Stumbling When Floored

[The Dude Abides]

Fired up the old soob (ea82) the other day and let it idle for a bit. Thought id give the peddle a few kicks before turnin it off and it stumbled for a couple seconds when floored. I tried this over and over again and it did it every time. I floor it, it boggs down for 2 or 3 seconds then takes off. What could be the cause of this. Most tuneup stuff has been done.

[thomasakehoe]

First off I'm new to the older Subies, but have been wrenching on everything I own for a long time. Is it carbed, SPFI or MPFI? either way sounds like the air fuel mixture isn't being able to correct it self when you're blipping the throttle, if its FI could be an O2 sensor getting worn not being able to signal the ECM to the rapid load changes or a fuel metering problem. If it was ignition related you could check by taking it for a ride and go up a steep grade a weak spark will make it self well known when you try and push the pedal hard (putting a load on the engine) going up hill it will ping and buck. Hope this gets you started.

[The Dude Abides]

Thanks and sorry for not being more clear. Though lots of people on here know me its always good to post your cars info. Its a 1988 Subaru DL Fuel Injected.

 

When i do drive it it doesnt present itself that problem when going up hill. Only when starting off in 1st and 2nd gear reallly. I havent been able to check codes because one of the Previous owners disconnected the check engine light. But to be honest with 210000 on the clock i wouldnt doubt the o2 sensor is due.

[thomasakehoe]

Might want to just do a quick timing check too.

[The Dude Abides]

I dont knwo how to do that.

[xbeerd]

I dont knwo how to do that.

 

do you have a timing gun?

 

if so, pop the square rubber plug on the rear of the engine above the flywheel, clip the timing gun lead to the #1 plug wire and star the car, shoot the timing gun into the whole it'll tell you where your at, it should be set at 20 degrees, if not, stop the car, loosen and rotate the distributer a little bit to adjust it. then fire it up and recheck.

 

you could probably get one on loan from advanced auto or autozone for free (deposit refunded when item returned)

 

also, pull the belt covers off and check tension on the timing belt?

[thomasakehoe]

I believe you need to connect the test connectors to lock out the computer from adjusting the timing and then connect the pickup of the timing light the flat clamp to the number one spark plug wire and warm up the engine so the idle is steady it's suppose to be around 700 RPM and then flash the timing light on the timing marks on the crank pulley by pulling the trigger and see where the timing is set at it should be 20 degrees BTDC I believe if anyone else knows more details please chime in. Oops someone beat me to it. didn't know the timing marks were on the back of the engine. Great site for help.

[xbeerd]

I believe you need to connect the test connectors to lock out the computer from adjusting the timing and then connect the pickup of the timing light the flat clamp to the number one spark plug wire and warm up the engine so the idle is steady it's suppose to be around 700 RPM and then flash the timing light on the timing marks on the crank pulley by pulling the trigger and see where the timing is set at it should be 20 degrees BTDC I believe if anyone else knows more details please chime in. Oops someone beat me to it. didn't know the timing marks were on the back of the engine. Great site for help.

 

yeah, the green plugs too doh!

 

IIRC, there is a mark/arrow udner that plug, and then the degrees are shown on the flywheel.

 

havent done it in a few months

[eulogious]

+1 on the timing... Seems like that's all I have said in the last few days, kinda wierd...

 

When my t-belt was going on my MR2, it did the same thing, because the belt had jumped a couple teeth and need to be replaced. Seemed to idle and drive fine, just a little stumble. Hell I drove it for pizza delivery for 6 months before finally taking it in, so it was very subtle.

 

Good luck dude!