It used to be an occasional issue now its contstant, i would try driving off and all of a sudden its like the engine has no power. eventually speed will build up. Its an automatic fiat marea 1.6. I have checked oil, spark plugs and leads, they all appear fine. Plenty of fuel, 52k on the clock, doesnt have a back box, it rusted through now it just has a straight pipe. Does have a catalyic converter, any other info needed just ask, please help i am desperate, cannot afford a new car, and its my daughters birthday next week........
Technical Lack of power when accelerating....
- Thread starter apwbee
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Technical Lack of power when accelerating....
Are any warning lights showing?
Do engine revs build up normally but the car doesn't go anywhere, or does the engine feel flat.
What happens when you rev it in neutral or park?
You could try disconnecting the battery for a while, I believe the ECU will then return to standard and begin to 'relearn' how you drive etc.
Have you checked silly things like carpets bunched up under the accelerator pedal and the accelerator cable being very loose and not giving full throttle opening?
Do engine revs build up normally but the car doesn't go anywhere, or does the engine feel flat.
What happens when you rev it in neutral or park?
You could try disconnecting the battery for a while, I believe the ECU will then return to standard and begin to 'relearn' how you drive etc.
Have you checked silly things like carpets bunched up under the accelerator pedal and the accelerator cable being very loose and not giving full throttle opening?
idling as normal, carpets not bunched revs fine in neutral, when in gear revs just drop and there is no real acceleration. Limps to about 40 -50 and struggles to get much faster, again dont fancy taking it on motorway, so not sure if it would struggle to get any faster. Having been searching this for ages, sounded a bit like dodgy fuel pump. Gear box sounds fine, then again would i know if it wasnt, its an auto so i cant really tell if its struggling to change gear.
MrMigs08
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Hmm so its happening on the move, i doubt its a pump, could possibly be an injector failure 
but revving freely sounds like something else is involved.
I'd personally give the MAP a clean but thats just me, hopefully more will be along to shed light on the problem!
but revving freely sounds like something else is involved.I'd personally give the MAP a clean but thats just me, hopefully more will be along to shed light on the problem!
I may be being stupid but how do i get to the map sensor? and the pump reset switch under the driver seat, is it a simple unplug and replug? thats the only thing i can see under there that resembles a switch? also seen somet about a lambda sensor could it be that?
Noticed on the way home it wont rev above 5 - 5500, also when i thought revs where ok, upon closer inspection, they are not, the revs build incredibly slowly on acceleration, then it will drop a gear, over rev and then hop back up a gear, weird, i was climbing a slight gradient but nothing major, would usually fly up it!
MrMigs08
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Im sure it wouldnt rev at all if the cat was gone, if its collapsed normally engine suffers from i think massive back pressure and should probably stall quite easy .
I'm definately down for sensors or injectors, not much else would give this, heck when was the last time it was generally serviced? lack of a fat service can do this too!
Im on the case !
.I'm definately down for sensors or injectors, not much else would give this, heck when was the last time it was generally serviced? lack of a fat service can do this too!
Im on the case !
Just tried disconnecting the battery for about hour n half, to get it out of limp home mode, that didnt work, there isnt any warning light? last mot recommended new brake discs, if these have past point of no repair could that set limp home mode?
Firstly limp mode would not allow the engine over 3/3.5k on revs, doubt sensors as no inj' light on dash. It does sound like a pump problem, may be something as simple as a partial blockage on the pump filter.
Many years ago had very similar prob with my 155 weekend after many diagnostics,plug change,check MAF etc... etc... it turned out to be a nackered fuel pump.
Fuel pump changed and a bill £1500 all was good again.
This happened due to me having to drive over a brick in the middle of the outside lane on the motorway whilst overtaking an artic.
The brick rumbled under the car and smacked the plastic tank underneath which caused a shockwave in the tank and caused some damage to the fuel pump internals. The pump was able to deliver fuel at low revs but could not handle high pressures.
I have also had similar prob due to blowing exhaust and a dodgy VIS intake manifold, not sure if your has VIS intake system.
Brakes and disc do not affect limp mode.
If the CAT is gone you would here it rattling, the CAT is basically a pipe with honeycomb type mesh inside wich when its gone will collapse and begin to rattle or it could theoretically become blocked up. Only ever heard of this happing on Diesels tho'.
Hope this helps...
Many years ago had very similar prob with my 155 weekend after many diagnostics,plug change,check MAF etc... etc... it turned out to be a nackered fuel pump.
Fuel pump changed and a bill £1500 all was good again.
This happened due to me having to drive over a brick in the middle of the outside lane on the motorway whilst overtaking an artic.
