Maf For A Y2k 2.3...

[MikeyGman]

Hi folks, have been reading the site for ages.

 

My missus has a Y2k 2.3 with just over 60k on the clock, we've had it since 29k and full fraud history. But over the last year or so, performance has just dropped off to the point where the car will do 0-60 faster if you gradually increase the accelorator compared to just flooring it.

 

After getting overtaken by a 1.2 corsa last weekend, I thought enough's enough.

 

So I disconnected the MAF and found that there was absolutely no difference. After a few trials of "connected" and "not connected", there is definately no difference - other than the engine management light coming on/going off...

 

There seems to be different opinions as to whether "no difference" means it's a good or bad MAF...

 

What do you think?

 

Thanks,

[mumof4]

no diff=maf knackered.

 

 

age and milaege is about right aswell

[MikeyGman]

Thanks for your quick response.

 

But it's a big "ouch", as they're

[sepulchrave]

Errr, this car is a PETROL Gal, MAF's really don't make that kind of difference! Look elsewhere for the likely fault. ;)

[Guest HairyPlateEater]

IIRC they are an exchange part and can be exchenged at either Fraud dealers or approved Bosch retailers for around

[MikeyGman]

"sepulchrave" that's an interesting statement about the MAF's & petrol engines, it would explain why there's no difference whether it's connected or not. Sortta makes you wonder why they bothered!

 

So what do you think my next option is - O2 sensor & cat replacement? It's just had a service which made no difference.

 

I was going to do a compression test but I 'hear' that you need a special tool to get the plugs out of the 2.3engine, anyone know it that's true or another 'mechnically engineered' story to stop us from making improvements and saving big wads of cash?

 

?

[sepulchrave]

They bothered for emissions and fuel economy, on the TDi engine the MAF makes a huge difference 'cos it's turbocharged. You get about 100K out of non-turbo MAF's before they die, and about 50K as mo4 stated on TDi's.

 

Lamda probe probably not and Cat makes no difference to performance either. My guess would be HT, coilpack maybe?

 

If the dealer ran a diagnostic as part of the service and everything was peachy then it's HT for sure since that will not usually show up, I think the spark may be breaking down under lean conditions. Modern lean burn engines require really fat sparks to fire properly.

 

Compression will be fine unless you've done the Weston beach race with no air filter! ;)

[MikeyGman]

Hey, thanks for the advice - it's likely to save me a fortune.

 

The car's always had a slightly bouncy rev counter when idling but it's been getting worse lately too. Nothing that's really noticeable - but you notice it if you look carefully at the rev needle and listen to the engine tone. The dealers say they can't see anything wrong so they changed the sparkies, then the exhaust and now they're talking about taking the head off which starts ringing pound signs in my ears! ;)

 

I'll get a quote for the coil pack and leads.

 

Cheers bud. ;)

[Guest emjay]

I am trying to find the cause for poor performance on my V6, the HT pack is new, I suspect MAF but don't wanna buy one just to prove it!. Can MAFS go gradually and cause lumpy acceleration and poor performance?

[sepulchrave]

emjay, you should really have started a new thread for your problem since your vehicle is totally different.

 

I'm guessing that since you mention a new coil pack (singular) then your car is a 12v VR6 (it would help to say so!) in which case HT leads are the most likely culprit. I changed my MAF (mine was totally U/S) and the only difference it made was to improve fuel consumption slightly, however if you're in any doubt then just unplug it, drive it and report back.

[Guest emjay]

Thanx for helping, I don't know if it's 12V?, but it only has one coil unit (right hand side fixed on the head) with all six leads coming out of it - I didn't know there were other types. I changed the coil pack cause of misfires, I tried running with the MAF unplugged and it was noticeably worse, wouldn't rev well and lumpy on acceleration, so thats why I thought mine was just deteriorating rather than completly U/S, The leads could be the cause but again they are expenive and I don't want to waste money. The leads fitted are about 3 years old.

[MikeyGman]

Hi folks, I've still a problem with the Gal - any further thoughts?

