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Discussion Starter #1
I haven't driven the car much lately but I had it out recently and it ran fine. I filled up with premium and parked in the garage. Today it started and idled just fine but seemed to stumble as I gave more than half throttle. I figured an Italian tune up was in order. It revved OK up to 3000 rpm then no power or revs. Last time driven (2 weeks ago), revved to 5000 easily.
 

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check for loose air fitting between the air filter box and the throttle body just don't look shake the motor pull on the hoses. if not that how old is the cat?
 

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Discussion Starter #5
Thanks for the suggestions. I checked the hose(s), seemed tight. The car has 54,XXX miles, I am 2nd owner, I believe the complete exhaust system is original. Plugs were replaced less than 2000 miles ago, will pull them tomorrow.
 

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If it feels like the brakes come on at 3000 rpm then I agree that it is most likely a fuel pressure problem that could be caused by a dirty fuel filter or a failing fuel pump. the best way to verify this is to Tee a fuel pressure gauge into the hose that goes to the cold start valve. The pressure should be about 38 psi. Rev the engine hard and watch the gauge. The pressure should not fall.

A failing ignition coil or distributor cap or bad spark plug wires could also produce these symptoms.
 

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I haven't driven the car much lately but I had it out recently and it ran fine. I filled up with premium and parked in the garage. Today it started and idled just fine but seemed to stumble as I gave more than half throttle. I figured an Italian tune up was in order. It revved OK up to 3000 rpm then no power or revs. Last time driven (2 weeks ago), revved to 5000 easily.

it strikes me that this is example number 36,987 of the thread " everything was fine , then i did something and now the car is bad " ... followed by answers and advice that often sound like " well... the polarity of the earth changed over night so now your battery is hooked up backwards "

all the advice offered may very well be valid and all that stuff may have gone bad in the last 48 hours but does it make sense ? car runs fine, put gas in it and now its doesn't .

ocam's razor ... " most of the time, the most obvuious answer is the correct one " and isn't that the most obvious place to start here ?

if what you say is precisely accurate and you aren't leaving anything out, then wouldn't you drain that gas out and see if its full of water or something ?

take the fuel filters off and cut them up and see whats inside ?

car ran fine... put gas in... car craps out

seems pretty obvious to me that something to do with that fill up either the fuel itself or something dislodged inside the tank either mechanically or simply rust and sludge is going to be the answer...

of course i understand the aliens from zoltron are at it again with their anti alfa death rays again...so it might be them as well.

i think bianci might have one of those aluminum foil pyramids you can put over it that solves this...
 

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[snip…] if what you say is precisely accurate and you aren't leaving anything out, then wouldn't you drain that gas out and see if its full of water or something ?

take the fuel filters off and cut them up and see whats inside ?

car ran fine... put gas in... car craps out

seems pretty obvious to me that something to do with that fill up either the fuel itself or something dislodged inside the tank either mechanically or simply rust and sludge is going to be the answer...
Hence mine and alfaparticle's fuel delivery-related suspicions… The car sat for 2 weeks after running fine. Nothing would have changed in terms of adjustment or component wear while parked… But if some crap made it's way into the fuel pump or clogged anything else during his last drive it could well-manifest itself through these symptoms. I've been through this scenario twice with my race car. Killed 3 (yes, 3) fuel pumps in two seasons. Certainly atypical fuel pump life on any car. Finally got serious about tracking down the issue and discovered there were trace amounts of rust floating around in the fuel tank that slowly over time clogged the fuel pump and significantly reduced fuel flow. (Once affected couldn't get over 5000 rpm on track…) The cure was to remove the tank, acid wash it and then reseal the inside to make it like new again. That was 4 years ago and haven't had any fuel pump failures since. It may not be the issue but it may be worth checking into. FWIW.
 

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I've been through this scenario twice with my race car. Killed 3 (yes, 3) fuel pumps in two season
s.

I went through the same ordeal with my GTV6. It had sat for years before I bought it. I killed Bosch fuel pumps which are very susceptible to debris in the fuel. Funny thing is, the cheap aftermarket pump that was in the car tolerated the crap in the fuel but it would not generate sufficient flow/pressure. I installed an industrial strainer in the fuel line upstream of the pump until I found a good, clean gas tank. I filtered out large amounts of scale.
 

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s.

