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Hello all. I have posted once about my issues, thrown some shop time and parts at the car, and no resolution yet.
Earlier this summer I replaced my distributor, plugs and wires because the car was running rough. That did not resolve the issue. At this time I started seeing the passenger side CAT glowing on the header side.
I replace the coil, O2 sensors, and fuel pump (this was done without testing fuel pressure, only done because of mileage being 140,000).
No dice. Cat still glowing red on passenger side.
Took it to a shop to have CAT checked and they replaced plugs again and said I needed new injectors.
Put the new injectors (bosch III from FIC) in the other day and now the car runs better, CAT doesn't glow, but it is not accelerating well at all. It feels like there is something plugging the exhaust or at least creating a lot of resonance inside the car.
I still think it's the CAT, but before I pay any more shop labor, any other ideas?
Since it's glowing only on one side, after a plug change, you should check the plug wires to make sure they're on the right terminals on the opti-spark.
The passenger side of the engine, from front to rear, is 2-4-6-8. The order on the opti should be, top to bottom, 4-6-8-2.
With car idling, go to the back and put your hand first over the drivers side exhaust outlet. Feel for how much pressure it puts out. Then do the same for the passenger side. If the pressure is lower on the passenger side, you may have a plugged passenger cat. Overheating it may have caused damage.
With car idling, go to the back and put your hand first over the drivers side exhaust outlet. Feel for how much pressure it puts out. Then do the same for the passenger side. If the pressure is lower on the passenger side, you may have a plugged passenger cat. Overheating it may have caused damage.
This guy is right about one thing and that's the fact that an overheated cat could easily be damaged. This would cause low power for certain. Yiu need and exhaust back pressure tester that you thread into the o2 sensor hole. Basically any back pressure means you need a new converter.
With a cold engine, start it and let it run for about 30 seconds. After turning it off, check the exhaust manifolds at the heads for heat. If you have a bad cylinder then one or more pipes will be cold.
You might have the famous crossed plug wire problem. "I checked them and they're OK", followed a day or two later by "I found two wires crossed after I checked them again".
Since it's glowing only on one side, after a plug change, you should check the plug wires to make sure they're on the right terminals on the opti-spark.
The passenger side of the engine, from front to rear, is 2-4-6-8. The order on the opti should be, top to bottom, 4-6-8-2.
I've checked and double checked. It idles fine and revs smoothly. Thanks
With a cold engine, start it and let it run for about 30 seconds. After turning it off, check the exhaust manifolds at the heads for heat. If you have a bad cylinder then one or more pipes will be cold.
You might have the famous crossed plug wire problem. "I checked them and they're OK", followed a day or two later by "I found two wires crossed after I checked them again".
I haven't checked after the shop replaced the plugs again. Maybe they didn't get them back on right.
This guy is right about one thing and that's the fact that an overheated cat could easily be damaged. This would cause low power for certain. Yiu need and exhaust back pressure tester that you thread into the o2 sensor hole. Basically any back pressure means you need a new converter.
Thank you both. I'll try the hand check - it was fine before but making a puffing sound probably because of the bad injector.
I'm hoping I didn't foul it up too much, but the O2 from the passenger side was pretty black
This guy is right about one thing and that's the fact that an overheated cat could easily be damaged. This would cause low power for certain. Yiu need and exhaust back pressure tester that you thread into the o2 sensor hole. Basically any back pressure means you need a new converter.
With this. Another easier way to check for a clogged cat is to hook up a vacuum gauge to manifold vacuum. Run the car in neutral, and bring RPM up and hold. If vacuum falls off, as you hold RPM, that is indicative of a clogged exhaust -cat in your case. Easy, fast test.
I would also check the fuel pressure regulator as it may be letting fuel into the manifold. Pull the vacuum line and check for fuel. On my 1992 this caused the cat to glow red.
With this. Another easier way to check for a clogged cat is to hook up a vacuum gauge to manifold vacuum. Run the car in neutral, and bring RPM up and hold. If vacuum falls off, as you hold RPM, that is indicative of a clogged exhaust -cat in your case. Easy, fast test.
Getting back to this, car starts rough but idles fine. Exhaust pressure is great on both sides, but both used to have some white smoke at start up, now only the driver side does. My coolant slowly goes away from my overflow tank in the bumper, but I'm now wondering if I have a gasket leak, or if it's just me worrying. I checked the oil, but I'm no expert on how it should smell or look. I don't see any separation of fluids on the dipstick or in the top tank.
Getting back to this, car starts rough but idles fine. Exhaust pressure is great on both sides, but both used to have some white smoke at start up, now only the driver side does. My coolant slowly goes away from my overflow tank in the bumper, but I'm now wondering if I have a gasket leak, or if it's just me worrying. I checked the oil, but I'm no expert on how it should smell or look. I don't see any separation of fluids on the dipstick or in the top tank.
Thanks all for the suggestions.
Sounds like coolant in the cylinder at startup. If this were my problem, then I would drive it around and get it hot then put a cooling system pressure tester on it and pump it up to 15psi. I would let it sit there for many hours and possibly overnight. Then I would pull the plugs on both sides and crank over the engine. I betting that one or more will belch out coolant. I would do it this way because this is a very conclusive test, and considering the amount of work to correct it; you need to know for sure without guessing.
10-19-2015, 08:08 PM
Need some help a 92 LT1 issue.
With this. Another easier way to check for a clogged cat is to hook up a vacuum gauge to manifold vacuum. Run the car in neutral, and bring RPM up and hold. If vacuum falls off, as you hold RPM, that is indicative of a clogged exhaust -cat in your case. Easy, fast test.
