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Fuel Pump Problem? and/or Suggestion for Weber


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Greetings all!

 

I have an 86 Brat EA81 with the Weber conversion from Redline. Webers been installed for about a year, and has been fine for the most part, although recently I have been getting lots of stutter and very poor MPG. Did a basic tune up with no change in performance (oil change/disty cap/rotor/pugs/cables/check idle, mixture and timing). fuel filters were changed when i put the Weber on. Ive done 3 seafoams with no change. I just installed a fuel regulator with a pressure gauge and i think my problem is too low of a fuel psi to properly feed the Weber. With the regulator set to 3psi, the meter doesn't budge from 0, and the Brat will stall shortly. If i set the regulator to the max 5.5psi, the gauge reads 2psi. Then if i give some throttle, the meter will go to 0 again and the car does seem to stutter.

 

so, i don't now how fuel pumps respond when under a load. I would think that whether your at idle or full throttle, a good pump should maintain a constant pressure. Are my symptoms those of a bad pump?

 

Has any one else with a Weber had this problem? the cause? maybe the change in carbs (from Hitachi) effected the pump because of different pressure requirements, now the old pump is tired?

 

If i were to replace the pump should I use another Subaru OEM or something else? anyone found a good replacement pump? (Ive read some threads on this, I wouldn't mind some more input)

 

Any other ideas? (no matter how ridiculous :eek:)

 

Thanks

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Did you check the pressure with out that regulator in place? The fuel pressure in your car shouldnt vary much at all. It does sound like its a bad pump. If you can source a Subaru pump that would be great they have a good lifespan, but Ive also had decent luck with the generic pumps as well. Check with ebay youll get the best price there if you can wait. Facet, Carter, Airtex, are all pretty similar pumps, just beware of no-name pumps. Also make sure if you do go aftermarket you get one with the correct psi for your weber like 2-4psi IIRC. The aftermarket pumps will require a little modification in the mounting and hose routing. Good luck!

Edited by ihscout54
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yea I was curious too about the pressure with out the regulator. Ill check soon and post. I was thinking of maybe getting a pump with a higher psi output than required, I could then use the regulator to fine tune the fuel flow.

 

Im sure i could get an OEM. Arent the oem pumps made by Kyosan Denki for subaru? I recall reading somewhere that this company also makes identical pumps for carter, essentially one in the same.

 

Thanks for the reply, ill check the un-regulated psi

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well crap! you nailed it! Stupid Spectre junk!:mad: yea with out the regulator im getting 3-4psi constant at idle or full throttle. I guess I got ahead of my self getting the regulator in the fuel line, hopefully the Spectre psi gauge is of "OK" quality, cause thats what im using.

 

Well I guess that is that. My second suspect was the distributor (shaft and all) as it is the last thing that has not been replaced recently. With the Weber I was able to remove a lot of potential problems, the engine is a fairly recent rebuild from CCR, the ignition solenoid has been replaced, im getting good spark, muffler & catalytic converter replaced with in 2 years. Im not really sure how to test the distributor as my problems, seem to be when accelerating and crusing in 2-4k rpm range.

 

any thoughts? Thanks

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have an 86 Brat EA81 with the Weber conversion from Redline. Webers been installed for about a year, and has been fine for the most part, although recently I have been getting lots of stutter and very poor MPG

Have you inspected your choke? You also should be doing a thorough inspection of your vac. system, inluding the throttle shafts and carb base. The adaptor and gaskets from redline arent so hot from what I hear.

My second suspect was the distributor (shaft and all) as it is the last thing that has not been replaced recently.

Thats easy, try and wiggle the rotor/shaft, it should have very little play. Usually when problems begin the tach gets jumpy too. Is your vacuume advance working?

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I just installed a used disty and there is certainly improvement. the old disty did seem to have some play up and down, as well as right to left in its shaft, the used one has noticeably less play than the old one. The vac advance seems to be working, im just messing with some adjustments with the timing/idle/mix right now.

 

the jerkyness on acceleration seems to be gone, but im still getting a hint of it while cruzing in the 2-4k range. also a noticeable boost in take offs from a stop.

 

I have been reading some other posts and I see that some who have done the Weber swap have also removed the EGR valve and installed a plate there. I still have the value there, But I guess its really not needed any longer?

 

Hatchsub: thanks for the offer, but I think I might stay un-regulated for now. The PSI seems to be stable. I do appreciate the offer though! Thanks!:)

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I've never needed a regulator of any kind with the Weber's. Typically the common cheap regulators need 10+ psi on the high side to work at all. I've used Subaru SPFI pump's on Weber's with a regulator. 50 psi down to 3 psi at the carb.

 

Leave the EGR and hook it to the late ported vacuum port on the front of the Weber (if it's a newer one, the port will be blocked with a small brass screw).

 

GD

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ok thanks GD, thats how its set up now, so I guessed right on that.

 

Well.....I think I found the problem....Do they sell new engines in a bottle?

 

I took compression readings, and im not sure what is the norm, but these dont sound good.

 

Cylinder#:

1 - 125 psi

2 - 85 psi:horse:

3 - 135 psi

4 - 115 psi

 

Tell me the secret fix for this, or just make up one.

 

Thoughts?

 

Thanks

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Tell me the secret fix for this, or just make up one.

 

Thoughts?

 

That doesn't tell you much. It just tells you to run a leak-down test to determine the real problem.

 

Be sure you are running the test properly..... disconnect fuel pump, run till the engine stops, all plugs out, throttle fully open, crank for 5 comp. strokes of the cylinder being tested.....