 

The symptoms are:

 

* When warm and ticking over, the rev counter bounces around the 800rpm mark - sometimes dropping to about 650 and sometimes going as high as 950

 

* When warm, there's "minimum" power in the low rev range (1000-3500rpm) meaning you have to keep changing up/down gears when trying to get up even the slightest incline or when overtaking on motorways/dual carriageways etc

 

*Putting your foot down full seems to make the car accelerate slower than applying increased pressure to the accelerator (almost as though you're waiting for the engine to catch-up with the throttle)

 

Since I last posted on this topic, we've changed the coil / leads / plugs and had it serviced. Changing the leads and coil fixed a slight misfire we had when the engine was cold - but the above problems still remain. It's also had an MOT and passed on emissions...

 

So anyone got any ideas on what can be causing these problems? It gets kind of embarrassing when you're being overtaken up a hill by a fiat 126! :lol: (Although I get my own back on the way down hill!!!)

 

Thanks,

Mike.

[El Dingo]

Hi MikeyGman,

If you take out the spark plugs, what colour are the tips?

Have you had a good look around the engine bay, especially the inlet ducts for breaks/splits?

Idle stabilisation is a problem... so the I(dle) S(tabilisation) V(alve) might be faulty/gummed up?

[MikeyGman]

Strange enough, I'd got the plugs out this morning just to check them over.

 

They are motocraft platinum and the tips were a dark grey - not quite black. I checked the gaps whilst they were out and noticed they were all over the place (0.5mm on one and over 2mm on another) so I've set them all to 1mm, but it's not made that much of a difference yet.

 

I did a quick checkover of the rubber hoses at the back of the engine bay and they 'look' ok, but I'll do a better check one afternoon this coming week.

 

I've seen mention of the ISV, but I need to find it. Any clue of where it's located on the Y2K+ 2.3 engine?

 

Thanks.

[MikeyGman]

Hi folks, it's been some time but I've now got the opportunity to try and fix this problem.

 

I've replaced the plugs, leads and coil which has settled down some of the idling problems and given me a huge increase on MPG - I was getting around 28mpg but now I'm getting around 34mpg on my daily 20mile commute. I've taken the ISV off and cleaned it out with carb cleaner (it wasn't that dirty anyway) and checked all the vacuum pipes etc for leaks. I've found the EGR and when I pull the pipe off, it turns right ruff - almost cutting out until I put it back on. :D

 

Just to recap, the problems I have are:

 

* When the engine is cold, the car stutters around the 2500rpm when accelerating through the rev range for the first minute or two.

* When the engine has warmed up, the Gal runs sluggish upto about 3000rpm and then she really picks up upto about 5,500rpm in each gear - but she's not misfiring or stuttering

* When the engine has warmed up, there is a slight bounce in the idle - perhaps within 100rpm that you can just see through the rev counter needle bouncing and the engine tone changing

 

I've just bought a obd2 connector just to make sure I'm not going mad, and can definately see the bounce in rpm when the car is idling. But the bouncing seems to be in line with the timing advance as I notice that this is constantly changing whilst the engine is idling. Is this constant change of timing normal when idling, because when I touch the accelorator and hold it at about 2000rpm - I notice that the timing advance remains constant....?

 

I'm now thinking about buying 2 new o2 sensors and a new MAF which will eliminate all the "usual" suspects for these kinds of faults - but if this doesn't fix it, what do you folks believe to be the next action? I'm running out of idea's now! :D

 

Thanks in advance,

Mike.

[Andrew T]

It seems like you've covered things pretty thoroughly but a couple of thoughts........

 

People who've had problems with the 02 sensor have generally been victims of an MOT failure on emissions levels rather than noticing any drop off in performance. You should have been given a print out as part of the MOT paperwork showing exactly what levels were recorded - were they near the limit? I recall that buying a none Ford sensor sometimes failed to cure the problem, so genuine part is the best way to go.

 

As far is the MAF is concerned you really shouldn't be having problems with a petrol one at this mileage. They're a pretty long life item (mine is original at 150K) and I've rarely known them to be replaced. Because they are very different from the Diesel one in construction they apparently are cleanable! The instructions were posted a long time ago by Scorpiorefugee in one of his early topics.

 

Finally an obscure thought, although it's unlikely given the age and mileage of your car, but I once traced a similar problem to a perished brake servo pipe which was allowing extra air into to be drawn into the cylinders diluting the Fuel/Air mixture, but still operated the servo.