QuestionQUESTION: Hey, I just rebuilt the carburetor (Rochester dualtjet) on my 1985 Cutlass Supreme Brougham and have finally assembled everything but noticed before I put it back on the manifold that the seat gasket in my rebuild kit was different from the original one on the car. The original one was a little thicker and had a plug that connected to two heater grids under where the barrels would empty into the manifold. I found one that AC Delco makes that would cost over $200 to get including the shipping from a local parts shop, but I'm not sure I can shell out the money just for that gasket. My question is what would be the benefit for having that gasket, and should I just go ahead and use the plain gasket from the kit?
ANSWER: Hi Adam,
That's not a gasket, it's a Mass Airflow Sensor. The engine will not operate correctly without this part. Typically, rebuild kits do not include the MAF sensors which is why yours did not. It is not intended to be replaced unless it is faulty. The gasket included with the kit is probably to mount the carburetor to the sensor which in-turn gets mounted to the intake.
Thanks for the question, I hope this information is helpful to you.
Kb
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QUESTION: I may be wrong about this, but I'm almost 99% certain that mass air flow sensors are only on fuel injected engines. The carburetor does all the air/fuel mixing depending on the pressure within the carb. Also I did some digging and found out that it is an Electronic Fuel Evaporator that aids with startups in cold weather so the choke doesn't have to be overused, as well as aiding with cleaner exhaust.
AnswerHi Adam,
I'm not going to argue with you, it's 'obvious' you know more than me and I should be asking YOU questions.
That said, You are most certainly wrong about MAF sensors only equipped on EFI engines. ANY vehicle that includes an engine management computer (yours does) is equipped with four basic sensors: TPS, O2, MAP and MAF. The fuel delivery system does not matter as most later-model produced carburetors (like yours), and nearly ALL foreign-built carburetion was aided by EMJ (Electronic Metering Jet) injectors. The MHW-AFM (Modulator Hot Wire-Air Flow Meter) mounted under your carburetor was not designed to do EFE and has nothing to do with warming the engine up so the choke works less. If you think warming the fuel mixture up a half-of-a-degree is going to assist in allowing the choke to work less or the engine to reach NOT (Normal Operating Temperature) quicker is just wrong. Let me explain: As the air-fuel mixture flows through that heated plate, it cools the grid-plates producing a voltage drop that the computer 'reads' as a resistance value along with the O2 sensor to determine proper mixture control via the EMJ(s) mounted inside the carburetor. The EFE system is an emissions control device and has nothing to do with fuel management. The EFE works in conjunction with the EGR and Vapor-recovery to reduce NoX emissions from carbureted engines. Oh yeah, you don't have to trust my word, if that device ONLY aids in cold-engine operation, warm the engine up to NOT and disconnect it and observe how well the engine operates WARM, without that MAF sensor attached.
Please don't reply back with argumentative statements, the answers received here are based on ACTUAL EXPERIENCES and not text-book answers that do not help anyone. I don't care what the next guy said or what the last guy said.
Thanks for the question, I hope this information was helpful to you.
Kb
