courtwarren Posted April 2, 2015 Share Posted April 2, 2015 I have 85 brat got a couple months ago,been working on it ever since.It starts right up runs pretty good,I can drive it 5 miles or 50,But when I shut it off, run in store or what ever, get back start it up it idles fine - so as you put power to it it wants to die push gas pedal a little more ( or feather the pedal )you can get higher rpms to get it to go. Then using clutch as to get it going much like a bucking bronco,Drive a little maybe a few miles it goes through the flat spot an in to higher rpm an all of the sudden it starts running fine again??? have removed tank cleaned an sealed new filters-had carb rebuilt ,new cap rotor- module- wires- plugs-egr-pcv-coil-?timed-not running hot So What have I missed? So far it has always started fine and runs good UNTIL I stop and then want to go again. Quote Link to comment Share on other sites More sharing options...
DaveT Posted April 3, 2015 Share Posted April 3, 2015 Check that all the duel, vapor recovery, lines and vent are clear. T a fuel pressure gauge into the line. 1 Quote Link to comment Share on other sites More sharing options...
jonas Posted April 3, 2015 Share Posted April 3, 2015 You running stock Hitachi? 1 Quote Link to comment Share on other sites More sharing options...
skishop69 Posted April 3, 2015 Share Posted April 3, 2015 +1 for Jonas. If you're running the Hitachi, it's probably got some crap in the float bowl or something is leaking. It's going to be fuel related, not spark. You might have bad windings in the fuel pump as well. Keep it moving and you're all good. Shut her down and let her heat soak and the pump goes crap til it cools down. Seen that before too though not on a Subie. 1 Quote Link to comment Share on other sites More sharing options...
SubieBrat Posted April 3, 2015 Share Posted April 3, 2015 id say upgrade time my hitachi did the same thing. went weber and never looked back.... then the motor gave six months later.... <_> Quote Link to comment Share on other sites More sharing options...
jonas Posted April 3, 2015 Share Posted April 3, 2015 (edited) can you hear the fuel pump kick on when you turn the key on? You should hear a short burst. I haven't crawled under my brat for some time but I think there is a filter located next to the pump as well. Edited April 3, 2015 by jonas Quote Link to comment Share on other sites More sharing options...
Dinky26 Posted April 3, 2015 Share Posted April 3, 2015 can you hear the fuel pump kick on when you turn the key on? You should hear a short burst. I haven't crawled under my brat for some time but I think there is a filter located next to the pump as well. +1 For the filter by the pump inside the rail behind cab on drivers side. Junk in the pump maybe. 1 Quote Link to comment Share on other sites More sharing options...
el_freddo Posted April 3, 2015 Share Posted April 3, 2015 Also try blowing compressed air through the fuel line. Then clean the tank out again. CheersBennie Quote Link to comment Share on other sites More sharing options...
courtwarren Posted April 3, 2015 Author Share Posted April 3, 2015 I did clean out lines when I did fuel tank New filters before putting the Hitachi carb back on---I will redo all lines, and I'm liking theory of of bad windings something is getting hot or hotter when first shut down and then after running for a short time seems to want to run like nothing ever happened. like a opened minded girl friend thanks for all the help everyone.Court Quote Link to comment Share on other sites More sharing options...
naru Posted April 3, 2015 Share Posted April 3, 2015 Forget about the fuel pump,filters and lines. You are barking up the wrong tree with those. Your car has a carburetor. It was full of fuel when you parked and it was still full after sitting. You could UNPLUG the fuel pump and the car would still run normally for a short time. EA-81 carbs have a fuel level sight glass. As long as fuel is in the middle,you can forget about fuel delivery(to the carb) issues and move on. I have experienced the same symptoms as you. It was related to the 2 port underhood temperature switch mounted on a standoff on the intake near the EGR. I could cure it by pouring a little water over the sensor when leaving. Heat soak opens the valve while you are parked. There is probably a vacuum leak or missing inline orfice upstream. A quick and dirty "fix" would be to block the vacuum line between the valve and the intake. I think a lot of hitachi carb problems are really emission component problems. Weber swaps eliminate them because they delete many emission components. Keep us posted. 2 Quote Link to comment Share on other sites More sharing options...
courtwarren Posted April 5, 2015 Author Share Posted April 5, 2015 spend the day off an on replacing hoses then some more hoses and clamps ,then drove it to parts store to get more hose,ran like crap all the way up an back-finished plumbing and went for another drive it was a quite nice drive, thinking needs to have that two port heat sensor replaced let it sit about 20 mins whet back out a started it and it s doing same as before?I can try the quick an dirty tomorrow see how that goes? Quote Link to comment Share on other sites More sharing options...
naru Posted April 5, 2015 Share Posted April 5, 2015 Did you pour some water on it as a diagnostic experiment? It is unlikely the sensor itself is faulty. Quote Link to comment Share on other sites More sharing options...
that one kid Posted April 5, 2015 Share Posted April 5, 2015 "bucking bronco" exact term I would have used to describe my brat before the weber swap Quote Link to comment Share on other sites More sharing options...
jono Posted April 5, 2015 Share Posted April 5, 2015 wonder if you tried fitting in tiny water irrigation taps in the vac lines off that port sensor things lines so you can over ride its function with a twist of a tap and change your performance ? Quote Link to comment Share on other sites More sharing options...
courtwarren Posted April 6, 2015 Author Share Posted April 6, 2015 tried the water over- about 5 times now,works everytime?Thank you So whats next oh wise one? Quote Link to comment Share on other sites More sharing options...
