- Dec 4, 2013
- 4
- 0
- 2
1991 LX 5.0 automatic convertible. 100% stock top to bottom end to end. 50k miles on the engine, 250k on the transmission and body.
No EEC codes.
Runs well at idle, at cruise, at normal throttle opening (normal driving around town and on the highway). They only time I have a problem is at quick throttle opening and at WOT.
Symptoms:
1. If I got to WOT quickly from a stop (or if I "blip" the throttle in park) it will backfire through the intake one or two times. It is more pronounced when the engine is cold.
2. If I go to WOT from any speed and hold it at WOT (floored) the engine struggles to increase the RPM's past 3,000. It feels like it simply has no power - it falls flat at 3,000 RPM. It will get to 4,300 and the transmission shifts, The RPM's drop because of the next gear, start to climb, then it falls flat at 3,000 RPM again.
I has a recent tune up. Fuel pressure is good. It does not run like it has a vacuum leak.
Do I have two problems or is it the same problem causing both issues?
I am starting to wonder if the catalytic converters are clogged. As far as I know they are they original converters (30 years and 250k miles).
No EEC codes.
Runs well at idle, at cruise, at normal throttle opening (normal driving around town and on the highway). They only time I have a problem is at quick throttle opening and at WOT.
Symptoms:
1. If I got to WOT quickly from a stop (or if I "blip" the throttle in park) it will backfire through the intake one or two times. It is more pronounced when the engine is cold.
2. If I go to WOT from any speed and hold it at WOT (floored) the engine struggles to increase the RPM's past 3,000. It feels like it simply has no power - it falls flat at 3,000 RPM. It will get to 4,300 and the transmission shifts, The RPM's drop because of the next gear, start to climb, then it falls flat at 3,000 RPM again.
I has a recent tune up. Fuel pressure is good. It does not run like it has a vacuum leak.
Do I have two problems or is it the same problem causing both issues?
I am starting to wonder if the catalytic converters are clogged. As far as I know they are they original converters (30 years and 250k miles).