I went through the same ordeal with my GTV6. It had sat for years before I bought it. I killed Bosch fuel pumps which are very susceptible to debris in the fuel. Funny thing is, the cheap aftermarket pump that was in the car tolerated the crap in the fuel but it would not generate sufficient flow/pressure. I installed an industrial strainer in the fuel line upstream of the pump until I found a good, clean gas tank. I filtered out large amounts of scale.
you need better fuel pumps. i raced for 25 + years and maintained a hundred different cars and you could count the fuel pump failures on one hand. i ran the bosch pump as the primary delivery pump out of the accumulator on what must ave been 50 different fuel injected race cars and never lost any. i can't remotely imagine why you had these issues. the vane type pumps don't like to sit around dry and they like to be gravity fed and as you note , if you get trash in them they can just jam but if you keep them wet or run a oil/fuel mix trhu them if they are going to sit for a long time they last just fine.
 

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i can't remotely imagine why you had these issues.
My theory is that the super-accelerated failure was compounded by occasional fuel starvation in the higher-G load right-handers and consequently the pump would momentarily run dry. Couple this with the rusty sediment I hadn't discovered yet inhibiting flow at the pump intake and this is why I think the situation was made worse. My race car is a 318is which has the smaller 14.5 gallon fuel tank with only the single in-tank fuel pump/pickup/sending unit. There is no secondary pickup pump, etc. Baffling in there is not at all adequate to deal with fuel starvation when fuel level is low. The 325 tanks do much better. Again, restoring the tank and ultimately keeping the pump clean ended up eliminating these problems for me. All pumps have been the stock Bosch units so far.
 

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Mine locked up within a couple of miles. They were genuine Bosch pumps of the type specified for Bosch L-Jetronic fuel injected cars. They have close tolerances and it does not take much to jam them.
 

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Mine locked up within a couple of miles. They were genuine Bosch pumps of the type specified for Bosch L-Jetronic fuel injected cars. They have close tolerances and it does not take much to jam them.
sure. but that doesn't kill them. aside from the fact that a good screen stops this, you just take the pump out and reverse the polarity and it runs backwards and pushes the junk out. then you run some oil rich cleaner thru it and its like new ( clean the internal screen first ) it takes 30 minutes but a sub micron pre filter keeps it from happening at all.
 

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sure. but that doesn't kill them. aside from the fact that a good screen stops this, you just take the pump out and reverse the polarity and it runs backwards and pushes the junk out.
I tried that. I also tried soaking the internals in solvent. The only way to free them was to disassemble them.
 

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Discussion Starter #15
The fuel pump was replaced when I bought the car ~2 years ago, along with tune up (and refurbish radiator). I hadn't planned on letting it sit for so long or I would have stored properly or at least add Stabil. When I drove it a couple of weeks ago I was surprised that it didn't even cough or sputter. It had ~1/4 tank of old fuel so I bought $20.00 worth of 93 octane and drove home (still ran fine on the way home). My first thought was fuel filter, maybe the fresh fuel dislodged some crud or something. Now that I see examples of relatively new fuel pumps failing, I will have to consider that as well.
 

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You can buy a fuel pressure test gauge from harbor freight for about $20. That will tell you for sure if it is a fuel issue and it will show you when you are making progress. I have one permanently plumbed in to my GTV6.
 

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Discussion Starter #17
I figured I'd limp the Spider to the storage garage and swap for the Targa until I got time to deal with the running issue. On a hunch I added some Lucas Fuel Injector Cleaner, fired it up and the car ran beautifully. Pulled up to the garage and decided to leave the P-car there and keep driving the Alfa! I still want to drive it a few more times before I pronounce the problem solved, but for now I'm happy.
 

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I figured I'd limp the Spider to the storage garage and swap for the Targa until I got time to deal with the running issue. On a hunch I added some Lucas Fuel Injector Cleaner, fired it up and the car ran beautifully. Pulled up to the garage and decided to leave the P-car there and keep driving the Alfa! I still want to drive it a few more times before I pronounce the problem solved, but for now I'm happy.
lets assume, for the sake of discussion, that the " cleaner" dissolved some obstruction and allowed fuel to pass sufficiently to get the car to run... well done for that but don't kid yourself that that is fixing anything. that obstruction or clog or whatever it is or was is a direct function of contamination from some much larger issue that is waiting to ambush you. if you are smart you will cut the filter open and see whats in there. what can often happen in instances like this is that when you now ( or soon ) park the car for an extended period, the fuel sytem dries out and the crud thats in there hardens up and will sieze the pump or harden inside the injectors and become a real problem when you go to restart it in the spring or something.

if you cut the filter open and its nice and clean then fair enough ... problem solved and you are on your way. but if you open it and its full of rust or black slime from a rubber hose or something, then thats something you are going to want to address sooner rather than later...
 
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