Engine running rough

[Bobby4Puma]

Hello guys i need your help with an weird issue i didnt encounter so far in any car unfortunately my 3rd Puma its an utter piece of c**p so...the issues first :
When im coasting , only when the car its moving , so either the clutch its pressed or in neutral it revs by itself around 1800 rpm , either stays like this till i stop or its fluctuating dropping the revs and then goes up...this thing happen as well when im.braking....also the car doesnt feel as nippy , it feels underpowered...any ideas?
Recently ive changed the brake vacuum used( that black looking dish behind the brake pump ) and the brake vacuum hose ( not new ) i have another puma for spares .
I will go on monday to a ford garage to scan the car for problems but if u have any ideea whats causing this issue ill be gratefull cheers....
If i didnt express myself correctly feel free to ask me for more info about this issue

 

[Wild E. Coyote]

Judging by the explanation you might be having a vacuum leak somewhere that is confusing the PCM as it bypasses the MAF and PCM is trying to overcompensate all the time....

 

[Bobby4Puma]

Tnx for the rwply , i was thinking the same...i used sime brake cleaner spray to test it , it seemed it leaks on the air intake side and i put some silicone around it and test it again and it doesnt leak...do u think the brake vacuum might be damaged? I dont hear any hissing like it happened to the old one, but maybe ita not too damaged and i cannot hear it . The hose has some kind of bulb or something in the middle...what is that? Any ideeas on what to check see what its wrong? Also they cut the hose a little bit ... Its a hard hose to find and new its like 60 quids from ford only the symptoms worsen in time ...i even disconnected the battery for half an hour to reset the ecu ... It seemed at first runs better but since last night its worse

 

[Wild E. Coyote]

In the middle of the vacuum pipe is one way valve preventing the oil fumes from entering the servo and damaging it.

If hose is cut, it is leaking there for sure. Try putting some duct tape over it and see if that improves things

 

[Bobby4Puma]

Ok ill try to do that as well cheers

 

[Bobby4Puma]

I have some extra info , the revs are oscilating only when the car is coasting in neutral , clutch not engaged . While the car is stopped and idling the idle is fine, accordimg to one of my friends if it had leaks should oscilate while idling as well. Monday ill go to a Ford specialist and ill hook it up to the computer and see how it goes...this problem its so odd it drives me nuts

 

[Wild E. Coyote]

Is speedo working ok, as this might point to a faulty VSS (Behicle speed sensor)?
The other thing I would check is the clutch sensor (a switch located on the pedal telling PCM that you have depressed the clutch pedal)

 

[Bobby4Puma]

Yes speedo seems fine ... Also to be honest i feel a little bit when im.accelerating as well , and sometimes it feels underpowered and sometimes i smell petrol when i stop and get out of the car...not sure if its related... And fuel consumtion seems a little higher lime 25%

 

[Bobby4Puma]

I might be stupid but lucky ) i disconnected the battery again to reset the ecu and now the issue stopped....probably was leaking somewhere and after i aplied the sillicone i didnt reset the ecu....ill wait for a day or 2 to see if im issues free ...anyway i wanna go monday perform an error scan with a tool from ford , my odb2 reader doesnt connect to my Puma tnx for the help Coyote

 

[Wild E. Coyote]

Yes speedo seems fine ... Also to be honest i feel a little bit when im.accelerating as well , and sometimes it feels underpowered and sometimes i smell petrol when i stop and get out of the car...not sure if its related... And fuel consumtion seems a little higher lime 25%

Should have said that first: first clean up the MAF. Be careful, use ONLY brake cleaner on the wire in it, do not try touching it. Few squirts of brake cleaner, leave it for a minute and reaaply. It will clean up gradually. It should be shiney, most probably is covered in dirt and black all the way. If that doesn't help (can't hurt), the lambda probe might be acting.
WARNING: if the MAF is clogged, it WON'T throw out any code on scan. It will just supply the PCM with wrong data and the engine will be hesitant and use more fuel on average.

 

[Bobby4Puma]

Sorry i forgot to mention i cleaned the MAF and i did exactly as u said last night the car drove fine

 

[Wild E. Coyote]

Excellent. That should be it, then!

 

[Bobby4Puma]

Hopefully so....thats why i cleaned the maf at some point so i can rule it out...probably was a leak that i covered it with the sillicone ... But i could see its fixed only after i reset the ecu....ill see today how its running...cheers for the help

 

[Bobby4Puma]

Wild E unfortunately my ghost have returned i connected the computer with ford program and i got the p0135 error...the o2 heating issue...although i get theese symptoms when the car runned for a while...any ideea if the o2 sensor can cause that oscilation? I reset the ecu it runs fine for half a day then it starts again...high fuel consumption and the revs oscilating when in neutral and coasting

 

[Wild E. Coyote]

That means your lambda probe is no good, I would say...

 

[Bobby4Puma]

Ive just change it today...still doing the same crap i swear it drives me mad i feel like would torch the damn thing now my third puma its a nightmare

 

[Bobby4Puma]

Wild E new development...after i shut down the engine and open the bonnet i hear a hissing by the brake booster...after doing a little research it sounds like the check valve in the booster is bad...do u think a bad check valve can cause a vacuum leak and make the engine run bad? Brakes are fine...no hissing while braking or driving...only after i turn off the engine...

 

[Bobby4Puma]

Wild E i found the culprit was mostly my fault cause i didnt check the VSS properly , the wires inside were mushed but the speedo and mileage were fine...after i disconnected the bloody vss the engine runs smooth as it should