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ea81 surging problem. HELP!!


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Need help Here .Have an ea81 81 gl hatchback here and shes been having s bit of a problem. Awhileback, it started surging out of nowhere. It sounds like its missing alot. While Holding a constant throttle, once you get up to 2000-2500 rpm, the thing bogs down and drops to 1k, then itll go back up to 2500 again and then drop again. It acts like its not even firing at all, like the whole thing just shuts down but gets up again. This happens more severley around the 2k to 2.5k rpm but you can also slighlty feel it around 65mph. Lately its been getting worse and wont hold an idle very well in the mornings. Ive replace cap, rotor, wires, rebuilt the carb, rebuilt the distributor, replaced ignition coil. Ive checked for vaccuum leaks and havent found any. Carb fuel bowl looks fuel all the time but the fuel seems to just trickle into the rear filter. Never had a filter up front. CHecked all my grounds and fuses and they look good. Even thought it might be my cataytic converter so i removed it. Still does the same thing and havent been able to diagnose the problem. Anybody had this problem before? any help would be appreciated

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Need help Here .Have an ea81 81 gl hatchback here and shes been having s bit of a problem. Awhileback, it started surging out of nowhere. It sounds like its missing alot. While Holding a constant throttle, once you get up to 2000-2500 rpm, the thing bogs down and drops to 1k, then itll go back up to 2500 again and then drop again. It acts like its not even firing at all, like the whole thing just shuts down but gets up again. This happens more severley around the 2k to 2.5k rpm but you can also slighlty feel it around 65mph. Lately its been getting worse and wont hold an idle very well in the mornings. Ive replace cap, rotor, wires, rebuilt the carb, rebuilt the distributor, replaced ignition coil. Ive checked for vaccuum leaks and havent found any. Carb fuel bowl looks fuel all the time but the fuel seems to just trickle into the rear filter. Never had a filter up front. CHecked all my grounds and fuses and they look good. Even thought it might be my cataytic converter so i removed it. Still does the same thing and havent been able to diagnose the problem. Anybody had this problem before? any help would be appreciated

 

It could be a lot of things, but it sounds like it is most likely clogged fuel circuits in your carb. It sounds like you have a Hitachi since you are able to see the fuel level in the bowl. Does your car have all the original vacuum and emission stuff?

 

You can do a rudimentary cleaning of the carb, by removing the choke body and carefully removing and cleaning the small bits one at a time, but I strongly suggest getting a manual before you do that and familiarize yourself with the carb.

 

The best thing would be to rebuild your carb or get a Weber...if it is the carb that is your problem.

 

If you haven't changed your fuel filter, you should do so, even if it looks like it is still good. They're like $3 and can cause similar problems to the one you are experiencing.

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It is the hitachi and it does have all the original emissions stuff. Im sick of the hundred million vaccuum lines going to it and i dont have emission laws where i live so im thinking of just ditching the hitachi alltogether. U read my mind because ive been thinking about picking up a weber 32/36 from redline. Simplify it and toss the emissions crap. The only thing is, if a new carb wont solve the problem, what will?

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U read my mind because ive been thinking about picking up a weber 32/36 from redline. Simplify it and toss the emissions crap. The only thing is, if a new carb wont solve the problem, what will?

 

Yep go for the Weber. If you are at elevation I recommend the manual choke. Part of the problem with all the emissions stuff is that it can throw things off and be extremely difficult to diagnose.

 

You can't go wrong with the Weber, so I would suggest changing the fuel filter and grabbing the Weber asap. Once you have the engine cleaned up and simplified it will be much easier to move on from there.

 

You might check your distributor shaft for play, but your description so far sounds more like fuel to me.

 

By the way, do you have rust in your gas tank?

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Yeah about a year ago, it started shutting off and eating up caps and rotors like no other. Had lots of play in the shaft so i got one from the junkyard. Im pretty sure the tank does have rust in it. Fuel filtr turns brown after a while. Be a good idea to drop it and clean it it out?

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Be a good idea to drop it and clean it it out?

 

Cleaning it out would be good. You could also check and clean the fuel uptake tube. the best thing would be to replace the tank or coat the interior. I planned on treating one of my tanks at one point but never got around to it. There should be several threads on that procedure and others on the internet.

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  • 2 weeks later...

So i finally got my weber and put it on. Ditched emissions and plugged all unnecessary vacuum ports. Replace fuel filter and added another inline right before the carb. Set my timing at 10* and adjusted the carb. Runs ALOT better then before. Slight Surge is still there but not as bad. I dont feel like im going to be thrown from it anymore. Its not jumping at 2500rpm anymore but all through out the rpm range. Still has a slight miss but not as noticeable. Another issue thats happening now is its dieseling after i shut it off.

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Set my timing at 10*...Another issue thats happening now is its dieseling after i shut it off.

 

Set your timing closer to 8 degrees and the dieseling will probably stop.

 

If you want to run more advance, starting at 8 degrees, try advancing it a half degree at a time and drive it around in between each adjustment. Once it starts dieseling after shut off again, back the timing down a quarter degree or so at a time until it stops and you should have the approximate point of max advance without dieseling.

 

If you want to run 10 degrees you might need to install an anti-dieseling solenoid.

 

 

Good to hear it's running better. Now you stand a chance of tracking down the various issues.

 

 

If you end up dropping your gas tank take the opportunity to replace all your rubber hoses in that area but before you install new rubber get some new, relatively supple, steel cable to run through your metal fuel lines to clear out any rust or deposits while the tank's out. Just make sure you use a longer cable than the fuel line.

 

Gently push it in one end and pull it out the other. When I did this to my '81 Hatch I think I pushed from the engine compartment and pulled from the tank end. You will probably have to twist the cable as you push it in order to get it around the bends of the fuel line, make sure you twist in the direction that tightens the braid. A little Seafoam or other cleaner will help the effort. And if you have an air compressor, definitely push some air through after the cable. Add more cleaner to the line when you air blast it.

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  • 4 weeks later...

Just a little update. Its still running the same. Surging at around 2000k even with the weber carb. Its a daily driver so i havent had the time to drop the tank and clean out the hoses. Got lots of stuff going on. The fuel filter in front remains clean and full all the time. Tried looking for vacuum leaks but havent found any. Another issue has reared its ugly head also. When i turn on the key, all the dash lights come on and stay on. They used to shut off after a few seconds after fireup, but remain on until i shut it down.:confused:

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  • 2 months later...

yes i did. Thought i posted it, but i guess i didnt. One day, i went through everything with a fine-tooth comb. Turns out that the part of wiring harness that runs across the bottom of the radiator was rubbing against the AC hardlines and exposed wires and they started shorting out and causing voltage drops. At one point, it was using the hardlines to complete the circuit somehow when i turned off the key, and would stay running even when i unhooked the battery and took it out.

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