Technical Hesitation when accelerating

[howardsam95]

Hi all,
Getting a weird hesitation when accelerating, it only seems to happen when half on accelerator and not when pushing down to the floor.
I have changed spark plugs this year, and HT leads last year along with spark plugs. Possible that it could be coil pack? Anything worth looking out for?
Sam

 

[a1ant]

Hi mate,

Unfortunately there are lots of things that can cause hesitation. You've made a good start by replacing the plugs and leads, that should help rule them out.

Your correct that a failing coil pack could cause a miss/hesitation under acceleration. I would expect it to miss more under heavy acceleration.

It could also be being caused by a failing lambda sensor or map sensor or temp sensor. Only way your going to be able to test these items correctly is with diagnostics software or oscilloscope / multimeter.

Do you have any other symptoms? Noticed an increase in fuel consumption? Smell of fuel from the exhaust? Not having to top up oil or coolant regularly?

Alan

 

[Ziggy122]

Is this only when the engine is cold?
Or when the engine has warmed up
Or when the engine has been on for a long time?

Ziggy

 

[howardsam95]

Does it when its hot and cold really but not all the time. Its only when im part on throttle or ive just had my foot right down and then lifted it up sometimes it jumps a bit. I also thought lambda sensor, might start having to check the sensors with multimeter etc
Sam

 

[a1ant]

Hi,

Could well be lambda, as they get older their reactions slow down, and as such they lag behind a bit in supplying fuelling information to the ECU. Best way to test a lambda is on an osciliscope. Some diagnostic software will provide that function too.

Alan

 

[howardsam95]

What wouldbi be looking for and able to test? Either with logging information from obd or with testing equipment

Sam

 

[Ziggy122]

What wouldbi be looking for and able to test? Either with logging information from obd or with testing equipment

Sam

i advise MES (multi-ecu scan)
The 1.2 8v is engine is covered in free edition

So get a cheap cable connect up and watch for the 20mins the software runs

once 20mins has passed, just close software and open it up again

Ziggy

 

[howardsam95]

I already have registered edition, but obd reader isnt working. See my other post for that haha.
Sam

 

[LukeEssex]

i have the same problem and have changed alot of stuff like the Coil packs 1 and 2, HT leads, Spark Plugs, the one lambda sensor, Cleaned the Throttle Body, Tried another ecu, Drained the petrol and i took it the fiat place near me and they said that they cant find any-think wrong with it :bang:

 

[atom0007]

Have ou checked for smooth operation of valve in throttle body?

 

[howardsam95]

Yeah whilst i was doing HG. Cleaned it all up aswell. Im currently in the process of aquiring a new used engine. Could be a little project to keep me busy and end up with nice engine. Who knows. Will monitor some things soon.

Sam