on the engine. t

[Prami]

I have a mini van 650 cc, EFI bought recently from a vehicle yard ( repossessed vehicle) , starting t van specially in t morning bit difficult, at idle, speed tends to fluctuate (increase and decrease on its own) and when engine reaches a certain tempreature runs fine. Engine stalls occassionally when t engine is hot (middle point) and starts again when cold. Checked t followings

1) Throttle body totally cleaned with a spray

2) Plugs cleaned and refitted

3) Coils ok

4) Mixed injector cleaner with petrol and ran

Followings issues noted

- Plugs somewhat black

- Engine oil very thick (Tappet cover was removed due to oil leakes and saw due to the thickness of the oil greasey like substances was all over , cleaned and refitted)

Can anyone advise me on these pls

1 - Engine Oil will it affect the speed fluctuations

2 - Engine stalls occassionally, (couldnt figure out as to why ), sometimes when a/c is switched on and starts when cold

(Can this be due to a sensor fault)

Any advise pls

Better to check the millage as roadhog said.

And may be something wrong with the sensors...

[Riz]

Better to check the millage as roadhog said.

And may be something wrong with the sensors...

168,000 kms

[SadathN]

Engine stalls occassionally, (couldnt figure out as to why ), sometimes when a/c is switched on and starts when cold

(Can this be due to a sensor fault)

Hi bro

this could be due to the engine speed sensors or sometimes due to air mass meter.(what make /model of mini van?)

plugs getting black - probably overfuelling, also need to check the coolant temp sensor

first, pls check whether the sensor connections have corrosion and bad contact. probably has oxidation from long storage.

hope this helps

cheers

[Riz]

Hi bro

this could be due to the engine speed sensors or sometimes due to air mass meter.(what make /model of mini van?)

plugs getting black - probably overfuelling, also need to check the coolant temp sensor

first, pls check whether the sensor connections have corrosion and bad contact. probably has oxidation from long storage.

hope this helps

It's a Daihatsu Hijet 650 cc

[CARBON]

It's a Daihatsu Hijet 650 cc

Have you taken it to the Dihatsu agents, they maybe able to connect and check the error message.

Sounds like something to do with the idle control..

Stalling when temp increases to average level is a concern.

[Riz]

Thnks mates, shall chk all recommended actions, if any one cud advise me on as to why engine speed fluctuates (morning starts only) speed increases and decreases on its own and when engine reaches a normal tempreature runs fine.

Followings done

Throttle cleaned

Plugs cleaned

Little bit of sludge evidenet when tappet cover opended, cleaned and refitted

Engine flushed and new oil and filter changed.

Can sensors be checked at home, dont want 2 take it 2 a garage as far as i'm concerened i wud spend only $$$ for no return, my experience for this van, initially took (known garage) , fellow cleaned t plugs and wanted to replace the coil pug which costed me 6.5K , sprayed little bit of a cleaner to the throttle body(which i bought for 1.8K and ultimatley that F***** didnt use even 20% of the spray and when i went 2 buy the coil, fellow stole it and said everything was used) and charged 2K . Total labor charge including the stolen stuff Rs. 3K (approx)

Later a cold start in the morning same problem speed flutuates, so i chcked on my own , the old coil was firing properly and luckly returned the coil and got the money back , did all the cleanings and the above stuffs at home.

Any advise pls

[charitha19]

hmmm.. if its EFI check if it has a PCV value... usually this also causes eratic idle..

[Riz]

Engine stalling problem resolved - changed the CAM sensor

Speed fluctuations resolved - Throttle body flap even on closed position slighty gap evident , temproraly

done by covering with silicone.

Is there any other way to change only the flap rather than changing the entire throttle body.

For the entire thing costed around Rs. 8K, but totally cost around Rs. 25K just to diagnose the problem.

Van runs fine now, does around 13/14 km per litre Colombo runing.

[Prami]

Engine stalling problem resolved - changed the CAM sensor

Speed fluctuations resolved - Throttle body flap even on closed position slighty gap evident , temproraly

done by covering with silicone.

Is there any other way to change only the flap rather than changing the entire throttle body.

For the entire thing costed around Rs. 8K, but totally cost around Rs. 25K just to diagnose the problem.

Van runs fine now, does around 13/14 km per litre Colombo runing.

I think cant change the flap. Try recon Throttle body and get cleaned.

How about the fuel consumption after the repair ?