Author Topic: Car won't start. Fuel problem?  (Read 1917 times)

Offline Rick Biarritz

  • Posts: 303
  • Name: R. Ould
Car won't start. Fuel problem?
« on: December 09, 2012, 08:09:38 AM »
My 83 Eldo with the 4.1 has a new battery, alternator, and starter. All put on 2 weeks ago. All was fine until an hour ago. It cranks long and hard and strong, but won't start. Fuel issue?

Thanks

Offline Rick Biarritz

  • Posts: 303
  • Name: R. Ould
Re: Car won't start. Fuel problem?
« Reply #1 on: December 09, 2012, 09:19:16 AM »
If it was loose electrical, would it crank strong?

Offline Dave Shepherd

  • Posts: 1748
Re: Car won't start. Fuel problem?
« Reply #2 on: December 09, 2012, 09:46:45 AM »
Basics here, take the air cleaner off, see if the injectors are spraying when cranking, if not check the fuel pump fuse/injector fuses., if ok check loose connections at the fp relay, and power to the fuel pump, see if the injectors have 12v to the power side of the injector connectors, with the key on. Post back results.

Offline TJ Hopland

  • Posts: 4157
Re: Car won't start. Fuel problem?
« Reply #3 on: December 09, 2012, 09:53:50 AM »
On these fuel is easy to check, just take the lid off the air cleaner and look for fuel coming out the injectors when someone cranks it.  The fuel should coming out in a slightly pulsed Asian fan like mist.  With this system if there is anything dribbling out at all it would at least occasionally fire.  If there is no fuel then there are 2 options, fuel pump or the system does not know the engine is turning and needs fuel.   First test for the fuel pump is to have someone go near the back of the car and have someone turn they key to run.  The fuel pump should run for a few seconds when the key is first turned on and then also when the engine is running or cranking.  Its usually hard to hear them over the other engine noises.   No noise then the pump is not running.    If you do hear it next you would want to go back up to the engine and try and determine if you can hear the injectors clicking when the engine cranks.  Again its sort of hard to pick that sound out with the other noise but you can hear them.  My guess is if you hear the fuel pump but are not getting fuel you wont hear the injectors clicking. 

This pretty much covers the fuel side of things.  Next is spark (which is where the fuel gets triggered from).     Pull a spark plug wire and ideally using a spark tester or old spark plug laid on a good ground and crank to see if you are getting spark.   On newer engines you dont really want to just hold the wire near ground, the spark jumping that far can cause bad things to happen to electronics.   If you don't have spark next I would pull the distributor cap and make sure the rotor is actually turning.   Let us know if you get that far and we can go over more ignition testing if needed. 
StPaul/Mpls, MN USA

73 Eldo convert w/aftermarket EFI
75 Eldo rusty but trusty
80 Eldo Diesel
And other assorted stuff I keep buying for some reason

Offline 76eldo

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      CLC Member #22443
  • Name: Brian Rachlin
Re: Car won't start. Fuel problem?
« Reply #4 on: December 09, 2012, 08:51:51 PM »
Check for fuel as above, and for spark.

The ignition module in the distributor may be bad.

Brian
Brian Rachlin
Huntingdon Valley, Pa
CLC # 22443

Lifelong Cadillac Enthusiast
Currently own several Cadillacs
ranging from 1960 to 2007

Offline TJ Hopland

  • Posts: 4157
Re: Car won't start. Fuel problem?
« Reply #5 on: December 11, 2012, 09:07:16 PM »
Good to hear you have had good luck with new replacement electronics parts for the 80's cars, I have found the new stuff to be junk.  I now keep an eye out for original stuff when I am in the junkyards.  If you are talking about the original 75-80ish 4 pin HEI module then yes there are some decent 'high performance' options out there but once you get to the computer stuff its just the standard replacement stuff which tends to be the low quality junk. 

If the ignition module is dead you usually will not get fuel either since the module is what sends the signal to the computer to tell it the engine is turning.   
StPaul/Mpls, MN USA

73 Eldo convert w/aftermarket EFI
75 Eldo rusty but trusty
80 Eldo Diesel
And other assorted stuff I keep buying for some reason

Offline Guidematic

  • CLC# 19186
  • Posts: 879
  • Name: M. Jones
Re: Car won't start. Fuel problem?
« Reply #6 on: December 12, 2012, 10:20:16 AM »

 As far as I know, Pertronix sells systems to retrofit points only. This car was originally equipped with HEI which is better than Pertronix.

 Again, check the basics. Fuel and spark. And check the fuses first if the injectors are not firing.

 Mike
1970 Fleetwood Brougham 68169
1985 Eldorado Coupe 6EL57
1988 Eldorado Biarritz 6EL57
1990 Brougham d'Elegance 6DW69
1994 Fleetwood Brougham 6DW69

Offline Dave Shepherd

  • Posts: 1748
Re: Car won't start. Fuel problem?
« Reply #7 on: December 12, 2012, 01:05:06 PM »
As far as I know, Pertronix sells systems to retrofit points only. This car was originally equipped with HEI which is better than Pertronix.

 Again, check the basics. Fuel and spark. And check the fuses first if the injectors are not firing.

 Mike
  Hmm, thought my lectures were copyrighted.  LOL

Offline Guidematic

  • CLC# 19186
  • Posts: 879
  • Name: M. Jones
Re: Car won't start. Fuel problem?
« Reply #8 on: December 13, 2012, 08:55:35 AM »

 No harm in reiterating, eh? Seems that is all to often forgotten.

 Mike
1970 Fleetwood Brougham 68169
1985 Eldorado Coupe 6EL57
1988 Eldorado Biarritz 6EL57
1990 Brougham d'Elegance 6DW69
1994 Fleetwood Brougham 6DW69

Offline Dave Shepherd

  • Posts: 1748
Re: Car won't start. Fuel problem?
« Reply #9 on: December 13, 2012, 12:11:31 PM »
No harm in reiterating, eh? Seems that is all to often forgotten.

