hesitation

[mike larry]

I have a c180 and its suffering from hesitation.

when i drive the car localy, all i get is a bit of hesitation, very light.
if i take the car on the motorway i still get hesitationat 60mph, when i get to 80mph i am fine no hesitation, if i do 100mph the car will hesitation alot and reduce my speed back down, so i then turn the engine off then on and the speed remains.

if i stick at 80, i get no amount of hesitation.

any ideas???
engine sounds fine, no missfire

 

[carabind]

This could be anything,
1. If its a regular misfire, more likely to be ignition, if its more irregular, could be fuel related (or ignition) -
2. It may be linked to a duff sensor, worth getting an indie to run some diagnostics to save time and money in the long run.
3. On a DIY/low cost basis, I'd check that air and fuel filter clear and HT leads are all sound .
4. Also look for any airs leak around the inlet manifold gasket areas or any breather pipes going to this or the rocker cover
5. Have you let the fuel run to nearer empty? Could be a bit of debris distrubed by this, now in th4 fuel line/injection system

Out of interest, what's the milegae, and whe was the last time it was serviced?

 

[mike larry]

mileage is 160 with full service history, there is no missfire, last service feb 07, the car had been parked on empty by previous owner, but i put £30 of fuel and drove 200miles but still problem?

should i clean the injectors?

No missfire only hesitation

 

[mike larry]

the last service included:
oil filter
air filter
fuel filter
engine oil
hose clip

hope this helps with ideas

 

[carabind]

Ok, with FSH clearly looked after. Yoi could try some injection cleaner in with the fuel, it may possibly help or breakdown any residue that is acting as a blockage. If I were you I'd try double the recommended strenght as a off one, but lets see what others say before you do this!

 

[mike larry]

anyone else?

 

[kebo57]

anyone else?

Hi let's say you get hesitation 5th gear at 70 mph when you accelerate slowly,
If your in 4th gear at 70 mph do you still get hesitation when you accelerate slowly,
Same thing but different rev's

Kevin

 

[mike larry]

the car could be in any gear but it restricts it self to 3 and half thousands revs.....

 

[television]

could this be a MAF problem in the early stages of failure if it has one

 

[mike larry]

anyone else?

 

[jibcl500]

MAF!!!!!!!!!! I'd put £10 on it. Where are you in the UK?

jib

 

[wireman]

Maybe spark plugs, cheap enough to try

 

[kth286]

Mike

If you say the car limits itself to 3500 revs then the engine is in limp-home mode and you need to get your codes read by a Merc specialist.

But, you say you can do 100mph on motorway. What revs is the engine doing then - surely over 4000 revs ?????? which is not limp-home mode.

 

[Stevie A]

"Car hesitates on acceleration" is a classic worn spark plug problem from Haynes. I find it hard to say how you could diagnose hesitation at 100mph!

Change plugs and clean / change MAF probably.

 

[mike larry]

I took the car to a mechanic, who used his computer machine and connected it to the car.

He said that there was an error 12, lamda sensor?, does this seem right?, just making sure i dont have to replace anything else after?

 

[carabind]

well if it's at fault, it needs replacing ! I guess it depends how much you trust the mechanic's expertise.

 

[alexspurs61]

MAF!!!!!!!!!! I'd put £10 on it. Where are you in the UK?

jib

Yep, I don't know your car - obviously! - but those symptoms are so similar to those shown by my car that I'd say MAF is at fault.

Mine was sorted with a new pattern MAF at £80-ish from GSF.

 

[jibcl500]

Just took delivery of a new MAF for a SLK Comp, bought it from a chap on ebay £54.50 delivered to the house, took 4 mins to fit and it works perfectly.

See link

http://stores.ebay.co.uk/car-parts-place_Airflowmeters_W0QQcolZ4QQdirZ1QQfsubZ5QQftidZ2QQtZkm

jib

 

[mike larry]

i have got the part from a local parts company for £50 including vat, mechanic said £30 to install, so looks all good

thanks for all your help everyone

 

[alexspurs61]

Let us know if it works!