I have a 99 Grand Am with the 2.4. It recently started having issues with excessive fuel consumption and lack of power. It is now at the point where it will drive well in town up to 60 kmph, but after that it has a shifting hesitation and strugles to get to 90 kmph. It may maintain speed for a short time at 90 to 95 then dies off as if a governor kicks in. Various codes have come up and I have repaired those issues without solving the problem. So far I have replaced the EGR, O2 sensor, air intake temp sensor, plugs, fuel filter, injector seals, and repaired a vacuum leak. There is no fuel in the regulator vacuum line, and currently there are no codes coming up. I have cleaned the air intake components and changed the air filter, and used a can of sea foam treatment in the tank. No sucking in of air when I remove the fuel cap. I have been unable to find an adaptor to hook up a fuel pressure tester. What about buying a new filter, drilling a small hole in it, and welding a test fitting from a junker into it? Would be pretty hard to monitor from that location while driving though. I would have to rig up some kind of extention for the pressure tester. What do you think- fuel pump, pcm, or something else?
Can't get the car to full speed
- Thread starter pigger
- Start date
I find myself without a compression tester. In this small town I don't have access to tool rental either. Was not suspecting ignition issues as none of the previous codes indicated them. When I removed the plugs they looked in perfect condition. I found a parts car to rob stuff from so I'm going to replace the ignition components. Would expect with these symptoms to get a p0300 at least. Did have that once before replacing the plugs. Have heard a battery can cause the PCM to flip out, even if it is strong enough to start the car with no issues. All I have access to here is a load tester, not an electronic diagnostic tester so I hate buy a non-returnable battery if that isn't the problem. Can't even drive the car to the city to get it checked.
Already had to cut the fuel filter off because the release tabs were gone, so not looking forward to dropping the tank either. Don't suppose this model allowed access to the pump thru the trunk floor?
Had one car like that, was pretty sweet.
Timing issues should throw a code as well. Just did the water pump in the fall and everything looked good behind the cover. Ran perfect after that.
Already had to cut the fuel filter off because the release tabs were gone, so not looking forward to dropping the tank either. Don't suppose this model allowed access to the pump thru the trunk floor?
Had one car like that, was pretty sweet.Timing issues should throw a code as well. Just did the water pump in the fall and everything looked good behind the cover. Ran perfect after that.
Hamilton North
New member
Sure it's not a timing issue? No pinging (lean or advanced timing) or backfiring (rich or retarded timing)? Is the cat abnormally hot (rich)? Plugged cat?
Could you have an emissions test done on it?
Could you have an emissions test done on it?
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Really not showing any signs of timing. No ping, no backfire. Runs smooth thru a full range of RPM until a load is applied. If it starts to struggle at higher speeds and downshifts to compensate, you can watch the speed drop like a rock until you let off and the rpm-to-speed ratio comes into ballance.
Could try an exhaust gas test but pretty sure it will confirm high levels of unburnt gasoline based on fuel consumption, but the symptoms came on way too sudden to make me think cat. Be a few days before I can look into it again.
I appreciate any and all input though.
Could try an exhaust gas test but pretty sure it will confirm high levels of unburnt gasoline based on fuel consumption, but the symptoms came on way too sudden to make me think cat. Be a few days before I can look into it again.
I appreciate any and all input though.
