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Discussion Starter · #1 ·
My 94 Cobra has a rough idle. I've recent pulled the manifold off and found a mixture of oil/fuel on the manifold gasket towards the back two ports.:confused:

Recently I've have done an overhaul on my 94 Cobra, I've installed a Powerdyne Supercharger and 36lb FR injectors (Planning on installing the Walbro 255 pump this weekend).

I've checked the spark plugs and the wires, all are working. I'm planning on cleaning the mass air sensor later today and hoping for the best.

Any advice on what can cause oil/fuel to leak up to the manifold? What other signs should I look for or what other things do I need to clean/check.

Thanks,

Sean.:crying:
 

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I noticed u installed a supercharger so I have a couple questions and maybe help you out.
1. What the boost pressure?
2. Tuned?
3. I noticed u installed larger injectors. Is the maf matched to the injectors, or is the computer tuned for the injectors?
 

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What kind of crank case ventilation do you have?
 

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Check the o rings on the injectors too. Did you lubricate them properly before installing them? They can roll up sometimes and you get no seal...
 

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Discussion Starter · #5 ·
I'm a novice when it comes to working on cars, but I know how to read and be resourceful. So everything is trial and error for me right now.

I haven't had it tuned yet but its going to the shop this Monday. I actually ordered a new mass air to match the injectors only to have the tuner from the shop tell me to ditch it and it was old technology, is this true? I don't have a boost gauge but the pulley is good for 5-6 lbs.

I've change the plugs, check the wires and cleaned the mass air sensor, but no luck.
I'll have to check the injectors this afternoon. Makes sense now that I think about it.

Either way I need a tune. Just wasn't aware how crucial it was to get one ASAP. Just want to save some time and money by getting the Cobra in better shape before Monday rolls around.
 

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Your tuner is correct, all a "calibrated MAF" is is a MAF that is hacked to work with the stock tune and different than stock injectors. A tuner can just adjust the fuel tables on whatever MAF you already have to match your injectors.
 

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A bad fuel pressure regulator will suck fuel into the intake, check the vaccuum hose going from the regulator to the intake and make sure there's no fuel in it. As far as the oil, any engine with a PCV system on it is going to suck oil in, bottom line. You can install a separator in between the PCV and intake to try and minimize the amount of oil sucked in. I ditched my PCV altogether.
 

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Agreed, I tried the separator thing when I had my 95, ditching the PCV is the best bet, its a stupid design IMO. I also went with a Kirban AFPR which everyone said would not leak and it did not. I mean even if you have a stocker it could be going out...
 
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