1957 Cadillac Almost Didn't make it home (Car Running Real Rough)

[Bill Balkie 24172]

Hello,
I hope someone can help . I went for a 100 mile drive today in my 1957 Seville . About 65 miles into my trip i noticed the Fuel gage acting irratically . Jumping from normal to being pinned on full  At the same time the car lost most  power as if it was running out of gas . I know i had a half a tank so that could not be the problem . I cound not do over 20 mile an hour .When the fuel gage acted up so did the Engine . I stopped the car looked at the Fuel filter and it was full and looked  fine . I reaved the engine and it seamed to be ok . continued on my way and the same thing happened . I limped home at 20 miles an hour , but i did makre it home . The confusing thing is this must be tied in with the fuel gage leading me to thing this is electrictical . Could  it be i need a voltage regulator . Any help would be greatly appreaciated . thanks Bill

[homeonprunehill]

Hello,
I hope someone can help . I went for a 100 mile drive today in my 1957 Seville . About 65 miles into my trip i noticed the Fuel gage acting irratically . Jumping from normal to being pinned on full  At the same time the car lost most  power as if it was running out of gas . I know i had a half a tank so that could not be the problem . I cound not do over 20 mile an hour .When the fuel gage acted up so did the Engine . I stopped the car looked at the Fuel filter and it was full and looked  fine . I reaved the engine and it seamed to be ok . continued on my way and the same thing happened . I limped home at 20 miles an hour , but i did makre it home . The confusing thing is this must be tied in with the fuel gage leading me to thing this is electrictical . Could  it be i need a voltage regulator . Any help would be greatly appreaciated . thanks Bill
[/quote
02-16-08
BILL,I feel the problem is somehow connected (electricly) to the fuel gage. It is impossible to trouble-shoot without a wireing diagram. I would say at this time that the voltage  reguartor IS not the problem.
Good Luck,JIM

[Glen]

I agree this is not a fuel problem.  The sender for the fuel gage is in the tank and would not reflect problems in the fuel line such as plugged filters. 

Years ago my sister had a problem with a rough running engine when under load.  It turned out to be a bad regulator that tried to charge the battery to a very high voltage.  I seem to remember it was running about 60 volts or something like that.  The engine ran fine at low RPM because the alternator was not turning fast enough to generate much voltage.  The generators of the 50s could put out over 100 volts if the field was tied directly to the battery.  This can be checked with a voltmeter on the output of the generator. 

Another possibility is a bad ground.  Check the ground straps to the engine.  There are a number of strange things that can happen with bad grounds. 

Glen

[Bill Balkie 24172]

Thanks Glen, Today i will Check all my filters , , disconnect my lead from the fuel gage then check out my Engine ground straps , That could be a good possibility , because i just had the engine rebuilt . Thanks alot Glen for your help ...Bill

I agree this is not a fuel problem.  The sender for the fuel gage is in the tank and would not reflect problems in the fuel line such as plugged filters. 

Years ago my sister had a problem with a rough running engine when under load.  It turned out to be a bad regulator that tried to charge the battery to a very high voltage.  I seem to remember it was running about 60 volts or something like that.  The engine ran fine at low RPM because the alternator was not turning fast enough to generate much voltage.  The generators of the 50s could put out over 100 volts if the field was tied directly to the battery.  This can be checked with a voltmeter on the output of the generator. 

Another possibility is a bad ground.  Check the ground straps to the engine.  There are a number of strange things that can happen with bad grounds. 

Glen

[Bill Balkie 24172]

Jim, Thanks for your help , Today i am going to disconnect the fuel gage and check for a loose ground strap . Also check all the fuel filters . Thanks jim for your Help .  Bill

Hello,
I hope someone can help . I went for a 100 mile drive today in my 1957 Seville . About 65 miles into my trip i noticed the Fuel gage acting irratically . Jumping from normal to being pinned on full  At the same time the car lost most  power as if it was running out of gas . I know i had a half a tank so that could not be the problem . I cound not do over 20 mile an hour .When the fuel gage acted up so did the Engine . I stopped the car looked at the Fuel filter and it was full and looked  fine . I reaved the engine and it seamed to be ok . continued on my way and the same thing happened . I limped home at 20 miles an hour , but i did makre it home . The confusing thing is this must be tied in with the fuel gage leading me to thing this is electrictical . Could  it be i need a voltage regulator . Any help would be greatly appreaciated . thanks Bill
[/quote
02-16-08
BILL,I feel the problem is somehow connected (electricly) to the fuel gage. It is impossible to trouble-shoot without a wireing diagram. I would say at this time that the voltage  reguartor IS not the problem.
Good Luck,JIM

[walt chomosh #23510]

Bill,
  My 55 barely made it home one night.....the crud in the gas tank clogged its outlet so bad that I couldn't even push a coat hanger thru it! The motor would idle all right,but had no power to move the beast.(in my case,I totally opened up the tank,cleaned,and welded back)(don't try doing this at home without taking extreme precautions!). ....walt...tulsa,ok

[Bill Balkie 24172]

Hello Walt ,
Thanks for your email , I got up early this morning , and took the car for a ride again , Same thing Happened .   My see thru fuel filter was half full and every now and then a bubble or two would form . So I hook up a electric fuel pump and the car ran super strong . The fuel gage still was bouncing around , but it did run very strong and the fuel filter was full of fuel . Walt ,I purchased a fuel pump from Coppers  vintage auto parts in California back in August  . It only lasted for a few Hundred  miles . so I purchased another and this one only lasted for a few hundred miles . These pumps cost  50.00 . They do not look like the original pump for the 57 Cadillac . The original pumps had a round dome on the top . not sure about 1956 .I have the original fuel pump ,  So I purchased a rebuild kit for the original pump . It should be here this week . I am going to rebuild the original pump and install it next week. Mean while I still  have the electric as a back up . Walt I add an additive to my Gasoline  because I do not have hardened valve seats , do you think this additive is the cause for the fuel pumps dyeing  in such a short time ? Getting back to the fuel gage . i think when the tank approaches a 1/4  the sender  must have a dead spot or a short . It is ok as long as the tank is At least 1/2 full . Thanks Bill

Bill,
  My 55 barely made it home one night.....the crud in the gas tank clogged its outlet so bad that I couldn't even push a coat hanger thru it! The motor would idle all right,but had no power to move the beast.(in my case,I totally opened up the tank,cleaned,and welded back)(don't try doing this at home without taking extreme precautions!). ....walt...tulsa,ok

[35-709]

I cannot answer the question as to whether the fuel additive is causing your premature pump failures.  But it has been pretty much accepted for a long time now that other than in engines being used for high output conditions such as racing or marine use, hardened valve seats or additives to "protect" them are unnecessary.  Sure, if the engine is being overhauled, put them in, otherwise do not worry about it.  The type of driving you do with your '57 does not require hardened seats.

[Bill Balkie 24172]

Geoff  Thanks for that advice . i will stop using the additive and install a filter before and after the Fuel Pump 

I cannot answer the question as to whether the fuel additive is causing your premature pump failures.  But it has been pretty much accepted for a long time now that other than in engines being used for high output conditions such as racing or marine use, hardened valve seats or additives to "protect" them are unnecessary.  Sure, if the engine is being overhauled, put them in, otherwise do not worry about it.  The type of driving you do with your '57 does not require hardened seats.