Brought my '90 V6 cross country. Went to get a CA smog, it failed on 2500 rpm CO. Immediately went to DMV to get a temp tag, and it barely made it back.
Now when the engine hits 160* or 180*, it immediately loses all power and begins missing. Like throwing a light switch. One second it's fine, the next it's running extremely poorly. If you depress the accelerator more than a hair, it stumbles and will backfire if you press hard enough. It has just enough power to hit 20 mph on perfectly flat ground after 30 seconds of acceleration.
I work on a military base, and it's at the shop there. It runs great cold, but there's no way it would make it the 15-20 miles into town.
I started with a set of plugs. New wires. New cap and rotor. Other than a slight oil leak on one valve cover, all looked great. Injector cleaner in tank. Fuel treatment. Tank is full. New oil, new air filter, new fuel filter.
Mechanic found a hole in the radiator, thought that air cavity was causing temp misreading and ECM was dumping fuel to warn engine. Replaced, pressure tested all hoses good. Mechanic tossed on new EGR (I think?), But says it had no effect so took it back off. Replaced factory O2 sensor (oops!). Said IAC looked brand new and clean.
He's out of ideas. I'm almost positive it's not fuel flow. Fuel pump less than 1 year old / 5k mi. Have not had time to check pressure at rail, but the backfiring makes me doubt it.
Only out $290 for radiator and O2, including labor. Plus cost of tuneup parts.
Need ideas for things to troubleshoot. Have full access to bays, lifts, most of the shops tools. Can get free mechanic assistance. Or hire mechanics at reduced hourly rate. But not idea where to go now.
have the same problem?
Thursday, May 26th, 2011 AT 10:55 PM