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Intermittent Starting Problem; Dealer Stumped


usalj

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My 99 Deville has had intermittent starting problems for months. Usually, but not always, the problem occurs after driving for a while, then shutting it down, then trying to restart it later. Cranking occurs (until the battery drains), but the engine does not catch. After a while (15 minutes to a few hours) , it sometimes starts up.

A couple of times, the car also stalled while driving, but this has not happened since the alternator & compressor were replaced a few weeks ago.

Each time I bring it in to the Cadillac Dealer (even after a tow was needed last Monday) they say the car starts right up, even after short drives. They say there are no error codes & everything checks out (battery, starter, fuel pump, et cetera).

Any advice?

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I would check the battery cables, grounds and the fuel pressure regulator and fuel pump.

Intermittant problems are hard to find. That the car has not been setting codes complicates it. The NEXT time this happens check for codes IMMEDIATELY and see if you are setting a code that is going away. The fuel pressure regulator will not set a code, nor will the fuel pump. You might have a fuel pressure gage on hand also, the next time it happens hook it up and see what pressure you have with the key on. Mike

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Has to be either a fuel or ignition related problem and ignition is the most likely because of the 'no error codes'.

All ignition events on your engine are based on data from the crankshaft position sensors located on the left side (front) accessable from the bottom. I would exercise the connectors a few times to wipe the contacts clean. Do the same to the four low voltage connectors on the ignition control module.

If you resort to blindly throwing parts at it, the crankshaft position sensors would be the most likely suspects.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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Update: The Caddy Dealer said on Friday that he still could find nothing wrong, but showed me how to check for codes if it stalled again. It stalled again this morning (& eventually started up an hour later, with a boost) & I was able to get an error code at the time: PCM P0231 (Fuel Pump Secondary Circuit Low). I'll tell the Dealer tomorrow & see what he says. Any further advice?

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As BodybyFisher said, cables and grounds. If it only started after a boost then battery or alternator are very likely the problems. Did they check the alternator UNDER LOAD? Very big difference than just checking output no load.

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Yes.

That is right.

Those worthless scums at western auto (no offense to those scums) kept cheating me on alternators for my ex wifes POS (offense to mazda) import because they were always fine on their stupid machine

Finally,

I had one made and custom fitted it to the little car.

That beat anything any ASE or other idiot tried.

Never busted a belt again - never had another dead battery.

MerryChristmas

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Be a Capitalist or work for one.

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Work for a Capitalist or be one.

MerryChristmas

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Do ODBII Caddys have the ability to take a PCM "snapshot" as the OBDI Caddys do?

I don't know if it would be helpful in this case, but I've always been intrigued by that troubleshooting aid. I can see where it might really help "nail" an intermittent.

Regards,

Warren

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There is no means of avoiding the final collapse of a boom brought about by credit expansion. The alternative is only whether the crisis should come sooner as the result of a voluntary abandonment of further credit expansion, or later as a final and total catastrophe of the currency system involved. - Ludwig von Mises

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As BodybyFisher said, cables and grounds. If it only started after a boost then battery or alternator are very likely the problems. Did they check the alternator UNDER LOAD? Very big difference than just checking output no load.

They replaced the alternator a few weeks ago! Also, the first 2 boosts didn't help. By the time I tried the 3rd one, the battery had been drained, so a boost was necessary just to crank the motor. The engine finally kicked in.

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I agree that ignition could be the cause, but don't give up on the potential of the fuel system causing trouble. Immediately after the next "no start". Check to see if the fuel pump is coming on. When you first turn the ignition on, the fuel pump should run for 2 seconds to presurize the system. The pump make a quite "wirrring" sound. You could also check to see if there is pressure in the fuel rail. There is a valve on the rail that looks like a tire valve. The only problem with this, if that if there is pressure, it will shoot gas at you.

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Sounds like you might have a bad fuel pump relay or your fuel pump is beginning to go.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Check to see if the fuel pump is coming on. When you first turn the ignition on, the fuel pump should run for 2 seconds to presurize the system. The pump make a quite "wirrring" sound.

I've heard of this many times and have listened intently for that sound often over the years; I've never experienced it! I haven't had a hearing test in years, but I'm in the audio business and think I'd have noticed a deficiency in the hearing area by now.

My point is: I don't think you can rely on that "test." At least not where my car is concerned. :P

Some here, in the case of fuel pressure concerns, have suggested connecting a pressure gauge (with a long hose) and duct-taping the gauge to your windshield such that you might observe the pressure during the failure period. Ah, Duct tape . . . . . ain't it grand? (Don't get your gauge stolen).

A thought: power to the fuel pump is supplied though two paths. First, the fuelpump relay; secondly, in the event the fuel pump relay fails, the oil pressure switch will provide power to the fuel pump (after a certain oil pressure is reached) to get your N* running. This typically results in a "hard starting" complaint, but your car will still run if your fuel pump relay is bad. Both circuits would have to fail to account for a "crank-no-start" situation. Unlikely.

Regards,

Warren

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There is no means of avoiding the final collapse of a boom brought about by credit expansion. The alternative is only whether the crisis should come sooner as the result of a voluntary abandonment of further credit expansion, or later as a final and total catastrophe of the currency system involved. - Ludwig von Mises

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The additional info changes what I said about the alternator/battery. I thought it was dead when you first tried to start it.

