Hi all,

I have had my laptop connected to my car's ecu (Ford Fiesta 2001 1.25 Zetec S) as i have been having a few issues over the last week.

I have no fault codes but the Lambda Sensors are reading the following.

I have managed to export some log files from my laptop ODB software reader and here is the results. Looks like Sen 1 is reading ok which is my thought or if anyone can put me right on this as Sen 2 shows nothing like Sen 1.

Readings are taken while the engine was upto temp and while the car was idling. Is it me or is sensor 2 not reading correct or a fault.

Sensor 1 (Voltage)


Sensor 2 (Voltage)


Sensor 1 (Short Term Fuel Trim)


Sensor 2 (Short Term Fuel Trim)


Engine Stats

 

Not too much wrong with the car. At least not with the Oxygen sensors.
Sensor 2 (behind the cat) is supposed to be high - above 0.6 Volt.
If it showed the same pattern as sensor 1, the cat is not working (defective/empty).
The fuel trim is only used for sensor 1, not for sensor 2.
The Long Term Fuel Trim indicates that in general the mixture is a bit weak (8%).

See this description about Oxygen sensors and checking the cat:
http://www.picoauto.com/tutorials/cat-efficiency.html

What are the problems? And the symptoms?

 

When i put my foot down on the gas the car seems to hesitate and judder a little before driving ok.

I have changed the following but still getting the issue.

Coil Pack
Leads
Spark Plugs
Air Filter
Fuel Filter
Oil Filter
New Oil

Have also cleaned the throttle body as well

I have no fault codes on my diag software on my laptop and no stored codes after i have the issue.

Chris

 

Take the car for a test drive.
Check if the Long Term Fuel trim goes up significantly when under load.
It sounds like a lack of fuel.

The only slight problem I can see is an engine temperature of 103 degrees Celsius (217 F).
That may be a little bit high for a car of this model year.
Check what it is on the test drive.

 

Hi,

I have just done a 5 min test drive in the car and here is the long term fuel graph from the drive. During this drive i did put my foot down a bit and the car held back for a few sec and judderd a bit and then was ok.



With regards to the temp gauge the car has never reported overheating and the temp gauge shows in the correct place as per the ford manual.

Many Thanks
Chris

 

Have you or can you check fuel pressure in case pump is getting weak or you have a restriction in the fuel system?

2001 (if 2001 shape) doesn't have a MAF IIRC so that's one less thing to try. TMAP sensor?

Can you confirm which shape Fiesta you have?

 

I will check in the morning if the ODB software reports fuel pressure if not how do i go about getting this checked?


I thought the 2001 Zetec S has a MAF but i could be wrong?

Could it be the new fuel filter that i fitted over a month back.

 

You will need to plumb a gauge into the fuel rail to measure the fuel pressure.

If fuel filter was correctly fitted (flow arrow towards engine) that should be fine.

Some Fiestas of that age have MAF sensor, some are on TMAP, depends which you have.

 

The fuel filter fits side ways on the car at the back and the old one had no arrow on it so i tried to follow the fuel lines and fit correct. If i look under the car from the pass side the arrow on the fuel filter points towards the drivers side (if anyone can confirm this is correct)

Is the fuel rail easy to get to?

Chris

 

Fuel rail is under the airbox.

This like the filter on yours?

 

Yes the fuel filter is like that.

 

I have an ecu reader for the car that connects to my laptop. It says no stored or active faults and the engine management is not on

 

You definitely have a fuel starvation problem if the long term fuel trim goes up to 30%.
Fuel filter blocked, pump blocked or bad.
Check you map-signal at wot. Should be close to 1 bar (14.5 psi).
You can even check this signal with the engine off - also 14.5 psi.

You don't have a MAF-sensor. There's no air mass pid (g/s).
You do have "Inlet manifold Absolule pressure" - therefor you have a map-sensor.

 

Hi

Could you tell me if i am correct if the long term graph hits 30% when drving the car then its reporting fuel starvation someware?

I did install a cheap non ford fuel filter over a month ago when i did a service as the owner of the car before me had not had it changed for a while and it was in a bad way. Do you suggest i change the fuel filter for a ford one.

Not sure what you mean by 'Check you map-signal at wot. Should be close to 1 bar (14.5 psi).You can even check this signal with the engine off - also 14.5 psi' Could you explain what this is?

Chris

 

That will teach me to read the thread and images properly.

OK - ECU gets one of it's load inputs from the TMAP sensor (temperature,manifold,absolute,pressure) ,which detects change of vacuum/pressure and air charge temperature in the intake so the ECU can calculate load and thus control fuelling and spark.

