1997 geo metro 4Cly Auto Terrible Acceleration... Please Help me solve this!

[Zechariah]

Okay so it a 1997 Geo Metro LSI 4Cly Auto and the acceleration is terrible!

I could start out faster on a bicycle, floor the gas and it lags for 1-2 seconds before it slowly accelerates. If I stomp on the gas really fast it almost kills the engine, I have set the timing to 5 degrees btdc, the spark plugs are one month old with proper gap, the fuel pressure is right, I don't know about the fuel injector I haven't checked it.

Could anyone give me a suggestion of what to check? (fuel injector? should I just replace it or should I try to check the spray pattern?)

Thanks,
~Zechariah

[Johnny Mullet]

Since you checked spark and fuel, the next step is a compression test. Readings should be no less than 156 PSI per cylinder.

[Johnny Mullet]

Sorry for the double post, but the "Edit" button is borked on Firefox along with the Fast Reply for some reason.

After the compression test, try removing the cat and see if it comes back to life. The cat may be plugged. Mine become plugged after having burnt valves. I rebuilt the top end and had no power. All the raw gas going into the cat melted it down.

[Zechariah]

My compression is 150-150-150-150 this is fine right? I just replaced the head gasket a month ago. I haven't checked the fuel injector yet so I think I'll do that and then maybe take the cat off, I'll let you know what happens.

Thanks,
~Zechariah

[Woodie83]

No, that's worn out, it should be around 200. Was that done with the engine warm, all plugs out, throttle wide open?

Try the disconnected exhaust test that Johnny recommended and you should also check your cam timing, could be one tooth off. If you've got the ignition timing set to 5 before, the distributor should be near the center of it's adjustment slot. If it is then the cam timing is probably good. Moving the timing to 10 before should help you out a little until you figure out the real problem.

[DOCTORBILL]

Does your oil turn black after maybe 1,000 miles? How many miles on the engine?

If you are going to replace/rebuild the Head, maybe you should do the Rings at
the same time.

I did mine w/o removing the Engine from the Metro.

If interested - we can give you links from this Forum showing how to do it.

DoctorBill

[brivers]

My guess is you either have a vacuum line off or stuck egr valve. Also check your MAP sensor.

[doug2060]

The minimum compression is 156 psi.

[DOCTORBILL]

Are you sure that your Compression Gauge is working properly?

I find it quite odd that all four cylinders measured exactly 150 PSI.

That is statistically very strange....

Maybe 145, 153, 160, 175 - but not 150, 150, 150, 150 !!!!!

DoctorBill

[doug2060]

I though he was just rounding it off...

[fubard]

I'd double check the cam timing before starting to rip it apart. I assume you didn't check the compression before the head gasket job.

Originally Posted by Zechariah

My compression is 150-150-150-150 this is fine right? I just replaced the head gasket a month ago. I haven't checked the fuel injector yet so I think I'll do that and then maybe take the cat off, I'll let you know what happens.

Thanks,
~Zechariah

[Zechariah]

Well I fixed it, turns out the timing belt was off a few teeth.

Thought I'd post this in case anyone else has a similar problem.

~Z

[gandl2123]

Hmmmmm, the nasty "Cam Timing" issue. Yep, if the cam is not in time with the pistons this can lead to poor performance. I had another problem that might have been the cause and is a problem with some of the Geo metros befor 1996 and automatic.

There is a box under the steering column that controls the transmission and shifting. I had to change this as mine would be in 2nd or 3rd gear just sitting at the stop light. Tromp the gas and "blaaaaah" and barely moving. Pull the gear shifter down to 1st gear and she zoomed away.

The transmission was not automatically shifting down to 2nd and then 1st as you slowed to a stop. Make sure you are in 1st gear when you come to a stop...

Tks

[1gasenvy1]

Hi, I never heard about this box under the steering column what does it look like and what does it doo again. I'm have the code PO420 come up and maybe this is the problem. It's a 1996 4 cylinder auto.

[Woodie83]

0420 is the rear O2 sensor, which is only there to monitor the catalytic converter. You have a bad sensor, bad connection to the sensor, or bad cat.