Fuel pump/wiring harness in gas tank/fuel pump relay and circuit can all be the problem. If there is a Harbor Freight near you get their fuel pressure gauge. Less than $15 regular price, less than $10 on sale. Hook it up and leave it attached. Tie it up safely in the engine compartment. When it does not start check the pressure. It should be about 45psi. It should show that even if you are not cranking the engine. As little a drop as to 40 can cause starting problems.

If I'm off on the pressure someone chime in.

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My 99 Deville has had intermittent starting problems for months. Usually, but not always, the problem occurs after driving for a while, then shutting it down, then trying to restart it later. Cranking occurs (until the battery drains), but the engine does not catch. After a while (15 minutes to a few hours) , it sometimes starts up.

A couple of times, the car also stalled while driving, but this has not happened since the alternator & compressor were replaced a few weeks ago.

Each time I bring it in to the Cadillac Dealer (even after a tow was needed last Monday) they say the car starts right up, even after short drives. They say there are no error codes & everything checks out (battery, starter, fuel pump, et cetera).

Any advice?

Everything everone has said here is good advice. I do remember something else that may be interesting to you and your dealer. In some Cadillacs in our model year range (I have a 1997 ETC), the connector to the fuel pump in the fuel tank could have an intermittent connection. This happened to me, and I understood at the time from the dealer and others that it wasn't uncommon. Symptoms were intermittent, and included stalling -- sometimes while simply driving at, say, 50 mph -- and occasional hard starting. It gets gradually worse. This, and your OBD II code suggest looking very hard at the fuel pump and its immediate wiring.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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  • 2 weeks later...

Keep us informed on this if you would, for our experience, Thanks, Mike

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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So here I was hoping that replacing the fuel pump last week would finally do the trick. But I had a stall again today with the same code: PCM P0231 (Fuel Pump Secondary Circuit Low)! It started properly about 15 minutes later. So back to square 1 & I'll call the dealer again tomorrow. I actually stopped at another mechanic today & he confirmed that intermittent problems like this are almost impossible to diagnose, unless the mechanic can work on it while the problem exists. He also suggested that the ground near the fuel pump may not be secure. I even tried starting it up while I was at the mechanic about 10 times in a row & it started up each time.

Any suggestions?

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If the relay has not been replaced I would replace it, and I know the oil pump has a back up switch, but its cheap enough. I would as the mechanic said, clean the ground and connectors

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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The 1997 factory manual says that P0231 is set when there are no volts on the fuel pump line, as sensed at the output of the fuel pump relay, when the engine starts to crank or is running. This must hold for 1.3 seconds to set the code. If the condition clears the next time you start the vehicle, the code will clear but will be reported as a history code. Thay say that if there is no "driveabilty complaint" to check the connection between the fuel pump relay and the PCM (the wire used to sense the problem) but if there is a "driveabilty complaint" as in your case, to check the relay and its connections, and it specifically mentions the relay ground connection.

They have a very good diagnostic and test process in the factory shop manual pages 6-420 and 6-421 for this problem. If someone goes through that, they will find the problem.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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Update: Dealer changed the battery (1 dead fuel cell); relay; and computer. They checked the ground & wiring all through & said it looked fine. They had already replaced the alternator, compressor & fuel pump. I may have a completely rebuilt car before this is over! We'll see what happens next.

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It was probably the battery with the deal cell... Keep us up to date with this. Glad you found it, Mike

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Back to square 1: Stalled today while driving, with the same error code, P0231. It cranked but would not start for about 10 minutes. In the interim I had switched the new relay again with another one. The relays felt very hot during the switch. Stalled again 5 minutes later & restarted 5 minutes after that. Dropped it off again at the dealer, where it started right up multiple times.

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That is really frustrating! You have replaced everything that could cause it.. Very hot relay, the fuel pump relay? If the fuel pump is new, I wonder if its a bad connection causing high resistance?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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P0231 - Fuel Pump Feedback Circuit Low Voltage

This code is set when the engine is cranking but the fuel pump relay isn't turning on the fuel pump, as far as the PCM can see. Thus either there is no power coming out of the fuel pump relay or the sensing line to the PCM is bad. The no-start complaint tells us that it isn't the sensing line.

The 1997 FSM pages 6-419 through 6-422 have the recommended process to diangose and fix problems that cause P0231 to be set. One of the first things that they say si that the PCM may record operating conditions at the time of the faiulre in the Failure Records.

In the instructions for diangosis and repair for P0231, if the problem is not reproducable then refer to Diagnostic Aids, which I can't locate in the FSM. I would continue with the procedure. There is a mention of Failure Records in the PCM and the next steps call for hooking up the diagnostic computer and monitoring the fuel pump feedback voltage. It may be that the dealer hasn't gotten serious enough to pull out the big guns, and this problem requires that they do just that.

There is a "Clear Flood Mode" on page 6-815. If you push the accelerator to WOT, the PCM will completely turn off the injectors and will maintain this as long as it sees a WOT condition with engine speed below 1000 RPM. Are you trying to start it without touching the accelerator?

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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  • 2 weeks later...

So here's the latest update: After 2 weeks at the Dealer, who was "consulting with GM," the mechanic unhooked/removed the fuse/relay panel & saw a "red wire that sparked," an apparent indicator that it was loose. They replaced the wire, tightened everything & now I have it back again. I will see what happens.

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