Thenewt078

Hey all, I've been on the site (not a member) for some time, and just recently joined. I have some minor inconveniences with my Firebird. It's a 1992 3.1 Base model Auto, completely stock (as far as I know). Now, when driving the car it has a slight bog/stutter a hair past idle when accelerating lightly (doesn't do it if you mash it) and it only does it sometimes, I have not put a pressure gauge on it (I work at an atv dealership and they're not the same fitting lol) and all the ignition system has been replaced and on time. Is it possible for the outside ring of the balancer to shift and cause an incorrect reading on the timing plate? I've heard 2nd hand from a few old techs that it's a possibility. Another slight inconvenience is fuel economy, it suffers from horrid fuel consumption (about 12-13 city, and 19-20 hwy). If anyone can point me in the right direction on where to go with this it would be much appreciated. Thanks All

maroe624

injectors

Thenewt078

Dirty or bad? Is there any way to test them before buying some?

LiveIt!

Unclip the wiring harnesses from them and probe the connectors with a multimeter, you want to see them test at around 15 OHMS. I have 3.1 injectors in my car and they tested at 12 Ohms I think but still run fine

Thenewt078

Sweet. I'll hook an ohm meter up to it and see how much resistance they have then. Has anyone else heard of the outer ring on a balancer shifting positions and throwing the timing marks off?

maroe624

Just swap em out . Their gonna cause you problems down the road. Pick up some ford injectors f1ze. I got mine off a 3.8 mustang. Better response and acceleration.

drdave88

iTrader: (3)

Yes your balancer can shift if the rubber is old, you'll be able to see if it's all dry rotted and cracked.

Before throwing parts at it, get a fuel pressure gauge and see what's going on with your fuel system. Does it hold pressure after key off, for how long and how much does it drop? Have you put on a new fuel filter? How long ago (mileage) did you do the plugs/wires? Were they gapped properly and are they the correct plug for your engine? Check engine light on? etc etc etc.
I'm not saying the injectors are good or bad, but don't just throw parts at it because "their gonna cause you problems down the road". Might as well just lease new cars to keep a warranty all the time with that mindset. Be a good tech, do some diagnosis and you'll figure it out.

Thenewt078

I did a tune up a couple thousand miles ago (plugs, wires, cap and rotor, fuel filter, and oil change.) I'm not sure how much pressure the pump is holding I'll have to check, and there is no check engine light. I've put a timing light on it and the mark is almost 45 degrees retarded but that can't be right because it wouldn't run with that much timing pulled out of it. I have a chilton manual and followed the instructions as stated for adjusting timing but I didn't touch anything because I knew something was up for the timing to be that far off.

HitchDav

45 degrees retarded, that sounds like you were checking the timing without disconnecting the EST jumper. In the Chilton it will mention a single wire (tan IIRC) that needs to be disconnected when checking or setting the timing. If you already did that, and your fuel pressure & injectors check out, you might want to take a look at setting your timing in the 10-14 degrees BTDC range.

drdave88

iTrader: (3)

The EST connector is a single wire (tan with a black stripe) connector sticking out of the wire harness running above the heater box on the passenger firewall. Unplug it, then start the car and check timing once the engine is warmed up. Stock timing is 10 degrees.