Technical Rough idle/misfire?

[LandyAndy]

Hope I’m not trying to teach you what you know

but.

When the ecu uses the egr valve it also closes the throttle body so that the gas from the egr is sucked through from the engine. So if you just remove the vac air pipe to the egr the throttle body will still close off the air in let to 95% closed. So if you get no problem with the electrical plug removed from the vacuum solenoid (this will give warning light on dash) and then your problem goes. It is an egr/throttle body problem.

My egr valve was stuck open, with no warning lights just poor performance and so took a far bit of diagnosis.

 

[Ducatomick1988]

@Ducatomick1988



Where I'm at..



Blank of EGR no fix



Replaced EGR control valve (pressure convertor valve) no fix



Noticed I had no vaccum on the pipe from the vaccum pipe to the control valve (Connected by a black T piece)



Saw your video and the comments so looks for a blockage, couldn't see anything, removed the pipe, clear out as much as I could, refitted, now have a vaccum to the ci trolley valve, van is running better but still not 100%, my assumption is there is still a partial blockage or a valve within the T piece has failed, I have ordered a new pipe from fiat £40 I'll let you know how I get on. Definitely worth checking if you've got a vaccum there, just pull off pipe and start teh engine you should feel it 'suck'

Oh that’s great news, fingers crossed, if this rectifies the issue this could save people in future a lot of time and money!! are you just leaving the blanking plate in the Egr valve?

What is the tube called you have bought from Fiat or do you have a link so I can just Google it so I know I’m checking the correct one for the blockage

 

[Ducatomick1988]

The black unit with the small pipes attached is the egr solenoid and allows a vacuum to pass through it, that then opens the egr. The system also alters the the air intake flap whilst it is operating, or “thinks” it is operating the egr. Disconnection of the egr vacuum solenoid is often to deal with a failed, misbehaving, throttle body, which appears to be a very common issue if you have the older style part, which was soon updated due to issues.

So would you suggest just changing out the throttle body for a newer updated on? Not sure if I have the older style part you mention but my van is a 61 plate

 

[LandyAndy]

Irrelevant to new or old throttle body, although the old one is very poo, you can’t just block the egr. You either have to unplug the vacuum solenoid, which will bring on dash warning light, or get the EGR removed from the ECU via remapping. If you do not the throttle body will close off the clean air supply, when it “thinks” it is operating the egr.

 

[LandyAndy]

This is what an EGR did to my engine, which has also cost me a new turbo. No warning lights at any time.

 

[chaaarlieee]

@Ducatomick1988 it is fixed! What a terrible fault that was. I replaced the vaccum pipe (ive qttached a picture of the pipe in question) and it has sorted it. @LandyAndy does make a very valid point co concerning the throttle body. I knew I had a vaccum issue as I had no vaccum to my egr control valve. If you do I would definitely be checking the throttle body, you can remove the air pipe and give it a good clean out (personally I would spray cleaner on a rag then clean it rather than spraying it directly into it), Also I would check the electrical connector make sure it hasn't got any green/dirty pins. Good luck!

 

[Ducatomick1988]

@Ducatomick1988 it is fixed! What a terrible fault that was. I replaced the vaccum pipe (ive qttached a picture of the pipe in question) and it has sorted it. @LandyAndy does make a very valid point co concerning the throttle body. I knew I had a vaccum issue as I had no vaccum to my egr control valve. If you do I would definitely be checking the throttle body, you can remove the air pipe and give it a good clean out (personally I would spray cleaner on a rag then clean it rather than spraying it directly into it), Also I would check the electrical connector make sure it hasn't got any green/dirty pins. Good luck!

