My friend has a 2001 Blazer Extreme. In July it started to have rough starts and run a little rough. He took it to the dealer this month and they diagnosed it as an intake gasket leak and repalced that. It still started rough. Now it doesn't start at all. I have been able to get it to start after it has been hooked to a charger for a few hours, but it still doesn't run well. When it does start, if you try to floor it, it will go up to about 3k rpm and then stay there, but from 1k to 3k you don't really gain any speed and it takes forever to downshift. When it gets stuck at 3k it sounds like a rev limiter. Does anyone know what this issue could be?

The check engine light is not on.

 

i had similar problems with a grand prix I had and it was either the maf sensor or cam sensor (both replaced at the same time so not sure which one it was) but i suspect it was the maf sensor. My car didn't throw any engine codes so i just had to start replacing things. If I were you, i would check the fuel filter to make sure it wasnt clogged and check the fuel pressure at the fuel rail too. It will be kinda hard to diaganose without it throwing any codes but the 3 things your car needs to run are fuel, air and spark so i would start chenking the major components involved in those. Although, since the dealer thought it was a leak in the intake gasket, I would take some starter fluid, spray around the engine and see if you can find a leak somewhere else. Hope that helps a little, should at least give you an idea of where to start.

 

does it smell like rotten eggs (sulfer) when driving it? If it does, check the cataillac converter.

 

It probably isnt the MAS..... I have a 2001 blazer and My MAS went bad. It definitely sets off the check engine light.

 

Does your friend have a K&N style oiled/foam filter??? If so then you can try to clean the MAF sensor with CRC MAF Cleaner. It will have to be removed and taken apart. The part to be cleaned is the "plastic" part between the two aluminum adapter ends. It is mounted on the air cleaner box. Most of the time depending the amount of oil/dirt that has collected on the fine wires you can just spray the wires clean. Only on certain instances will you need to use a "Q-tip" swab to carefully wipe the wires (these are extremely fine wires and will break easily if care is not taken).

Some times this helps. If this does not then there may be a problem inside the plastic upper intake plenum. Here are some possible problems:

1. Leaking fuel pressure regulator.
2. Leaking fuel meter body.
3. Stuck (open/close) poppet valve.
4. Vacuum Leak
5. Torque converter

Hope this helps get you going in a positive direction.