1983 Gl Wagon EA81 with spfi & 5speed swap. I cant hold speed up hill and i have fuel cut at 5k rpm. The timing is dead on new plugs wires cap rotor. WTH is making my wagon such a gutless turd. out of all the Subaru's i have ever owned this is the only one that cuts the fuel at 5k. And the only really really gutless ea81 i've ever seen. Maybe my FPR is messed up or my fuel pump is weak? No check engine light runs great on the bottom end but top end isn't there... haha:horse: oh and my cat just stoped ratteling recently im gonna gut it and see if that helps...

I would definitely do a new fuel filter and a check the fuel pump.

Also, check your float bowl and your fuel lines at the carb, they may be

clogged slightly.

Try some seafoam through the gas tank as well, it may help.

 

Twitch

filters

Do you have plenty of fuel in the tank?

 

The lack of baffles in the tank can cause the SPFI pump to get starved during hill climbs.

 

I believe that is the problem I had on the trail right after WCSS 11

all the filters are new it does it no matter if it's full tank or 1/4 tank and its spfi not carb

Lack of fuel due to the unbaffled tank can cause problems but my experience is that as soon as the SPFI pump sucks air the engine sputters and dies. It's not so much a lack of power as it is a total shutdown till the fuel sloshes back to the pickup in the tank. I've had to pull over and let it settle down as the car just dies.

 

I think you should change the FI fuel filter if you haven't already, and check that cat to see if it's clogged. Either of those could cause some issues.

 

It wouldn't be a bad idea to invest $15 or $20 in a fuel pressure gauge so you can check that you are at 21 psi.

 

I would start there assuming you have no check engine light showing any codes.

 

Also have you checked compression on this engine recently? Always good to know the engine is mechanically sound before you start troublshooing fuel and ignition as the cause of a low-power situation.

 

GD

put a vacuum gauge on a manifold source, have a friend rev it to 2500 rpms and HOLD it there, the vacuum should drop some, but become steady. If vacuum continues to drop while doing this test, you have a restriction in the exhaust. (toasted catalytic converter, rusted out muffler baffles in the path of flow ect.) Usually the symptoms of exhaust problems will show in higher rpm ranges(higher flow) and under high load.

just installed this engine compression was even and in normal range i just forgot what readings were and it did the same thing with the prior engine i just thought it was the engine haha. I'm thinking cat is part of the reason but i can have a full tank of gas and it will still cut the fuel i have no power after about 4k which is where it builds the most power IMO... so i guess ill go through again and change the filters maybe grab a pump from the JY ... and i guess ill get a FPG tomorrow... where in the line should i put it to check fuel pressure? It will fuel cut if your going up hill, down hill, flat it doesn't matter.

 

 

Just did the vacuum test and it holds steady at 20 Inches

 

And it isn't throwing any codes and it hasn't since Ive owned it.

Edited September 30, 200916 yr by ()__1337_CRAYOLA__()>

Put the fuel pressure gauge after the filter - right before it connects to the manifold. You should see a pretty constant 21 psi. If it's low try pinching off the return line (after the regulator) - you should see it spike up to around 50 psi (only do this momentarily to get a reading). Run the engine up to 4 or 5k and see what the pressure does when you do.

 

You also might check the TPS for smooth operation up in the 4/5k range where you are experienceing problems. It could have a dead spot in it resulting in a bad reading to the ECU at the RPM you are having trouble with. It may seem like a "fuel cut" but it probably isn't.

 

GD

so everything checks out alright and today i never really rev it going to or comming from work so out of the parking lot cold it revs just fine so im think it has to do with something when the car gets up to temp maybe the FP is weak after running for an extended amount of time? is that possible or should i look somewhere elsE?

Just leave the gauge installed - zip tie it to something so it doesn't flop around. Even better if you can manage to make it readable while driving.

 

Beyond that - have you cleaned the MAF? How are the shaft bearings in the distributor? How's the spark color? Check the coil resistance values?

 

There's a number of components in the SPFI system - check each one in a systematic way. If the problem is intermittant you may have to hook up some probes in a way that will let you read voltage's and such while driving.

 

GD