The brick rumbled under the car and smacked the plastic tank underneath which caused a shockwave in the tank and caused some damage to the fuel pump internals. The pump was able to deliver fuel at low revs but could not handle high pressures.
I have also had similar prob due to blowing exhaust and a dodgy VIS intake manifold, not sure if your has VIS intake system.
Brakes and disc do not affect limp mode.
If the CAT is gone you would here it rattling, the CAT is basically a pipe with honeycomb type mesh inside wich when its gone will collapse and begin to rattle or it could theoretically become blocked up. Only ever heard of this happing on Diesels tho'.
Hope this helps...
Last edited:
MrMigs08
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Unfortunately, sensor or injector faults will definately not cause any sort of light illumination at all, only in total failure have i found the lights illuminate.
It could be the pump but as it is revving in neutral i'd assume its providing enough fuel and pressure to supply the correct amount of both, however because in gear its not revving properly, i'm to assume it could be several thngs.
I think that its being restricted somewhere,
Fuel
Air
Ignition
Fuel i can suggest here a start may be changing the fuel filter (if your model of pump allows it) and check your fuel lines on top of the pump itself and fuel lines to the engine,
Air, check for vacume leaks (could be at the mani, tb, anywhere) check pipes, tighten and check clips (i replaced the stock ones with jubilee) replace air filter etc.
Ignition can be spark plug tips (clean or replace) coil failure (i think this could be an option) HT corrosion, stock hts are apserlute trash, mine were soiled in corrosion and rust it was horrible, but after a decent sand down and clean up the car felt more happy, responsive, spark contact makes all the difference.
The list with these italian motor diagnostics is tricky, maybe a computer hookup could reveal more, it can be alot of money chasing the wrong thing so its worth trying to fix what you can.
As for limp mode i've not experienced this yet.
It could be the pump but as it is revving in neutral i'd assume its providing enough fuel and pressure to supply the correct amount of both, however because in gear its not revving properly, i'm to assume it could be several thngs.
I think that its being restricted somewhere,
Fuel
Air
Ignition
Fuel i can suggest here a start may be changing the fuel filter (if your model of pump allows it) and check your fuel lines on top of the pump itself and fuel lines to the engine,
Air, check for vacume leaks (could be at the mani, tb, anywhere) check pipes, tighten and check clips (i replaced the stock ones with jubilee) replace air filter etc.
Ignition can be spark plug tips (clean or replace) coil failure (i think this could be an option) HT corrosion, stock hts are apserlute trash, mine were soiled in corrosion and rust it was horrible, but after a decent sand down and clean up the car felt more happy, responsive, spark contact makes all the difference.
The list with these italian motor diagnostics is tricky, maybe a computer hookup could reveal more, it can be alot of money chasing the wrong thing so its worth trying to fix what you can.
As for limp mode i've not experienced this yet
.spongepants
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I have a 1.4 12v Bravo S and about 5-6 years ago was having huge problems with hesitation, drop in power, etc. Had it at a local mechanic and he said it could be a dirty fuel filter (changed it and problem still there). Eventually took it to FIAT dealer after it went into limp mode while doing 60mph (and had to cross 3 lanes to pull over - very scary). They did diagnostics on it and said it needed the official FIAT repair which was a tie wrap around the ECU. The ECU was popping in and out and causing the problems. Since then problem gone. You may have already fixed the problem, but it may be of someone else in the future. Cheers.
I would also check cam and crank sensors
Did you get spark plugs out and checked them one by one?
Make sure ecu is not wobling and that all connections are nice and tite.
Next time you fill up put a good quality injector cleaner with the petrol and drive it hard and if there is a blockage in fuel line somewhere that may just resolve it...
Did you get spark plugs out and checked them one by one?
Make sure ecu is not wobling and that all connections are nice and tite.
Next time you fill up put a good quality injector cleaner with the petrol and drive it hard and if there is a blockage in fuel line somewhere that may just resolve it...
is it still there after a few seconds of idling ?
mine is a 2.4TD , and after a driving a while at the same speed, it is very slow to accelerate again, shifting down doesn't cure it, however if I push the clutch, and idle it for a few seconds, it flies off afterwards... any suggestions ?
mine is a 2.4TD , and after a driving a while at the same speed, it is very slow to accelerate again, shifting down doesn't cure it, however if I push the clutch, and idle it for a few seconds, it flies off afterwards... any suggestions ?
Kheydin
Member
It sounds like your TDC sensor or Timing sensor or both of them already faulty..it is familiar issue to Fiat Marea 1.616v..injector indicator will appear at your instrument panel for timing sensor faulty but no for Tdc sensor.