 Mike    Agreed. the basics seem to drift  away.

Offline 76eldo

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      CLC Member #22443
  • Name: Brian Rachlin
Re: Car won't start. Fuel problem?
« Reply #10 on: December 13, 2012, 03:40:06 PM »
Of all of the things that can come on all of a sudden, fuel pump and ignition module are the top 2.

Burned up or disconnected wiring at the starter or oil sender can create this situation too.

Might be time for to make friends with a local mechanic.  you can only get educated guesses here.  Ya gotta get your hands dirty to figure this out.

Brian
Brian Rachlin
Huntingdon Valley, Pa
CLC # 22443

Lifelong Cadillac Enthusiast
Currently own several Cadillacs
ranging from 1960 to 2007

Offline Rick Biarritz

  • Posts: 303
  • Name: R. Ould
Re: Car won't start. Fuel problem?
« Reply #11 on: December 14, 2012, 01:28:16 PM »
If I'm reading the shop manual correctly, the fuel pump is inside the gas tank?

Offline Dave Shepherd

  • Posts: 1748
Re: Car won't start. Fuel problem?
« Reply #12 on: December 14, 2012, 02:26:05 PM »
Correct, most fuel injected cars had in tank pumps, 10-13 psi is the running pressure at the injectors,  regulated in the throttle body.

Offline Rick Biarritz

  • Posts: 303
  • Name: R. Ould
Re: Car won't start. Fuel problem?
« Reply #13 on: December 15, 2012, 09:02:32 AM »
To hear the fuel pump would it be best to get under the car? Lean over the open trunk? Or should I be able to hear it just standing at the rear?

Offline 76eldo

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      CLC Member #22443
  • Name: Brian Rachlin
Re: Car won't start. Fuel problem?
« Reply #14 on: December 15, 2012, 09:22:47 AM »
The fuel pump only runs for a few seconds when you turn the key on or when cranking the engine. If the oil pressure sender is not seeing oil pressure the voltage to the fuel pump is cut.

So if you turn in the key and run to the back of the car you will not hear anything.

Take the lid off if the air cleaner. Spray a little  if starting fluid into the throttle body.
If the car tries to start then you have spark but no fuel.

That's a simple test.
Brian Rachlin
Huntingdon Valley, Pa
CLC # 22443

Lifelong Cadillac Enthusiast
Currently own several Cadillacs
ranging from 1960 to 2007

Offline TJ Hopland

  • Posts: 4157
Re: Car won't start. Fuel problem?
« Reply #15 on: December 15, 2012, 10:05:14 AM »
I dont have time to go look for my 83 book now but I am thinking there is a test terminal somewhere that you can put power to that forces the fuel pump to run. 

I presume you are not seeing fuel coming out the injectors during cranking?
StPaul/Mpls, MN USA

73 Eldo convert w/aftermarket EFI
75 Eldo rusty but trusty
80 Eldo Diesel
And other assorted stuff I keep buying for some reason

Offline Rick Biarritz

  • Posts: 303
  • Name: R. Ould
Re: Car won't start. Fuel problem?
« Reply #16 on: December 15, 2012, 10:08:59 AM »
Okay, I opened the trunk, had my wife turn the key, and I heard the pump clear as day for about 1 second. No, I am not seeing fuel from the injectors when I crank the engine.

Offline TJ Hopland

  • Posts: 4157
Re: Car won't start. Fuel problem?
« Reply #17 on: December 15, 2012, 10:15:27 AM »
There is a chunk of hose that attaches the fuel pump to the sending unit inside the tank, at this age I have seen it where that hose splits so you dont get much fuel pressure.  Usually with these if there is any pressure at all you will get at least a few drops out of the injectors.

A shot of starting fluid in the throttle body would be a quick way to see if you have spark.   If there is no spark that could also explain why there is no fuel since the distributor is what signals the computer to run the injectors. 
StPaul/Mpls, MN USA

73 Eldo convert w/aftermarket EFI
75 Eldo rusty but trusty
80 Eldo Diesel
And other assorted stuff I keep buying for some reason

Offline curly

  • Posts: 294
  • Name: T Lewis
Re: Car won't start. Fuel problem?
« Reply #18 on: December 15, 2012, 10:33:51 AM »
There is a fuel pump prime connector, light blue wire, tied in to the oil psi switch. Mitchell doesn't give a location.  If you need it, trace the wiring from the oil psi switch.  I agree with the others, it sounds like your ignition module has failed.

FYI, Gm used two different methods of controlling the fuel pump with the Oil Psi switch. One cuts the fuel pump pressure if there is no oil psi, the other acts as a back up to the fuel pump relay. If the relay fails, the oil psi switch closes the circuit after oil psi comes up. The result is slightly extended cranking before a start, but it doesn't leave you in 'Tennis Shoe mode'.  This car uses the 2nd method, which I believe is the only one GM used on EFI motors.

T Lewis

Offline TJ Hopland

  • Posts: 4157
Re: Car won't start. Fuel problem?
« Reply #19 on: December 16, 2012, 09:51:45 AM »
That would be a possible cause if it started and then quit but he says he can hear the pump running so its at least priming so there should be at least an initial burst of fuel which would at least make the engine pop a few times when he first tries to start it but it sounds like at this point there is no signs of fuel or popping.   

We will just have to wait till he checks for spark. 
StPaul/Mpls, MN USA

73 Eldo convert w/aftermarket EFI
75 Eldo rusty but trusty
80 Eldo Diesel
And other assorted stuff I keep buying for some reason

 



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