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Discussion Starter #1
My 86 alfa romeo has been acting up. Occasionally it will misfire (it could do it more often than i realize). I will be having a new clutch put in as it does occasionally slip. However twice it has hesitated like a carbd car when the carb is not properly tuned. it was fine when I shifted into N out of any gear. I revd it and she was fine. It was like she couldnt put the power down and she didnt like having the pedal floored (wasn't driving like a maniac, just running tests on it). It would go then no power (not slipping at that time or reving any higher) then go with power again. I recently awoke the car from a long slumber and I drained all but 2-3 gallons of the old gas as that is all I could get out. Mixed in new gas with some additives. New cap, rotor and plugs very recently. However i did not do new wires as I was sent the wrong wires. she was running just shy of the 175 mark on my temp gauge which is right in the middle. It had no signs of overheating. Oil pressure is fine, right at 57, though sometimes when idling the gauge will drop. The coolant does need a flush however no overheating signs present. I let it sit for about 10-20 minutes (luckily it happened in front of a friends house) and was fine and continued down my merry way. It did not cool down much in that time as it was sitting in the very hot Hawaiian sun. If my memory serves me right it was around 130-140.
 

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L-jet is very intolerant of intake air or vacuum leaks. All air entering the engine must pass through the Air Flow Meter (AFM). Intake air or vacuum leaks are called 'false air' which messes the computer's fuel calculations.

From your description of symptoms, I'd suggest checking the large air duct across the top of the engine very closely for splits or tears - especially in the accordian shaped folds. As the engine moves on its rubber mounts it can open up a split allowing false air in and the AFM will send erroneous info to the computer. Then, as the engine settles back the split can close up and it'll run right (for a while).

See the link in my signature for a page of info about the L-jet system in our cars.
 

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Discussion Starter #6
L-jet is very intolerant of intake air or vacuum leaks. All air entering the engine must pass through the Air Flow Meter (AFM). Intake air or vacuum leaks are called 'false air' which messes the computer's fuel calculations.

From your description of symptoms, I'd suggest checking the large air duct across the top of the engine very closely for splits or tears - especially in the accordian shaped folds. As the engine moves on its rubber mounts it can open up a split allowing false air in and the AFM will send erroneous info to the computer. Then, as the engine settles back the split can close up and it'll run right (for a while).

See the link in my signature for a page of info about the L-jet system in our cars.

Thank you for the info, I actually have replaced that hose, as the original was ripped a good 2 inches.
 

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Another possibility

While I agree with the others, here are a couple of other possibilities. It may just be the bad gas that you left in the tank. The bad stuff will almost always go to the bottom where the fuel pump picks it up. If you pull the fuel sending unit and find the strainer dirty, you should probably siphon out all of the gas from the tank.

Also, I found that the vacuum hoses, both under the hood and in the trunk get rock hard over time and need replacing. You may need to replace the ones in the trunk. They are fairly inexpensive at about $45-$50 for the set. (This also helps get rid of fuel orders that may migrate to the cabin.)
 

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Discussion Starter #8
Thanks for all of the replies!! From my fuel line attached to the tank, it goes the the main pump, then to the filter and then to the line.

To go from the tank to the pump, it is straight, it does a 180, straight, another 180 and then to the pump. To the filter it goes a little to the right, then a 90. From the filter to the fuel line running to the engine, it's straight and then a 90 to the right. My fuel hoses are kinked, from research no pre-bent fuel line. Suggestions?





Sorry for the rude and crude drawing but I am far from an artist.

T --- Tank , P --- Pump, F --- Filter.
 

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L-Jet

In the past I had problems with the vacuum advance sensor. It was causing an air leak. I would not mess around with the AFM. You can adjust the idle by the 19 and 17mm nut on the intake plenum. Also check each fuel injector, a clogged or non functioning injector can wreak havoc.
 

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Those gradual curves in the fuel line are not the problem. What could be is the fuel pump in the tank. I had similar symptoms to yours when my pump failed. There are videos on YouTube on how to replace it, and you can get one cheap. I found one for less than $20 at a local auto parts store and it was identical to those sold for over $100 at IAP or Centerline. Alfa uses the same pump used by General Motors during the '80s.
 

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Discussion Starter #11
Those gradual curves in the fuel line are not the problem. What could be is the fuel pump in the tank. I had similar symptoms to yours when my pump failed. There are videos on YouTube on how to replace it, and you can get one cheap. I found one for less than $20 at a local auto parts store and it was identical to those sold for over $100 at IAP or Centerline. Alfa uses the same pump used by General Motors during the '80s.

The drawing does not due it justice unfortunately, it is not gradual. It is kinked. The in tank fuel pump is new. I actually did order my first new one from centerline and it failed. So I replaced it and so far it's doing pretty well.
 

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It may be that your fuel line from the tank to the pump is too long, or too short, causing the kinks. According to the Workshop Manual and the photos I just took under my car, the curves should be gradual.
 

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Could it have been changed? Everything looks stock.
It certainly could have been changed. If you have access to the Workshop Manual, page 04-11, you will see what I mean by the line being too long in your drawing and how it could cause a kink.

You may be able to find the drawing through a Google search, but I would recommend that you buy the manual from IAP, if you don't have one.
 
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