REZN8R

All of a sudden my otherwise perfectly running car lost power on the highway and won't respond to throttle inputs. If I shut it down for awhile then start it up, it runs fine for about 10-20 seconds then does the same thing. It will always start right up, but will only drive about 15 mph and sounds like a detuned lawn mower! Any suggestions? It's a 3.1L with an auto and 99K on the odo.

WaynesRS

Have you checked your plugwires , plugs , cap and rotor ?

ZZ28ZZ

Fuel filter??

Hulk0202

Check for codes, then post the results and we will have a better idea of whats going on.

REZN8R

I was able to drive it home without a problem last night. I'm thinking it might have something to do with engine temperature. I'll check for codes later tonight.

REZN8R

I checked the codes last night. I got a code 13-oxygen sensor. I guess that solves the problem huh?

REZN8R

I replaced the O2 sensor and thought everything was fine. Nope. It did the same thing again. Any ideas? I'm guessing something that controls the whole motor. Not just an injector or a spark plug, but more like the ignition coil or the fuel pressure regulator.

rezinn

I think I remember that 13 is o2 sensor rich. Does the car burn oil? You're right, it could be too much fuel delivery or not enough spark. If you've got an extra coil I'd change that out and see what happens. Check the plugs and see if they're a bit black.

REZN8R

Thanks, I'll do that.

FJK

Rezn8r:
Have you fixed your problem? I've got an identical problem with my 92 V6. Let me know if you can.
Thanks, FJK

REZN8R

I finally got it to a dealership and they said 3 of the 6 injectors were totally shot. 2 more were on their way out. The scenario they told me was when one injector went out it took out the fuel supply for the whole fuel rail (which explains the running at 15 mph). Then when an injector went out from the other fuel rail the car would die. If I changed the injectors myself it would cost around $600 (the dealer wanted $1200), so I'm using it as an excuse to do a V-8 swap.

FJK

Thanks for the quick reply REZN8R, but I don't know if I buy into the dealerships explaination. You are running fine, & then 3 injectors die. With my car, I am still maintaining the same fuel pressure when engine starts to run out of power. I'll keep you posted on what I find.
Thanks again, FJK

REZN8R

I found the same thing with my car. The fuel pressure remains constant. I noticed the voltage gauge reading ominously low though. I tried replacing the alternator, but it didn't work. I also replaced the ignition coil and cap & rotor to no avail

ZZ28ZZ

I'd be digging into that low voltage issue. Check the battery voltage with an accurate voltmeter. If the system voltage is low with a new alternator and eng running, look for bad connections at the alt and battery. Also check ground connections from the eng to body.
That might be the cause of your fuel delivery problem. Computers don't like low voltage. On the TPI eng I'm building, 4 of the injectors fire at the same time (batch fire). Wouldn't be suprised if the V6 didn't fire 3 at a time.
Are the 3 bad injectors on the same side of the eng?
Injectors are pretty reliable. 3 failing at the same time seems just abt impossible.

As far as buying injectors, check EBAY. I recently bought eight lightly used 24 lb injs for $125..

FJK

REZN8R:
As I said, I would reply back when I finally found & corrected the problem. Well, it's fixed. The problem was 2 bad injectors with shorted coils. Should have listened to you sooner. Found a couple of ex-GM techs where I work & they descibed the scenario. If you have a shorted injector coil (resistance will measure low), the injector will draw more current from the ECM. This limits the current to the properly functioning injectors & they begin to deliver less fuel. Supposidly, the ECM detects excessive current draw to the injectors, & to protect itself, shuts down current supply to all injectors, thereby stalling the engine, or in my case allowing it to idle only. No trouble codes will be set. I knew the sympton felt like the car was running out of fuel. Later, the problem would occurr so quickly, like a switch was thrown, the problem also seemed electrical. Well, what I described fit the bill on both counts. I replaced my 2 injectors with new AC units, which are about $90 each. I've noticed Summit offers Acell injectors for less than $200 for 6. If you want to fix your car yourself, it's really not hard at all. Remove the upper plenum, which is just nut & bolt work. You can even get by with reusing the gaskets. Electrically disconnect the injectors & ohm them out. Each injector should be 11.8 -12.6 ohms. Replace the ones not in spec, which will probably be low. Mine were 9.8 & 3.4. You could even go to the junk yard & pull injectors after checking their resistance. To remove injectors, un bolt the fuel rail & gently pry up on the rail, front & rear until all the injectors break free & pop up. If anyone needs more details, I will be happy to assist. According to the GM techs that helped me, 95% of these types of problems are fuel related.... injectors & fuel pumps, especially on V6 engines.
Regards, FJK