Originally Posted by Josecuervo

I purchased this car with 48,000 miles in August and while in basically new condition it has some issues to work through. I'm pretty sure it was left standing for long time without running since the tires have a manufacture date of December 2000. The car originally was from Quebec.

Symptom: fuel smell at airflow meter flapper, 7.5 - 9V duty cycle (rich), intake misfire and stuttering acceleration below 2500 RPM.

- So far the tune up basics have been done: plugs, cap and rotor, fuel filter.
- All of the rubber Vac lines look remarkably in like new condition for the age.
- OVP is OK.
- Replaced Fuel Pressure Reg due to 6 . 6.5 bar reading. Now it's at 5 / 5.5 bar reading. CIS-E nominal system pressure is 6.3 bar!
- Replaced Throttle Body Gasket due to leak.

I'm leaning toward a problem in the throttle position sensor, but I'm not sure if I'm diagnosing this correctly. Write ups are kinda all over the place on the TPS. Here's what I'm seeing.

- Deflecting the air flow sensor plate results in a standard 10% change, which rules out the Airflow Poteniameter.

- Measuring voltage at the x11 port at roughly 7.5 - 8.5V. When the throttle is engaged, it runs all the way up to 11.4v regardless of throttle position; no sequential voltage increase.

- Running the engine and measuring the duty cycle in volts, I'm seeing 7.5 - 8.5V at idle, 4.5 - 5.5 V at 2500 rpm. That's off I think.

Duty cycle measurements are to be made in %s, or in degrees. 100% = 90 degrees. A dwell meter is convenient.

- The curious measurement from the X11 is at a steady 1500 RPM which is where I'm getting a hesitation and popping in the exhaust. I'm getting a reading in the 6 - 7 v range, HOWEVER as the cycle progresses it drops out to 0v and then picks up at 6.5V. I don't see this at the 2500 RPM or any other range.

The TPS is a switch, not a continuous sensor. Closed throttle sends one signal to the ECU, WOT sends the other, nothing in between.


So how should I interpret this? I don't want to rip the fuel distributor off again without diagnosing this correctly.

Thanks - appreciate any help you can offer.