naru Posted April 6, 2015 Share Posted April 6, 2015 You could cap the output port and be done with it or you could look for the upstream problem. Not all that hard. It will be a bad diaphram in the 2 port vacuum switching valve or the 5 port air contol valve. If neither of those then it might be that the inline restriction orfices are miising from one of the 2 hoses between the air control valve and the carb. Both should have .022 inch.restrictors.Little brass jobbies I think.Easy to miss when replacing vacuum lines. Try blowing thru those lines. You could possibly make some or snag an original line w/the orfice from the wreckers. Another possibility is that all of the above are OK,but,the carb is marginaly lean already and the control valve leaning it out a little more by opening the air bleeds at high underhood temps pushes it over the edge. Carb cleaning or general vacuum leak reapair required. My money is on missing orifices. Quote Link to comment Share on other sites More sharing options...
courtwarren Posted April 6, 2015 Author Share Posted April 6, 2015 You could cap the output port and be done with it or you could look for the upstream problem. Not all that hard. It will be a bad diaphram in the 2 port vacuum switching valve or the 5 port air contol valve. If neither of those then it might be that the inline restriction orfices are miising from one of the 2 hoses between the air control valve and the carb. Both should have .022 inch.restrictors.Little brass jobbies I think.Easy to miss when replacing vacuum lines. Try blowing thru those lines. You could possibly make some or snag an original line w/the orfice from the wreckers. Another possibility is that all of the above are OK,but,the carb is marginaly lean already and the control valve leaning it out a little more by opening the air bleeds at high underhood temps pushes it over the edge. Carb cleaning or general vacuum leak reapair required. My money is on missing orifices. thank you for your time, the help is very much appreciated wish I would have asked for help many headaches an dollars ago,hard to do when your convinced the next fix will be the one.Also makes it harder for me -trying to keep it as it was built.Have no problem with a carb thats worked 30+years 10s of millions of miles very humbling this little brat, 1 Quote Link to comment Share on other sites More sharing options...
courtwarren Posted April 9, 2015 Author Share Posted April 9, 2015 Found two very short vac hose's that I had past up on earlier guest's.Went through- every - thing one more time vacuum switches ,found restrictors in tacked , in tees ? And so far so good,Very good THANK YOU ALL AGAIN dont think you can beat this site for information and help some times hard to relay a problem( 4 me anyway ) Quote Link to comment Share on other sites More sharing options...
naru Posted April 11, 2015 Share Posted April 11, 2015 Another possibility is that all of the above are OK,but,the carb is marginaly lean already and the control valve leaning it out a little more by opening the air bleeds at high underhood temps pushes it over the edge. If so,I`d be looking at the altitude compensator. It controls the air bleeds as well. It might be open too wide. It should be closed at low altitude. Try blocking it. Quote Link to comment Share on other sites More sharing options...
courtwarren Posted April 16, 2015 Author Share Posted April 16, 2015 Okay all hose has been replaced,then blocked off altitude compensator,And it restarts and runs pretty good even after driving and getting up temp and shutting down, when before on restart it it would not unless cooled down with water or time. But now third gear at about 50 to 55-3K on tack it acts as if its running out of fuel 55 down to 50 then back again over and over, not wanting to go above that . Cant go fast enough in 4th to get it to do again,not doing it in second at same rpm So now what? Quote Link to comment Share on other sites More sharing options...
naru Posted April 16, 2015 Share Posted April 16, 2015 3rd gear weirdness only w/the altitude compensator blocked? Maybe it needs to be open a little. What is your altitude? I don`t think it is your problem,but,I would make sure the fuel level is correct by shutting the car off w/it behaves badly, coasting to a stop and examining the carb sight glass. Quote Link to comment Share on other sites More sharing options...
courtwarren Posted April 17, 2015 Author Share Posted April 17, 2015 Just had carb rebuilt called an talked to rebuilder about above condition of brat,he said same thing about blocking alt-comp and said very doubtful that it was running short of gas that even if gas is at bottom of glass an just visible,that the jet is in very bottom and would have more than enough to run as it should,he didnt ask about altitude though?That is about 1750 feet? He did say somthing about rejetting the carb as it was all back to stock specks at rebuild,saying maybe the thing to do because of it being a high milage rig,didn't think that 300K was to high for a subaru It sure runs good, until it doesn't I will try running and shutting it down at just that point of weakness it jumps back an forth fairly quickly . thank you Quote Link to comment Share on other sites More sharing options...
naru Posted April 17, 2015 Share Posted April 17, 2015 I`ll ask again. 3rd gear weirdness only w/the altitude compensator blocked? I don`t think your rebuilder knows what he is talking about. Has he ever run a carb w/the fuel level at the bottom of the sight glass? I have. They don`t run very well. Makes me question the quality of your rebuild. Changed the jets? Scary! I do not think there is a fuel level problem either,but,I would check. I suspect you are running a little rich w/the compensator blocked. 3rd gear is different from 2nd at the same rpm because there is more airflow(throttle open more) The air bleeds that the compensator and orfices feed have more effect at higher flow rates. There are not a lt of specs for the compensator. Closed at low altitude and opens at some unspecified point. I suspect it needs to be open a little at 1750 feet.Maybe yours opens too wide too soon. Compare it to others. I would try some junkyard ones and maybe experiment w/different orfices(valve?) inline 1 Quote Link to comment Share on other sites More sharing options...
courtwarren Posted April 17, 2015 Author Share Posted April 17, 2015 Thank You will keep trying. Quote Link to comment Share on other sites More sharing options...
courtwarren Posted April 19, 2015 Author Share Posted April 19, 2015 3rd gear weirdness only when blocked yes Quote Link to comment Share on other sites More sharing options...
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