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Hi,

I got a bit surprised today, went outside and remoteopened the door and sat into the car, that have been standing outside for approx 6days without beeing driven.

Click the startbutton and it crank, crank and crank. After approx 7sec I switch off, wait a while and try again same result. No attempt to ignite, engine symbol light during cranking (I dont know if this is normal or not).

No information texts or so, all in all its looks and sounds pretty normal expect it wont start.

I have replaced batteries in both transmitters, it recognise the Driver 1 and Driver 2. And it wont accept a the key if I put into the "pocket". So I dont think that's the problem.

Once I think I heard a single ignition, but it might have been my imagination also.

Any ideas what might have happened?

/Oscar

STS 2005 V8 (1SF)

Sedan DeVille 1995 4.9L

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Is the battery strong?

Are the battery cables well connected?

Is there gas in the car?

Could the gas have water in it that has not separated? (try new gas)

Can you hear the fuel pump come on before you try to start the car?

Is the engine flooding (do you smell gas?)

The engine needs spark, fuel, starter power, and oxygen to start. So when it does not start, begin to check each of those items.

Bruce

2016 Cadillac ATS-V gray/black

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Is the battery strong?

Are the battery cables well connected?

Is there gas in the car?

Could the gas have water in it that has not separated? (try new gas)

Can you hear the fuel pump come on before you try to start the car?

Is the engine flooding (do you smell gas?)

The engine needs spark, fuel, starter power, and oxygen to start. So when it does not start, begin to check each of those items.

Battery is strong and it crank at quite high speed.

3/4 of gas, refuelled recently (filled from approx 1/4 two weeks ago).

Dont hear any fuelpump, but not sure if I have heard it before either, its a silent car. Keyless go so I enter start directly and I guess thats when it turn on the fuelpump also.

Very windy outside, but I cant smell gas.

I have a slight sense of "lack of fuel", I will just wait until it stops to rain and go for some testing, inspect fuel relay and fuses. Many of them seems to be under the rearseat.

STS 2005 V8 (1SF)

Sedan DeVille 1995 4.9L

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Have someone turn the key on while you have your ear at the filler nozzle and see if you hear the pump kick on when the key is turned on or, hook up a fuel pressure gage

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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Busy days but I did some more research today. I took off the plastic shield over the engine and found the fuelrails, then I also found something on the throttlebody that I recognise as a injector (cold start?). And on the hose to the trottlebodyinjector I found a connector from which I tried to get some fuel and I didnt get anything at all. At least Bosch systems keep their system pressure for some while.

Continued to remove rear seat and tested the fuelpump relay and checked the fuse, also ok.

Does anyone know it this relay ground the pump (sometimes this is the situation when a masterrelay feed +12V) or connect it to +. Perhaps its possible to remote feed the pump.

It have tried to ignite, but its very rare (probaly intake vaccum pull fuel from injectors).

And I added 1.3gallons of fuel ... well car is outside, I'm not sure if fuelcap is locked and I have heard about petrol theifs - not where I live, but to remove all eventualities.

STS 2005 V8 (1SF)

Sedan DeVille 1995 4.9L

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Update: Start but wont stop

I think I have come a bit closer now. During searching, and testing I unfortunately pulled out a relay while ignition where ON I caused engine failure lamp to come on. I decided to charge the battery inside my garage over night.

I removed the battery and charged it fully, when I connected it I heard the fuel pump running for the 2sec it shall run, went inside the car and noticed that Instruments where on and well - here we go, pressed the button and the engine fired up directly.

I let it run for a few minutes, then I pressed OFF and most of the car shutdown, engine where running. I opened hood and engine where running I went 20yards away with the transmitter in my pocket, I locked and put on alarm - engine where running. At last I decided to pull the fuelpump fuse.

Perhaps its two circuits, one that pull starter solenoid and another that informes EFI about power-up. And now nothing the command power-down never enter the EFI box. I'm not so familiar with CAN busses.

Anyhow, this point the failtracing in another direction.

/Oscar

STS 2005 V8 (1SF)

Sedan DeVille 1995 4.9L

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  • 2 weeks later...

Solved: Works now

The start without ability to stop seems to be a faulty powertrain relay, probably damaged during failtracing.

Anyhow, after this I where sure about that the car worked and it where just a matter of transponder recoginition. So I put the car in my garage and charged fully, tried again and again, with different keys. When it finally decided to start I had driverdoor open and then attached batterycables, put the second key in the "pocket" and then made a try to start and it seems that the computer recognized the transponder as it should.

Both transponders works now, so probably something happened when I changed battery in my transponders. Next time I will change battery in one transponder and then try that it works before I change in the next one.

It have worked perfectly for a week now.

STS 2005 V8 (1SF)

Sedan DeVille 1995 4.9L

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  • 4 years later...

Hi,

I continue the tread since last time the problem dissapeared without a 100% evidence for what fault it was.
Now it happened again.
The situation is that I drove a 200miles trip and parked the car a week and planned to go back but when pushing the start button it just crank - not a sign for ignition. After doing some research I found that when I jumper the relay for fuel-pump the car start nicely and seems to work (just drove it back and forth a bit). Relay is ok - relay control is not.
Spending a few hours with Google didn't give much. So it boils down to what is controlling the fuel pump relay (wiring diagram?). It seems like the controller of the relay is intended to supply +12V to one of the terminals since I could measure a low resistance to ground on the other. Hooked up a DVM and the max reading during all the start sequence is 0V.
Have removed battery during night, charged it and have tested both FOB:s since I had both of them with me. A quarter of fuel left.
Unfortunately I don't have access to any code reader…. and Check engine is illuminating continuous. It did happen during the trip, thought it where fuel cap (again). Had a short stop (turned engine off for a minute) after 20-30sec lamp came on. Opened fuel cap when I arrived and no vaccum. Probably not related.
Any clever idéas is highly appreciated.
Thanks in advance

STS 2005 V8 (1SF)

Sedan DeVille 1995 4.9L

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If you jump the contacts on the fuel pump relay and the car starts, I would think the fuel pump relay is bad.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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If you jump the contacts on the fuel pump relay and the car starts, I would think the fuel pump relay is bad.

Thanks Kevin,

Yes but I swapped it to another relay (several of them are identical), and I measured it by applying 12V to the coil and it's ok. But I don't get any 12V to the coil that should close the relay. Just had a bit longer test ride and everything seems normal except --- it wont pull the relay.

STS 2005 V8 (1SF)

Sedan DeVille 1995 4.9L

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Maybe the socket is not making a good contact with the relay and the connection is intermittent? When you jump the contacts on the socket, it's possible you're getting a better fit.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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  • 2 weeks later...

Update : Jumpered fuel-relay with switch and drove back home after new-year, no problem except check-engine where constantly on...
Used the car a few times afterwards and suddenly after approx. 400miles check engine went off. Plugged in fuel-relay and it just started. Strange, something lock out the fuel delivery.

Have ordered an OBDII reader so I can check if there are any useful codes. Otherwise I will go to a caddy service and ask them to dig deeper into the systems with a Tech2.

I have read some commercials about Northstar and they stated that if fuel relay is not working, the oil pressure sensor will energize the fuel-pump but maybe it where earlier generations.

STS 2005 V8 (1SF)

Sedan DeVille 1995 4.9L

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