81 240 "CIS" problems
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jmanguitar
81 240 "CIS" problems
i have purchased a 81 240 for 400 dollars and it will start up and than die a few seconds later. The "in tank" fuel pump was bad so i replaced it and that didnt help. So i took a look at the air meter/fuel distributor. When i move it manually with the throttle i can make the car run fine but otherwise it wont run very well. It is like there is something holding it back like a vaccum leak at the throttle body to air fuel distributor but it is ok. i dunno but i need help.
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Damion
Hi,
If by pushing up on the plate (called the "sensor plate") the car runs, it means the mixture is too lean.
A couple of possibilities (after basics like fuel filters/etc):
-Check for vacuum leaks, also around the injectors.
-The warm-up regulator could be defective...it should enrichen the mixture when the engine is cold, if it's not working, no cold enrichment which means it'll do exactly what you're describing. (Basically, it's only running for brief period on the "squirt" of fuel from the cold start injector.)
You can turn IN on the 3mm allen in between the air boot and the fuel distributor to richen the mixture, try about an 1/8 turn...(the adjustment is very sensitive so be careful). BUT...I would only do that if you have access to an exhaust analyzer (measure ahead of the cat) or a working O2 sensor to measure, because if the warm-up regulator is defective, and you richen the mixture so it runs cold, it will be far too rich when the engine has warmed up (high emissions and fuel consumption)...but at least this way you will be able to get it started so you can better check for vacuum leaks and whatnot.
The allen adjustment is kind of a PITA, it's often easier to remove the air boot (which is a good time to thoroughly clean the sensor plate, very important!).
Let me know if you have access to a gas analyzer and I can give you better tips to get it setup decently with an old warm-up regulator...
Hope that made sense:-)
cheers
If by pushing up on the plate (called the "sensor plate") the car runs, it means the mixture is too lean.
A couple of possibilities (after basics like fuel filters/etc):
-Check for vacuum leaks, also around the injectors.
-The warm-up regulator could be defective...it should enrichen the mixture when the engine is cold, if it's not working, no cold enrichment which means it'll do exactly what you're describing. (Basically, it's only running for brief period on the "squirt" of fuel from the cold start injector.)
You can turn IN on the 3mm allen in between the air boot and the fuel distributor to richen the mixture, try about an 1/8 turn...(the adjustment is very sensitive so be careful). BUT...I would only do that if you have access to an exhaust analyzer (measure ahead of the cat) or a working O2 sensor to measure, because if the warm-up regulator is defective, and you richen the mixture so it runs cold, it will be far too rich when the engine has warmed up (high emissions and fuel consumption)...but at least this way you will be able to get it started so you can better check for vacuum leaks and whatnot.
The allen adjustment is kind of a PITA, it's often easier to remove the air boot (which is a good time to thoroughly clean the sensor plate, very important!).
Let me know if you have access to a gas analyzer and I can give you better tips to get it setup decently with an old warm-up regulator...
Hope that made sense:-)
cheers
-
Damion
Also I should add to make sure you have fuel up to the distributer, a plugged fuel filter could do it but it would have to be almost totally blocked...
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