 

GD

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Ok I retested the compression. my 1st problem is that I didnt take out all the spark plugs the 1st time. Although cylinder #2 is still lower than the rest (120psi) the other 3 read between 155 & 175psi (much better). Something else I noticed was my #4 newly installed spark plug was caked with oil, so was the old spark plug. Thats 2 cylinders on the drivers side both showing some problems.

 

I didnt get to a leak down test, getting a tester is easy (pretty cheap to rent or buy), but I dont have a shop compressor and it looks like renting one would start to cost some $$ - I may just have a shop do the test for me, but Im not sure if I need one, im kinda thinking I dont as there is definitely something fishy on the drivers side cylinders. Im going to open up the EA81 and rebuild it again myself (Im strapped for cash). The engine was rebuilt like 2 years ago, and I only have like 10K on it if that. Im not sure why this would happen.

 

Ill prob. just try to find a used one to put in for now, Then I can work on the one thats currently in the car at my own pace. I cant standing driving this thing, its like ridding with some one who's learing to drive a manual transmission - so jerky!

 

Ive never rebuilt an engine before, but im mechanically inclined, and willing. Any rookie Mistakes I should watch out for?

 

Thanks again for your help.

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I dont know what CCRs 3 year warranty coverage details are, but if you bought this from them you need to contact them. I would take it in and pay for the test so you have documentation of the problem and perhapse the mechanic can give you his opinion of exactly whats wrong. I would also take pictures and have complete log of what is going on. I have read nothing but good things about them and I have no doubt they will assist you in any way they can. Your probably under warranty still.

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This engine I have now is the warranty engine. The 1st engine I got from CCR arrived beat up. Had a smashed in oil pan and dinged up valve covers (im assuming caused by shipping), CCR said it would be "fine", but it never ran right. After had it for about 2.5 years and like 25 or 30K on it (something like that, all off the top of my head) and it was determined to have something wrong with the valves, not to mention it was sucking a lot of oil into the engine through the cover vents. It was returned under warranty and this one thats in the Brat now is the one that was sent to me from CCR.

 

They seem to be nice people, but Im not sure if they warrant a warranty engine. That seems like a lot to ask.

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How is your PCV routed with the Weber? I suspect you aren't getting rid of acidic blow-by gasses properly and it may be leading to cylinder damage. The #2 and #4 cylinder are on the downstream side of the PCV and also your comment about sucking oil out of the valve covers gives me cause to wonder how it's setup.

 

GD

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The problem I was referring to with the oil in the intake was with the 1st engine, not this engine currently installed. The 1st engine had the stock setup with the Hitachi and all the emissions control stuff. When it was all switched over to the 2nd engine (current install), the oil in the intake issue was completely gone.

 

The current weber setup also has no problems with oil vapor, always clean in the Weber's filter housing so is the PCV. Current set up with the Weber: I have a valve cover filter on the "in" side (passenger) and on the "out" side (driver) an oil catch can T'd in with the PCV and the Webers filter.

 

Sorry for the confusion

 

Thanks

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Unfortunately I suspected your PCV was setup something like that. In order to get positive flow and thus remove blow-by gasses from the crankcase, you need to have the passenger side open to the/an air filter (valve cover filter is fine), and the driver's side must go directly to the PCV valve. If the driver's side is also open to atmosphere as you have it currently, there will be no positive flow as there will be no pressure differential between the two valve cover's. The gasses in the crankcase must be displaced by a positive flow from one valve cover to the other - that cannot take place if there is no pressure differential.... do you see how there cannot be a pressure differential with your current sytem? Both ports are open to the atmosphere with the same diameter lines.....

 

On the stock system there is only a 1/4" ID hose T'd into the driver's side and running to the filter - this is an "orifice" to control the flow and prevent oil from being sucked out of the driver's side valve cover.

 

Several years of running without removing any acidic blow-by may be causeing damage to the engine's and thus your low compression, etc.

 

GD

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Dont just give in, I personally see where you are coming from. I have never had good luck with any "shop" re-man engine or carb. Unless you feel you are at fault in some way for the engines issues Ide be on the phone. Rebuilding is not cheap or easy. If you want the experiance then find a core to rebuild, but call CCR, maybe they will help you. I also think you should try to get the PCV system as close to stock as possible, even if you just used a "T". It may take a little work and modification to the air box but its probably better than your current setup.

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yea, Im thinking about it. I really dont think its anything I did. I always let it warm up, I dont drive it hard or anything, just trips around town. Kept the oil clean, etc. On one hand I wouldnt mind the experience of a rebuild. Im just not 100% sure how to handle it yet. The engine has certainly never lived up to its name yet. I guess it couldnt hurt to call them anyway.

 

With the PVC are you talking like taking it out if the "t" and just giving it its own hose straight to the filter box?

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With the PVC are you talking like taking it out if the "t" and just giving it its own hose straight to the filter box?

 

GD always has what ya need when ya need it. :banana:

The pics show exactly what I was thinking in reguards to "just using a T". If you get another stock driver side "T" and fit it just like the pic shows it would be perfect. I personally would pref. having another hole in the box but this would work just fine and is cheaper, easier, and better than what your setup involved.

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Wow, what service! thats essentially how I have it, The only difference is I have a valve cover filter on the passenger side, and I added a catch can on the drivers side. The drivers side is not exposed to the atmosphere. I thought you needed that fresh air flow entering the passenger side and exiting the drivers side though the crank case.

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