Fuel Problem or ECU?

[Luckless]

Hoping someone can throw up some ideas as to what is wrong with my vehicle. Have a 2002 NM Pajero with a 3.5 petrol engine. Last w/e we came home towing the boat, managed to get it home OK (thank god!) and then on Monday my better half went to use the car and said that it died. Turned the key, car coughed and spluttered for a few seconds an then could not be started again. Had noticed a bit of a whine when towing the boat on Sunday afternoon , but was not overly concerned. Figured I would have it looked at in the next week or two. Being flat out at work pre Xmas I arranged for a mobile mechanic (company name will remain unmentioned) to come to my house and fix the car for my wife. Two days and a grand later we are no closer to getting the car running and I have cracked the sads and told the guy to get on his bike >:(. So far they have replaced the timing belt and crank angle sensor and advised me that as this did not fix the problem. They determined that it was fuel related and advised me to get the fuel pump changed. I have since changed the fuel pump and have had no joy.

Now that I have finished work for the year I have been able to have a look at it myself. I am happy that there is a spark, the fuel pump appears to be running (however when I kick the ignition over I am not getting fuel up at the engine). Reading through some forums on the web I have found a suggestion that this could be a failure with the ECU. I am now scratching my head as to where to go next. My thoughts are to possibly replace the fuel filter (although I was advised that this may not improve things) or to look further at possible fault in the ECU. The mechanic that came out said that he had checked for any faults on the ECU and had not found any - but I am taking this advice with a big grain of salt.

Any suggestions that you could give would be appreciated as it is a real bugger trying to fit a family of 5 into a little Hyundai Excel - never mind the fact that the car is blocking access to the boat as well as being the tow vehicle!

[blaze]

In my opinion there is only one way to work out a problem like this and that is to work through the diagnostic procedure. Some ecu's show faults/codes on a lcd display and others require extternal test gear. Until you do this you or the mechanic are only guessing to what failure you have. You may well have one minor problem overlaying another minor problem. The diagnoses on a fuel pump needs to be tested to see if you have pressure (you may well have flow and no pressure) Here lies the problem with modern vehicles, nearly beyond theaverage backyarder or like me the mechanic that hasnt really been in the game for a few years.
cheers
blaze

[BilgeBoy]

Luckless sure sounds like a good name for this post!

Well you have done the right thing and put a post on Ausfish...So we better try and change things around for you...after all it is Christmas!

Firstly we have to establish three things...These three things haven't changed since the Model T ford and are critical before we go to the next step!

a. Fuel
b. Spark
c. Compression

Now the modern vehicle can be a little trickier but....the basics are the same. Stick a compression gauge on it to make sure you have compression. You need to see if you have pressure and flow and do you have spark! It sounds like you are happy with the spark side of things. Testing the fuel pressure will require a gauge (inline style) and you can check flow by pointing the hose into a tin!! You get the idea!

If you have these three things then all is well and can move to the next series of things to check!

Powers and Grounds!!! Pretty much the most overlooked symptom in the modern motor car. The computor needs stabel voltage...and a certain amount. So what is you battery like...are the terminals clean, have you checked the fuses, fuseable links and relays...are they all Green!!!

Next is Earths....Have a good look around the engine and engine bay....you will find heaps of these little suckers....are they clean.

Next is Injectors!! Are they pulsing...you can buy a little LED tester at spare part shops that you clip into the injector connector...If the LED pulses....The ECU is asking the injectors to open!! If you don't get pulses then you may have ECU issues!! Maybe!!

A quick ECU test (and this is by no means fool proof) is to try and cause a fault in the engine management system and then see if it logs the fault...if it doesn't log the fault....it is fair to say the ECU is buggered. You could try disconnecting the throttle position sensor or the crank angle sensor and trying to start the car.

Oh just on spark...You should use a Spark tester (again you can buy these) to check if you are getting enough out of the coil.

I would have also said timing....but it sounds like your mechanic has changed the cam belt...that and a compression test will usually show a miss timed cam by low compression readings!

Next I would have advised you to run a self test on the ECU....But you need a scanner to connect to these suckers!! So without one... things are a little tricky...but again not impossible. Equipment is required!!!

So there are a few more things to try anyway...Let us know how you get on!

Regards

BilgeBoy

[blaze]

Hi Bilgeboy
Trying to understand this statement,

I would have also said timing....but it sounds like your mechanic has changed the cam belt...that and a compression test will usually show a miss timed cam by low compression readings!

The compression is created by the fixed swept volume being compressed into a smaller space irespective of when the valves open or the spark, sparks which is the funtion of timing via the cam belt or gears
cheers
blaze

[BilgeBoy]

Blaze mate you are correct!! I should have said timing of a more serious nature...i.e Skipped belt!! But this has been replaced the mechanic so i guess that should be OK.

Regards

BilgeBoy

[Roughasguts]

Hi Luckless, the whine you speak of could it be from the fuel tank, eg fuel pump.
How low is the fuel in your tank ? Do you always run the tank nearly dry ? I'm thinking it may of been running dry from time to time just a few seconds or so and burn't the pump out.

If there anything like a bilge pump they can pump but have no head pressure so in fact be stuffed.

It's a pitty you spent all that money unless the services where due.

[Kleyny]

Are you getting fuel to the injectors?
remove the fuel line and crank the engine you should get fuel pumping out at a great rate.If not you have a blockage.
The whine could be the pump cavatating
IMO you start with the easiest things then work up to the harder.

[Lucky_Phill]

I had a fuel pump issue ( or thought I did ) a while ago.

Long story but in the end Diesel Australia at Slacks Creek not only diagnosed the problem over the phone, but they were 100% correct and fixed the problem in a matter of hours and the costs were very reasonable. WHY, cause they knew what they were doing.... simple. These guys deal with these issues day in and day out.

Good luck............less.

Phill