14.5psi is 1 bar absolute = atmospheric pressure (the air we breath). Which as Oldford posted can be checked with engine off key on. Also on WOT (wide open throttle) there will be no 'vacuum' on the intake so the manifold pressure should read approx. atmospheric pressure.

 

Sorry to sound thick but how do I get the reading. One of the image. Above shows manifold pressure. Is this the reading.

 

Yes, that's it.

 

Maybe. I normally would expect a DTC (trouble code) set, yes.
But the trouble code could be a code set in service 7 (trouble codes from last drive) and not yet in service 3. I don't know if your tester can read both services.
Also, I don't know what the exact limit is (30%, or maybe 35%). And then the next question is how long (milli seconds, seconds) must the Long term fuel trim be at the limit before the code is set. So, it's possible that you don't get a DTC yet.

As GVK already answered, the manifold pressure is in your data list and called "Inlet manifold Absolule pressure".

I would change the fuel filter for an original Ford one. That shouldn't cost that much.
Check whether it's dirty or not and then try again.

 

Hi

My DTC code software does show current active codes and stored codes from last drive but there is none so as you say the fault code might not have been triggered yet.

So my pressure above for the manifold shows 4.5psi. Should that read 14.5psi as gvk stated with the engine off and on.

Getting a genuine ford filter tommrow.

Chris

 

So as my screen capture shows above I have 0.3 bar which is not good is it

 

Check it with key on engine off, it should read atmospheric pressure. At full throttle when driving it should show pretty much atmos. pressure. At idle it should have a steady reading and it should change value as you apply revs from idle.

You could try disconnecting the TMAP and it should run well on the (substituted) TPS values (it will set an open circuit TMAP code which you can clear)

You could of course remove the TMAP sensor and see if it's contaminated with oil deposits.

 

Cheers GVK

Will check this in the morning before work and post the readings later on in the day for you to view.

Could you tell me where the TMAP sensor is located (Is this the same as the MAS Sensor? as i cannot find a guide about where the TMAP is located on the 1.25 zetec s

I have already cleaned the throttle body which was gung up with oil. Is it located anyware near the throttle body. If it is dirty is it ok to clean?

Picking up fuel filter in the morning once ford open.

Chris

 

If your's is last of the old (Fiesta 1995>) shape it's inside the air filter box, under the air filter element. I had to look on Ford ETIS to find it's location, as I've never had any issues with that sensor on those cars.

If the 'next' shape it's next to the throttle body.

Best stuff to clean it is isopropyl alcohol which you can get in aerosol from Maplins.

 

My airbox is ontop of the engine not at the side. What does it look like and is there anything I should be aware when removing.

 

When a petrol engine idles the throttle is closed. That creates a vacuum (under pressure).
Whether 0,3 bar (4.5 psi) is exactly correct for your engine on idle I don't know. But it's at least close to what it should be. In general: the more you press the throttle pedal, the higher this reading will be.

Given the fact that your knowledge is limited, isn't it time to contact a professional?
Before you start replacing perfectly good parts that cost quite a bit of money.
Let's face it, for instance when I ask you to measure the fuel pressure you don't have the equipment to do that.

 

Hi

I agree with you on this but i dont have much funds at the min so if i can find out as much as i can myself before hand i can take this with me when the car gets booked in.

What tests should i ask my local garrage to do on the car?

The car juddered real bad this morning and nearly stalled and i got a DTC code from the reader which is below. Also done some tests see below.

With Key In and Engine Off




Engine On at Idel




DTC Code which was reported after the car nearly lost power this morning. I think the code was oly reported due to me nearly stalling the car due to the judder before.

 

Still trying to locate the TMAP sensor???

Chris

 

Evening all,

Would like to say thank you to the people who have given advise to me on my car issued on here.

Tonight i changed the fuel filter for a new one and still got the issue. Been quoted Ł44.00 for 1 Hour Diagnostics and a check of the car.

What if they tell me its a sensor issue which we have tested above

Chris

 

Update on the issue

Car has been in for a Diagnostics today. Compression check and other checks done and nothing wrong was found. They could replicate the issue so they fitted an OEM Coil Pack and it fixed the problem even that i have tried two new coil packs. He said the ones i tried are a cheap china brand and wont last 5 min. Has anyone ever known the cheap china brands to fail so quick even that i have tried two.

Pick the car up later

Chris

 

So with a compression check done and fuel preasure check done i cant beleave its the coil pack again.

 

If you have had a reported p0302 it could well be the coil pack, I have never used cheap coil packs on Fords as work in Ford repairer and only use genuine coils on them.

Have heard of cheap coil packs failing in the past though. Coils fails on most cars so not uncommon.

 

What makes are good as the garage took my cheap one off and the fitted a Bremi one.