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Discussion Starter #1
Hi all,

Time to revive an old thread as I need to go sort this out next week.

Problem: My GTV is very 'lumpy' at low rev range. Ok once revs pick up. e.g. around a car-park I have to keep dipping the clutch as at walking speed it 'kangaroos'. Or if you go to pull away quickly without a lot of Gas, it will do the same.

Due its 96k Service now ish (94.5k) which will include Plugs.

Suggested it could be Air-flow sensor?

Needs to go on a diagnostic computer.

Anyone know probable cause? Anyone know good place (Bristol/WSM) that has a computer/good for servicing/reasonable?

Thoughts anyone?
 

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When your driving the car do you get a delayed throttle response - if you do - check the connector in the passenger footwell (remove the screws holding the carpet in place (next to the key switch for disabling the passenger airbag) - unplug the connector (white if I remember correctly - you will get no response from the throttle if you have the correct one) use some contact cleaner if the contacts look corroded & reconnect. It transformed my car !! - Best of luck

I know of a decent indie in Plymouth if its any good

Regards

Jon
 

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Discussion Starter #3
No I don't get a delay as such.

Plymouth is a bit too far. Unless they can do all the work While U Wait..
 

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AFM probs are usually in the mid/high rev range.. ..I was under the impression that diagnostics can't pick up AFM probs

how's your battery? - when mine was dying I got some weird kangaroo stuff that went when I put in a new one.
 

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Discussion Starter #5
Well it seems ok, but did have it run flat months ago due to a faulty radiator thermostat. So it's not likely to be 'great'?
 

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I was under the impression that diagnostics can't pick up AFM probs
They can tell if it's running rich or lean which points to a dodgy MAF, something to do with knock sensors or something.

When I cleaned my MAF and had the error codes cleared there were a few codes that indirectly referred to the MAF.
 

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Discussion Starter #7
Two 'specialist' centres have said:

1. MAF or Lambda probably but needs to go on computer.
2. MAF probably but needs to go on computer.

I don't mind paying for a new MAF but I don't want to end up chasing the problem around the car.

Problem is, the place that is near to me with a computer wants min of ~£300 for the service. Which seems high for a load of checks, oil, and filters (turns out NO plugs needed at this service).

Where to go...???
 

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You might not need to buy a new MAF, it might just need a clean and that could save you about £100.
Here's a guide - Fun starts @ 3000!

To check yourself if it's the MAF, disconnect the cable that goes into the side then drive it about and check if it feels any different.

To be honest, Phil's right, normally MAF problems show themselves at about 4500 revs, so it could be the lambda.

£300 seems a lot for a standard service, I'd definitely try and find a decent indie that'll give you a better rate.

They might be a bit of a distance but AlfaWorkshop shows a 96k service as £127. Might be worth the drive.
 

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The advice I've heard given in the past for similar probs is that you should unplug the AFM (easy to do, electrical connector abouve the airbox I think) and then the car will go into a sort of "limp home " mode where it won't have the normal power but should drive ok - if you do this and the problem's still there then it's not the AFM
 

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it won't have the normal power
It should have the normal power. The MAF regulates the richness of the fuel mixture, with out it it will run incredibly rich, but will perform normally as the fuel's not being restricted.

With a dodgy MAF the fuel mixture will be lean and you'll lose up to 50bhp.
 

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Discussion Starter #11
You might not need to buy a new MAF, it might just need a clean and that could save you about £100.
Here's a guide - Fun starts @ 3000!

To check yourself if it's the MAF, disconnect the cable that goes into the side then drive it about and check if it feels any different.

To be honest, Phil's right, normally MAF problems show themselves at about 4500 revs, so it could be the lambda.

£300 seems a lot for a standard service, I'd definitely try and find a decent indie that'll give you a better rate.

They might be a bit of a distance but AlfaWorkshop shows a 96k service as £127. Might be worth the drive.
These were one of the 2x specialists, but they are MILES away... but may go there if no-one has any better suggestions?
 

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You might want to post in your regional forum to see if there's any recommendations closer to you.

If not, then a couple of hours on the road to save a couple of hundred quid seems worth it to me.
 

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Discussion Starter #13
I'm tempted to agree... Besides...I've never been to Royston... lol.
 

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MAF is usually the upper rev range - 4000 + so probably not this.
Maf output and lambda can be checked on AlfaDiag - £80 to buy so cheaper than hook up to dealer's machine.
My suggestions:
1. Rubber induction hose - the one with the bend that goes into the throttle body - this fails underneath the ribbed bit due to the oil crud that gets sucked in from cam cover. The only way to check properly is remove it and flex it. A quick temp fix (and check) is a good wrapping of duct tape. This is less noticable at higher revs as the air leakage is negligable compared to the lungs full of air the V6 is sucking in. At low revs you're running a very lean mixture.
2. Dirty throttle body - the stepper motor flap gets dirty with oil drawn in from cam cover and upsets the idle/low speed setting. This can be cleaned when the above inlet pipe is removed - carb cleaner toothbrush and a little care. Move the flap very slowly or you can damage the stepper motor. Then do an ecu/throttle reset.
3. Plug and or coil pack. 96 k is long time to go for coil packs. The way to test is take off and replace each fuel injector plug one by one, when you get no change in the engine sound you've found the duff plug/coil pack/cylinder. To check if its a coil pack, swap with one of the other cylinders and see if it "moves" to that cylinder. If it doesn't then its the plug not the coil pack.
The plugs should have been changed at 60k, so they could be getting a bit tired at 36k. It is not uncommon for the rear bank of plugs to NOT be changed ay 60k even by main dealers (from personal experience) as they are a complete pain to change - this applies to coil packs too!
5. V6 is very fussy about a good battery for best perfomance (so called relaible German Bosch electrics..... :) )
 
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