Need Some Chevy Advice, Please!
03-17-2003, 12:40 PM
#1
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i bought a 1990 beretta for a hundred bucks, it no longer has the 2.0 engine in it, it now has the 2.8 engine, theres no exhaust whatsoever except for the manifolds and there is no air filter assembly,just a throttlebody. are there sensors on the airfilter assembly, theres are a couple wires that plug into something but nowhere to plug them in, the car idles rough and i dont think it knows how to compensate for all the additional air, if i plug and unplug some of the vacuum lines on the throttlebody the car runs better and almost idles perfectly, would anyone here know more about these engines than i do? id really appreciate the help 
03-19-2003, 04:13 PM
#7
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the manuals for the car dont really explain anything about the vacuum lines and where some of them go, i know there is a sensor on the intake pipe but there isnt any big *** air flow sensor like all the new 3.1, 3.4, 3.8's. it idles and runs great, i just have to feather the gas pedal when im at a standstill for a second, it needs new spark plugs, its getting a new exaust system this week. i gotta find the intake assembly somewhere, prob a junkyard, it leaks tranny fluid, i put 2 and 1/2 quarts in it today, it sat for 3 years, i think its just the trany pan gasket. shifts kinda rough though. its kinda weird, none of the manuals really tell where or what all the sensors are and since its not a 2.0 four banger and now a v-6 2.8 the vacuum line diagram on the hood isnt worth a ****,lol. if anyon has anymore ideas keep em coming, the engine runs great the way it is now, wonder how its gonna run with an exhaust sytem instead of just the headers and the intake sensors hooked back up? it only has to last me a month. after that i can sell it for a grand, hehe i only paid 100 bucks for the damn thing.
03-19-2003, 04:28 PM
#8
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Location: NJ
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ok a few things.....
1. how many sensors are on the throttle body itself. 2 or 3? it there are only 2 then you are missing the airflow meter that goes downstream in the intake system. GM changed the design so many times I can't remember what goes to what. does the throttlebody have like a screen blocking the opening? if it does then the airflow meter is part of the throttle body, if there is no screen and you can look inside and see the "butterfly" when you move the throttle then the airflow meter is seperate from the throttle.
2. without an exhaust system the O2 sensor cannot get an accurate reading of exhaust gas due to fresh air getting sucked into the exhaust manifold like a vaccum when you let off the gas. this will cause the sensor to tell the computer the car is running lean, and richen up the mix!!!
let me know whatelse you need to know, I work on theese junks all day long!
Jay
1. how many sensors are on the throttle body itself. 2 or 3? it there are only 2 then you are missing the airflow meter that goes downstream in the intake system. GM changed the design so many times I can't remember what goes to what. does the throttlebody have like a screen blocking the opening? if it does then the airflow meter is part of the throttle body, if there is no screen and you can look inside and see the "butterfly" when you move the throttle then the airflow meter is seperate from the throttle.
2. without an exhaust system the O2 sensor cannot get an accurate reading of exhaust gas due to fresh air getting sucked into the exhaust manifold like a vaccum when you let off the gas. this will cause the sensor to tell the computer the car is running lean, and richen up the mix!!!
let me know whatelse you need to know, I work on theese junks all day long!
Jay
03-21-2003, 10:33 AM
#9
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theres no sensor on the throttle body, so i guess i need that, i have the muffler shop putting on the exhaust right now. fixed the gas leak. its weird how good the car runs without any intake system at all and no exhaust,lol. one other thing, the car has a digital dashboard,all the gauges work except the oil pressure guage,it constantly blinks and it says the oil pressure is at it maximum level,lol. i think the sensor is either unplugged somewhere or broke cause the motor is fine. thanks for all the good help.
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