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mike_a_mechanic
mike_a_mechanic, Mitsubishi Mechanic
Category: Mitsubishi
Satisfied Customers: 51
Experience:  17 years experience as a auto mechanic, foreign and domestic.5 years running my own repair business.
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I have misfire on Delica V6 3L on no 6 cylinder. If i rev it to 5000 rmp the misfire clear

Customer Question

I have misfire on Delica V6 3L on no 6 cylinder. If i rev it to 5000 rmp the misfire clear and engine run smooth and operate normally until switched of then same story again.
Submitted: 2 years ago.
Category: Mitsubishi
Expert:  Greg replied 2 years ago.
Name is***** goal is to provide you with excellent service – if you feel you have gotten anything less, please reply back,

What malfunction codes did you have before the repairs .and have now after repairs

What year is this Van .

What was the compression readings .

Rgds Greg
Customer: replied 2 years ago.

2006 Mitsubishi Delica 3l v6

No Codes

Compression +- 200 psi on all cylinders according to Mechanic.

Expert:  Greg replied 2 years ago.
Hi Fanus .

How did he confirm cylinder 6 was misfiring .

A misfiring engine will trip a malfunction code , like a P0300 or defined cylinder like in your case P0306 .

How many miles on this engine and was the timing belt replaced at all in the past..

Greg
Customer: replied 2 years ago.

85 000 km

No 6 Plug were fouled. Also only one if take lead off that idle stay the same. Plugs were replaced in mean time. Can also be that No6 is dead and misfire on other cylinder ?

Def. No codes - 3 Diff W/Shops. Also if they try under Pajero no Codes or anything ?

Cannot confirm anything re Timing Belt.

Expert:  Greg replied 2 years ago.
Hi Fanus .

Okay good, only No.6 plug was fouled, what did the plug look like, oil deposits, wet , dry .

Greg.
Customer: replied 2 years ago.

Plug Dry but fouled. Colour same as other plugs.

Forgot to mention: The fist mechanic replaced valve lifters on No.6 as this was first suspect. Did not make any diff.

Expert:  Greg replied 2 years ago.
Check the injectors looks like this one may be sticking.

Swap the No.6 for the No.1 injector and see if the misfire moves to N0.1

Greg..
Customer: replied 2 years ago.

They tested and swapped injectors. Also the leads was swapped and replaced.

Expert:  Greg replied 2 years ago.
Did they do a injector current test to each injectorusing a injector noid light .

Please let me know all that was tested .

Greg
Customer: replied 2 years ago.

It seems they have a sort of a test bank where they connect fuel and then put elec on and check if the spray/drip etc ? I do not think they did current check or with noid ?

Expert:  Greg replied 2 years ago.
I want to know if No.6 is getting ainjection puls .as it looks like all other options are good
going from what you have told me .

Greg
Customer: replied 2 years ago.

Yes its getting pulse according to Auto Electr.

Expert:  Greg replied 2 years ago.
Do a exhaust backpressure test.

A blocked exhaust cat is only out option left as i see it at the moment .

Greg
Customer: replied 2 years ago.

We removed and checked cat also. Its clean and can see through.

Expert:  Greg replied 2 years ago.
What was the fuel pressure .

Have you done a complete drive cycle to see if all system get ready and if the check engine light comes on .

What are the fuel trims at idle and at 2500rpm

Throttle body and IAC are these two clean .

Greg
Customer: replied 2 years ago.

Wil check this tomorrow with shop that worked on car.

Add. Info: If you test exhaust with paper it goes in and out like tipical valve problem. However after you rev it to 5000 rpm and engine run smooth the paper also stable.

One vacuum pipe on top of intake manif on right hand side if you look from front also pulsating not constant vacuum ? Not sure about this.?

Expert:  Greg replied 2 years ago.
This sounds like a sticking valve ,fit a vacuum gauge to the inlet manifold and give me the reading and the needle should be steady if it flickering back and forth then you do have a valve issue .

Better have the shop do a leak down test on No.6

Greg
Customer: replied 2 years ago.

OK will do and revert back to you. What is funny that if you rev the engine and switch it quickly off and on again it start misfire again ? That is why we thought it must be an electrical problem not a valve ? This Delica is keeping a few people busy.

Expert:  Greg replied 2 years ago.
Hi Fanus .

Yes this is a good one.

This is not a GDI or is it .

Greg
Customer: replied 2 years ago.

Greg

No its not a GDI

Sorry for only now responding - was out of reception area.

Expert:  Greg replied 2 years ago.
Hi Fanus

Can you do a good drive like first highway at 40mph for 15 minutes then city driving stop and go and with switching off the engine a few times in between ,this should cover most drive cycles, then recheck for codes .

Greg
Customer: replied 2 years ago.

Greg


 


At end it was the timing belt that jumped 2 teeth. Car is running fine now. Do not know why they did not checked it earlier. Thx for advise.


 

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