Not Sure if this Belongs here, but It seems to Encompass more Than Just the Carb

Some of You may Have read My Fuel starvation Post, and i have further narrowed Down the Problem.

Unplugging the TCS Solved the stumbling problem, But the Carlost performance and Gas milage really went Bad.

I plugged the TSC back In, and Unplugged the Mixture Control Solenoid , The net Effect was Identical to removeing the TCS, except Now Im getting Check Engine Light, And the gas Milage seems to be Better.

Now, I dont know wtf to Do. This is my first experiance with Comp Controlled vehicles, and any and all help is appriciated.

as far as Code #, I dont know how to get them, like i said I know Jack **** about the specifics of Comp Control.

Here is what I assume, that the TCS is malfunctioning in some manner, causeing the ECU to read the throttle positin improperly, Wich then Causes the Mixture to be set Wrong, Leading to the motor Leaning Out under accerlation Making it lose massive power.

Unplugging the TCS will Keep the ECU from changein the mixture, but That is costing WOT performance and Milage ( the TCS is ther for a reason... )

Unpluggin the MC solenoid is just keeping the ECU from changing the mixture, and this is causeing an error code To be reported by the ECU as the MC solenoid isnt functioning properly. the Same performance and Milage Problems would still remain.


and I mean TPS, not TCS, damn brain Fart.

Any ideas? I really Need to Fix this Post-haste.


the fuel pressure is a constant 5-6 PSI at the carb throught the RPM range, so thats not a factor.

This carb has 149,000 Untouched miles on it, So Something breaking/wearing out is very likely.


Thank you

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85 Z28 - Daily Driver
60 Ranchero - Project ( Money Hole )

 

Bort,

It's unfortunate that your first experience with the ECM system has to be with an E4ME carburetor. The TBI and TPI systems are so much more straightforward and less complicated from a control perspective. The E4ME was a transition between carburetors and full digital fuel control, and it shows.

Your throttle position control (Idle Speed Control) operation is essentially a function of engine speed only. If the idle speed is not at the desired point for a given engine coolant temperature, the ECM will try to adjust accordingly.

The TPS sensor is used to determine what mode the enrichment solenoid should be operating in. High TPS voltages should produce a richer adjustment, lower TPS should cause a leaner idle or cruise mixture. All of this is checked against the oxygen sensor, and further adjustments are made to get things into control. The baro sensor is also used as a reference to check throttle angle and apparent engine load, altering the mixture even further. If one or more of the sensors are out of range, the system can be trying to enrich for one condition while trying to lean for another condition.

I would suspect that after 150,000 miles, the old Rochester needs some attention, just to get everything back into a "normal" condition so the ECM can do it's job. Here's an idea of what you're looking at:



The ECM expects to see an electrical load at the mixture control terminals, thus the code.

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Later,
Vader
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"Make Me Bad"
Adobe Acrobat Reader 4.0

[This message has been edited by Vader (edited November 19, 2000).]