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Alfa V6 running like a dog


Ned

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Hey guys. Got 2.5L Alfa V6 motor thats running like a dog. Previous owner told me it used to run on 4 cylinders but he got it to go on 6 again.

Problem i'm having is that it looks like it's back on 4 again now. Its epicly down on power and sounds like a subaru.

Have checked all the leads go to the right place (Alfa marks the leads, the rocker cover and the dizzy so just followed the numbers! isnt that handy?) also pulled all the plugs out to check if they sparked. There is a mix of plugs in there which bothers me but they all spark so thats ok(ish) but stil runs like a dog.

Havent tested compression or fuel because injectors scare me and dont have a compression tester.

Anyone wanna lend me one or something? Also, whats the deal with injectors? how do i see if they work? with carbs it was simple.. just have a look down its throat and done.

Was also gonna ask the dude i got the car off how he got it going but wanted to test basics before bothering him.

Any ideas?

Ned

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That'll teach you for getting an Alfa! First I would replace the spark plugs so they are all the same, unless the rear bank has platinums or something.

Injectors need high pressure fuel and power to produce a good spray pattern. You could pull the injectors out and get them flow tested, they'll be able to tell you if they are working correctly.

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i know man. The more i think about it, the more it just seems like the timing is out... givin that all plugs spark and i get epic unburned fuel smell and some backfires tells me i'm getting fuel too so could only be compression or timing right? the car runs but just like a dog and is way down in power.. fuck i hate cars... also glad that now i'm forced to get my hands dirty again though :D

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Its a 155. I know it wasnt the sensible thing to do, but it was the fun thing to do. I havent bought any fun cars for ages so thought it was about time :) and everyone should have owned an alfa once in their life right? might just fix it, sell it and buy a toyota haha

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Kind of ironic, the local MITSUBISHI nut warning people off buying specific makes :P

I'd find a decent Alfa forum and just search there for similar problems. Like you say, it does sound pretty simple but there can sometimes be problems that relate specifically to individual cars, coils, ignitors, plugs, that kind of shit. With all my Opel problems I have I've found people off shore have run into all of them before and have easy fixes for most (replace engine/car etc).

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Gheck for air leaks between manifold and AFM, can make 155's run like shit and feel like there missing

You sholud get it on the scan tool, sure someone on here has one you can use to get codes.

O2 sensors fail too

failing that check and scrape clean dist cap, bet its furry as fuck..

Mean car btw

Did my apprenticeship on those tugs, not as bad as people would have you believe..

Remember every fault mechanically or electrically gets blown out of proportion on Alfa's as people love the storys

even the customers used to boast about how many warranty claims they had made.

In reality they were a lot better than most euro products and other high end jap stuff of the era

and now have one of the highest customer satisfaction ratings, and still using the V6..

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Two good Alfa forums:

http://forum.alfa156.net/forum

http://www.alfaowner.com/Forum/

I'm suffering a couple issues with myne too.

1) When cold, the car pops, and farts and doesn't rev above 3k etc for the first couple hundred metres.

2) Engine hesistates when hitting 5400rpm. Shame really cos the v6 screams beautifully between 6 and 7k.

But it's a very sweet car otherwise!

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Had a couple days off so been playing around with it.

Found out that it's number 2 and 5 not going. It's got spark on those cylinders and numer 5 has fuel (number 2 is a bitch to check so assuming its the same problem as 5 as they are oppposites in the V shape)

So i got fuel and spark so must be missing air/compression yes? andy DIY way to check for this at all?

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Heres some more. Middle ones are 2 and 5

24062009018.th.jpg

24062009017.th.jpg

looking at the bottom i'm guessing they are grouped in 2's so good chance that could be it? wonder what they cost to replace :(

Any way to test them?

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Well when you said 2 & 5, yeah. That was my guess right off the bat. The use of a wasted spark shared coil system that 2 & 5 use would seemingly verify that guess. Still, it might not be. Sweet car though man, love those Alfa's.

If there's another car you can grab a coil-pack from, that you know runs sweet, then by all means do that first.

Just make sure it runs sweet first and also pull the plugs from 2 & 5 and give them a clean, because if they're fouled and you put a working pack in, it'll still run slightly hamburgers until they've cleared up on a nice hot run.

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