Bloody Car!!!!!!!!!!!!!!!!!!!!!!!!!

 

I have had an intermitent misfire ever since i have had it

(4 months)

 

So far i have changed

PTU (new series)

Fuel Filter

Fuel pressure reg (and the other thingy that looks the same)

New injector connectors

New CAS connector

New air Filter

Mines ECU

Spark plugs only 6 months old only done 1500 miles PFR6B-11C

Cleaned every connector i could find

only run on optimax fuel

and get code 55

 

The car seems to run really well one minute then crap the next , did a 250 mile run a few weeks ago to Jeffs (zedworld) and it ran like a dream typical , the next day it ran like crap , again yesterday ran fine for 50 miles and this morning would not tickover , good job its not my first car

 

Any body have any ideas. getting to the point now where i do not want to drive it because of reliability :(

Can you define 'Ran like crap'? Under what situatuations/circumstances? What are the symptoms?

 

Tim

sorry should have been more discriptive

 

Well sometimes its just a gentle misfire and sometimes its quite hard misfire (car jerks) this can happen at any time and is very intermitent.

 

But this morning the car was hunting between 500-1500 rpm then just kept dying , would run erratic for 20-30 secs then die

Have you checked coolant temp sensor and wiring to it?

Yep thats nearly new aswell and so is the wiring

We are in the same boat mate,

I have the same problem.

 

Changed PTU and temp sensor, oil chage, clleaned the T/B's.

New plugs etc.

 

Have you run a conZult ?

Sounds like a dodgy MAS to me tbh. Try a spare.

 

CheerZ,

 

Andy

SMW1

After reading your post i think you could be right :(

 

Jeff did a consult for me a few weeks ago and every thing was sweet as a nut , it just sods law that day it ran really well.

Andy is there any way of testing the MAS ?????

 

the air filter i put on was a Green Filter which is quite heavy and long so used to bounce around alot but is now strapped in nice and tight , would the movement in the filter upset the MAS ????

Hmm come to think of it I think it's only happened since I changed to an induction kit.

 

Maybe I have damaged it somehow while fitting.

I will aquire a working MAS and try that.

Sounds likely that it is the MAS.

Failing that, look at the Fuel pump voltage regulator.

This went on my car & it took me months to diagnose the fault. The circuit board had dry joints on it! which caused a transistor to fry :rolleyes:

When ticking over try this. Disconnect each spark plug connector in turn. The engine should misfire but keep running. If you take off a connector and the engine dies then one of the other connectors/cylinders is dodgy. By a process of elimination you should be able to identify what cylinder(s) is at fault. This will narrow your search.

 

Alternatively check all your spark plug connectors are not cracked or coming loose by giving them a wiggle when engine running. Check if misfire improves/gets worse.

Even if this does determine the cylinder thats missing, if you've already eliminated starvation of fuel or spark.......what then?

 

I think this will infuriate you more! I would try the MAS next for sure!

 

Good luck.:D

ok so went home at lunchtime started the car ran fine for 20 mins sat in the drive, then the tickover went really lumpy up and down untill it stalled this happened 2 or 3 times, the car did not run long enough to check the injector and spark connections whilst running, although inbetween stalling i checked and they all seem fine.

 

on the last attempt put me foot on the throttle at a constant 4k for 2-3 mins, it popped about a bit then ran smooth and then ticked over fine for another 10 mins. then i had to leave to get back to work

CHANGE THE MAS!!!!!!

anybody got a MAS sensor they wanna sell or lend out before I go and spend £175 on a new one.

 

 

And if this don't sort it i'll be blaming you mr Duff ;) :p :D

LMAO ;) Andyp has a spare if you are anywhere near him - sorry andy ;)

Originally posted by shaunmac

Sounds likely that it is the MAS.

Failing that, look at the Fuel pump voltage regulator.

This went on my car & it took me months to diagnose the fault. The circuit board had dry joints on it! which caused a transistor to fry :rolleyes:

 

how does a dry joint cause a transistor to fail????

 

cant get my head around that one....

Originally posted by scoops

how does a dry joint cause a transistor to fail????

 

cant get my head around that one....

 

I think it is possible myself.

 

If the joint was actually *so dry* as to cause it to disintegrate whilst being smoked, it could concievably spill out hot rocks onto any nearby transistors and burn through them - causing them to fail.

 

Its a long shot i know.

u nutter lol

Originally posted by bagins

anybody got a MAS sensor they wanna sell or lend out before I go and spend £175 on a new one.

 

 

And if this don't sort it i'll be blaming you mr Duff ;) :p :D

 

MAC fixed his. Asked what he did.

 

Stuart

>how does a dry joint cause a transistor >to fail????

 

>cant get my head around that one....

 

There were dry joints on the cct board, in particular across one capacitor & a leg/legs of the transistor that raises the fuel pump voltage to 12V when car is first started.

 

Somehow the dry joints must have caused one of the junctions in the transistor to blow which in turn dragged down the second transistors (1 that pulls voltage up to 6-9V during driving) output intermittantly due to the dry joints on the fooked transistor making/breaking.

The voltage to the pump was registering around 1-2V when the car was playing up instead of 6-12V normal. :rolleyes:

Dry joints?!

 

I have had 3 FPCU through my hands and 2 of them have had a fried transistor, if I'm honest I can't see why we don't have more problems with this as at least one of the 2 knackered units I've got came from a car that was apparently running perfectly!

 

The transistors must generate a significant amount of heat given the heat sink on the outside of the unit.

 

 

Tim

Originally posted by andyduff

LMAO ;) Andyp has a spare if you are anywhere near him - sorry andy ;)

I think Andy was going to lend that to me when I see him on Saturday. :(

Well get yer handbag out then :D:D:D Fight! Fight! Fight! :D

sorted short term i hope , took it apart last night and sprayed it with contact cleaner as i could not actually remove the mesh without damaging it, put it back on and hey presto all is working well,

 

seems to get worse when driven in the rain (damp air) , are you supposed to oil new air filters (or is that a complete load of old bollox that i heard somewhere):confused:

 

Anyway will see how it goes but I think Mr Duff was right :rolleyes:

 

As usual thanks for your help:)