Excellent! I had a look at mine today, I could only remove the thin black rubber tube that meats the T connector I couldn’t pry the cream ones off, did yours come off easily? I unplugged the electrical connector from the control valve and as soon as I did that it through up an engine light on the dash that now won’t go! I’ll have another go at taking the other cream vacuum pipe off tomorrow. Where did you purchase a new one from? Did you replace both or just the section that goes into the bulkhead

 

[chaaarlieee]

@Ducatomick1988 , It all comes as 1 pipe, from the brake servo (in the first picture) to a metal pipe (I'm guessing attaches to the vaccum pump) down the back of the engine. If you can get that small black pipe off the T piece, I would do take that off and start it, then put your finger on the T piece and see if you can feel a vaccum if you can then that is not your issue. I got my pipe directly from fiat commercial, was £41

 

[Ducatomick1988]

@Ducatomick1988 , It all comes as 1 pipe, from the brake servo (in the first picture) to a metal pipe (I'm guessing attaches to the vaccum pump) down the back of the engine. If you can get that small black pipe off the T piece, I would do take that off and start it, then put your finger on the T piece and see if you can feel a vaccum if you can then that is not your issue. I got my pipe directly from fiat commercial, was £41

Ah right yeah I understand what you mean. I’m going to go out and check shortly, now you’ve sorted the problem I’m determined to get mine done! Is there a specific name for the replacement pipe or don’t suppose you have a part number? Every thing I type in on Google, every part comes up except that pipe I need. There is no Fiat garages near me either which is annoying.

 

[LandyAndy]

try the part number 1350036080

 

[Ducatomick1988]

Ah right yeah I understand what you mean. I’m going to go out and check shortly, now you’ve sorted the problem I’m determined to get mine done! Is there a specific name for the replacement pipe or don’t suppose you have a part number? Every thing I type in on Google, every part comes up except that pipe I need. There is no Fiat garages near me either which is annoying.

So I’ve just quickly went and removed the black rubber pipe from the T piece and started the van up and, I can feel a slight vacuum, looks like it’s back to the drawing board. I’m taking it down to a remap place tomorrow to see if they can electronically remove the EGR then hopefully that will fix the problem and any future EGR issues!!

 

[Ducatomick1988]

try the part number 1350036080

Perfect! Thank you for that. Although i don’t think my issue is the same as chaaarlieee, I’ve just checked and there is a slight vacuum when I remove the rubber pipe from the T piece and put my finger over the hole!

 

[Anthony489]

Hi

A quick note to chaaarlieee. Looking at your photos, the brake servo vauccum reservoir looks pretty rusty. Mine was similar so I gave it a good coat of Waxoyl, as I didn't want it to get any worse and end up with a pinhole leak and having to fork out for a new one.

Items like this only seem to have thin passivation plus a quick misting of black paint, which is only OK for about 5 years. Ducato sumps seem to go the same way, you would never think a sump would rust through but they do !

 

[Ducatomick1988]

Hopefully my final update, just paid £200 and got the Egr valve electronically removed and everything seems to be fixed (touch wood ) instantly noticed a better mpg on the drive home also

 

[Crossingkeeper]

Chaaarrlieee's photos are interesting: so on the basis of expanding my knowledge base/being nosey: (delete as appropriate); the vacuum pipes are connected to what appears to be similar to inlet & outlet pipes for the heater matrix. This obviously can't be so am wondering where these large vacuum pipes lead to?

 

[Anthony489]

Hi

The second photo isn't clear, but I can confirm (having looked at my van this morning) that the pale coloured plastic pipe rises vertically, presumably from the vacuum pump on the clutch end of the engine, then goes across the bulkhead to the brake servo. Just above the bit where the pale pipe goes past the heater hoses, there is a tee junction with the smaller black hose to supply the EGR solenoid. I would guess that this tee piece has a tiny hole for the EGR feed, so that if the black hose split/drops off you don't lose all the vacuum to the servo.

 

[Crossingkeeper]

Thanks Anthony for that explanation, it all makes sense now, lol! I thought the beige plastic tube was connected to what I now realise is the bleed point for the heater matrix. Will look at my engine next time I'm in there.