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Bad accumulator?

Thanks again for the help with the dizzy vacuum guys, I have one other issue maybe someone can help with. Recently I have noticed that the fuel pumps come on with the key in the on position but not started, this does not happen all the time, and there is no pattern. More often than not it happens when the car has been sitting, but ocassionally with a warmed up engine as well. The fuel pumps make some noise, but to my ear they don't exactly sound sick maybe they are. The car starts fine and idles fine (co set 3% idle o2 sensor disconnected) AFRs are too rich across the board 10 or so on boost with the cloud of smoke when I really get on it. The green connection behind the CIS flapper is secure. The engine feels very labored when revved above 4000 rpm, and when cruising off boost on the freeway at 80mph or so it feels like it is working too hard, like I am towing a boat or something. I have ordered the CIS test guage from our host. does this sound like low fuel pressure to you guys? Will a bad accumulator give you problems while running, or just starting problems? Also what all do I need to test the CIS, I saw that I need some kind of hand pump with a guage to pressurize the WUR for testing, can I get this at the auto parts store, or is this another special tool? This is on an 87 with a 1bar spring and muffler only.

Again, thanks for the help guys,

Eric
Old 09-15-2007, 09:30 AM
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As soon as I turn my key to the run position, I hear the high pitched sound of the fuel pumps. They stay on until I turn the key to the off position. Made me a little nervous when I was rewiring the electrical stuff to have them running but all seems to have turned out okay.
Have you changed your fuel filter recently?
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Old 09-16-2007, 05:28 AM
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I bet that is not your fuel pumps you can hear but the CDI box.
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1981 UK 930. G50/01 shortened, 964 3.8RS Fibreglass Body Kit, 18" Alloys 8.5" F & 10" R, 225's F & 285's R, Special Colour Metallic Blue Paint, FIA Sparco Evo's, A/C and Air Pump removed, Electronic Boost Controller, GHL Headers, Tial46 WG.
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Old 09-16-2007, 06:53 AM
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Ahh... good point. I bet you are correct! Duh... I should have paid better attention when hunting for the sound.
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Old 09-16-2007, 07:38 AM
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The high pitched whine you hear when you turn the key is the cd box. Sound can be traced back to the engine compartment. Also, make sure that the whine is heard for about 5 seconds after shutting off the ignition, this allows spark to burn off unburned fuel in the system after the engine has stopped. This is a quirk to the turbo engines.
The fuel pumps should not run until the engine is actually turning. there is a switch on the CIS air meter plate that governs this....also incorporated into the fuel pump relay circuit. Otherwise you will flood the non running engine if they run all the time.
good luck.

Fred
Old 09-17-2007, 09:22 AM
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Quote:
Originally Posted by fredmeister View Post
Otherwise you will flood the non running engine if they run all the time.
good luck.

Fred
I used to think this too, but have since learned that the injectors don't actually deliver fuel to the combustion chamber unless the flapper in the metering housing is also pressed. Which makes sense, because when you perform CIS fuel system pressure tests, you need to be running the fuel pumps when the gauges are connected, however, the engine doesn't flood because you aren't typically pressing the flapper during these tests...the fuel just returns to the gas tank.
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Old 09-17-2007, 09:48 AM
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Running rich will make your engine less responsive. Be sure to change your oil often until that is corrected.
The pressure device you speek of is to test the boost enrichment function of the WUR. That does not sound like your problem.
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Old 09-17-2007, 09:58 AM
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Thanks guys, I am saying that in addition to the cd box the pumps also run sometimes with the ignition in the on position, but engine not running. trying to figure out the cause for the symptoms above, later today I will check fuel delivery from pumps. If I read correctly about a half liter in 30 seconds. I am awaiting delivery of the CIS test guages. I am still trying to get my hands on the factory workshop manual. last one I saw on Ebay someone outbid me, and that was on a copy of the manual. I guess I will just have to shell out the 400 bucks for a new one. 400 will buy quite a few parts for a 930.
Thanks again
Eric
Old 09-17-2007, 10:26 AM
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Oops, I meant 1.16 liter in 30 seconds. 1170cc/hr = 1.16l/30 secs. Good thing modern airline pilots don't have to do much math

Eric
Old 09-17-2007, 10:56 AM
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Well fuel delivery seems to be fine, pumps produce over 1.2 liters in 30 seconds. what now? Can't figure out why pumps will run with ignition in on with engine not running

Eric
Old 09-17-2007, 06:56 PM
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Could be that they are wired that way (mine are) or that your 20 year old ignition switch is sharing detents.
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Old 09-17-2007, 07:22 PM
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Well I don't think they are wired that way, because sometimes they run sometimes they don't, there really isn't a pattern.

Another thing I found tonight, was the AAR seems to be leaking when the engine is warm. The resistance at the terminals is 20 ohms, whatever that means. I think it should be around 33. I suspected something might be wrong with it since I no longer get the high idle at start-up that settles to normal idle. I found that if I plug both the AAR outlet and the IC outlet to the AAR the engine idles 200rpm lower. This suggests some unmetered air going through the system. Could this be causing me some of my troubles? or is 200rpm not significant enough of a leak to be concerned with on CIS?

Eric

87 930

Last edited by e170drvr; 09-17-2007 at 10:03 PM..
Old 09-17-2007, 10:00 PM
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Hey Rarly, I noticed in another thread that you removed the AAR. Do you ever have trouble starting it up when it is cold?

Eric

87 930
Old 09-17-2007, 10:22 PM
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Quote:
Originally Posted by e170drvr View Post
Hey Rarly, I noticed in another thread that you removed the AAR. Do you ever have trouble starting it up when it is cold?

Eric

87 930
I don't have one either. Mine appeared to be working fine, I just pulled it off for *****s and giggles...can't stand clutter. Car starts right up, but the idle is a tad low for a few moments. I think the early Turbo cars had a hand throttle for cold morning starts. Usually by the time I go one or two blocks in my neighborhood, the idle is normal, and no hot start issues to report, either.
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Old 09-18-2007, 01:07 AM
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Old 09-18-2007, 01:08 AM
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You can replace the AAV with your right foot. It doesn't do anything until after the engine starts.

Your AAV may be leaking a bit but won't cause the symptoms you describe. Fuel system pressure readings and A/F ratio numbers are needed to help shed light on things.
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Old 09-18-2007, 05:22 AM
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Yeah, Will have to wait until the guages show up to figure this out. car runs horrible right now, and seems to be getting worse. Feels like the car isn't getting any gas. If the fuel delivery from the pumps check out, would it be safe to rule out the pumps, or could it be that I still don't get adequate pressure from them?

Thanks fellas,
Eric

87 930
Old 09-18-2007, 06:17 AM
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Ok, just got some new information. The pumps on my 87 should be delivering 1500cc per 30 seconds not 1170. I measured it several times, and I am getting around 1300. This would have been within spec for an older car but just under for 87 spec. Would this contribute to my car running poorly, or is it close enough to not matter much. (I am still waiting for the CIS test kit to check the rest) Also, is there any other way to check pump pressure, than the cis test kit and the other adapter (that I don't have) that attaches to the tester? Maybe hook up a meter to the fuel return line and remove the pump relays one at a time?

Thanks
Eric
87 930
Old 09-19-2007, 09:40 AM
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