Rebuilding a Mass Air Flow Sensor

On 2/10/2012 9:50 AM, Guv Bob wrote:


an old Eclipse or shell out $400+ for a rebuilt one or donate it for next to nothing off my taxes.

I got no responses from the car groups, and thought maybe one of the electronics RCM gurus here might point me in the right direction with this.

and is idling rich. First thought was to manually adjust the idle mixture. Wrong. Can't do it on this car -- everything comes from the computer.

does it have an iac valve? i had one go out on my vette that caused the same symptoms.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Some (but not all) of that older stuff could display 'codes' in a fashion. First you need your factory shop manual, then either by shorting connector cavities, or possibly a switch on the computer, you'd count blinks of either the 'check engine light', or an LED on the computer proper. You'd then look up your blink code number/s in the manual.
I still have a hunch that you may have a bad coolant temp sensor. Usually when they go bad, they tell the computer that the engine is really cold. The computer, dumb and dutiful as it is, believes this, and based on the sensor data runs the engine very rich mimicking some or all of the duties of the choke on older cars. The sensor check procedure is quick, simple, and detailed in your factory shop manual.
Other trees to bark up are a possibly stuck on or leaking cold start valve, and/or it's timer/control circuit. If so equipped, these were just an injector spraying into the intake manifold (another choke like enrichment device from days past). Some had various timer circuits/devices to turn the cold start valve on when/if necessary, and off again soon as it was not... but if they failed could leave the valve on. These cold start valves systems were problematic with some models. Complete info is, you guessed it, right there in your factory shop manual.
Your manual should also have extensive troubleshooting charts and related info.
Let us know how it comes out!
Erik
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

More... got me thinking, and on a whim looked up this:
<http://en.wikipedia.org/wiki/Thermotime_switch
Erik
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.