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  #1  
Old 01-26-2011, 01:50 PM
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Join Date: Oct 2004
Location: Baton Rouge La
Posts: 2,632
Intermittent Fuel Pumps?

Has anyone experienced fuel pumps that are intermittent.

I am having a situation where the car will just die....and then not start for a bit.

Changed out the fuel pump relay
Changed out the OVP

I have spares of each..in fact 3 fuel pump relays.

I am wondering if one of the 2 fuel pumps is dying

Otherwise the 300ce is running like a champ. Must be a gas delivery problem.. when it dies , it dies.

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1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


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  #2  
Old 01-27-2011, 08:14 AM
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There are several ways to diagnosis,

If you have a volt/ohm/ammeter?? you can use the 10A section of the meter to watch the current draw from the pumps, about 6-8A.

IF not you can make jumper wire to by-pass the relay when the car (pumps) don't allow the engine to run.
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  #3  
Old 01-27-2011, 08:22 AM
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Join Date: Oct 2004
Location: Baton Rouge La
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Quote:
Originally Posted by mbdoc View Post
There are several ways to diagnosis,

If you have a volt/ohm/ammeter?? you can use the 10A section of the meter to watch the current draw from the pumps, about 6-8A.

IF not you can make jumper wire to by-pass the relay when the car (pumps) don't allow the engine to run.

I don't know too much about electricity. It seems maybe the ovp is sending the fuel pump relay a signal to shut down.

Maybe it's coincidence...but twice when i was stuck, i removed the ovp and the car started and i was able to get home.

so i started thinking weak fuel pumps are drawing too much sending a signal to the ovp.

maybe 22 years is the max for fuel pumps, even though the car only has 108k miles.

in the interim, i probably will have to get some banana pins and jump the relay. Fortunately, I work out of the house most of the time...
__________________
1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


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  #4  
Old 01-27-2011, 12:42 PM
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Join Date: Oct 2004
Location: Baton Rouge La
Posts: 2,632
Changed the fuel filter.....can hear pumps go on when you turn the key.

Now the car won't start.

Moving on the crank position sensor and spark
__________________
1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]

Last edited by lee polowczuk; 01-27-2011 at 03:27 PM.
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  #5  
Old 01-27-2011, 04:29 PM
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Join Date: Mar 2009
Location: Iceland
Posts: 423
I'snt the fuel pump relay just loosing the signal from the ignition switch. Try measuring the voltage from the ignition switch at the pump relay. Plug 15 if i remember right.
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  #6  
Old 01-28-2011, 07:47 AM
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Join Date: Oct 2004
Location: Baton Rouge La
Posts: 2,632
No spark....looking more and more like cps
__________________
1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


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  #7  
Old 01-30-2011, 05:12 PM
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Join Date: Oct 2004
Location: Baton Rouge La
Posts: 2,632
I replaced the crankshaft position sensor.

All is well.

First CPS to go on me in probably 6 124's.

I think it shorted out.... some bare wires at the bell housing end.

The wire was also stiff.... new one if flexible.

70 dollar fix..... took me awhile.... had to work it from the top and bottom..... made progress once I removed the oil filter.

__________________
1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]
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