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Cadillac Deville crank but no start


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I don't know.......could be something.....could be nothing. Current or history code? 

Aftermarket stereo?

Hard to tell with sporadic 36-48 hour postings.. 

I guess best to wait and see on the HEI tester.

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Sorry it's been pretty cold in windy here in northern iowa and garage is unheated.  Need to get a heater for it.. I will try and get that info for you tomorrow.  Do I need to check for spark on all coils?  I'm just thinking about not having to do the back ones.  Is doing the front ones good enough?

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I NEED to get my GMSi running again

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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Ok did fuel pressure test.  Relieved pressure then did my test.  1st key on PSI was around 16 to 17.  That was low.  2nd key on was 32 PSI.  3rd key on was 37 PSI.  Tried starting on 4th time.  No start but PSI was 40.  Relieved fuel pressure to 0.  Key on 5th time and PSI at 38.  This normal?  Disconnected fuel lines to get sample to check for water.  Put fuel rails in a jug and only was able to pull out like 4 to 6 ounces.  I turned the key on and off 3 to 4 times but no more came out even though pump ran each time.  Is this normal?  I expected to draw out a lot more fuel for my sample.  Kind of surprised me.   Wasnt able to check for spark yet but hopefully tomorrow.

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I'm not a mechanic, so just as a grain of salt; I believe running pressure is around 50 psi but I don't know what minimal is.  Partially blocked fuel filter can reduce pressure (assuming the pump is fine).

Edited by cdgrinci

Chuck

'19 CT6, '04 Bravada........but still lusting for that '69 Z-28

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Assuming your gage is good that key on pressure  is terrible!!!

Retest fuel pressure

Do it with key on

Do it cranking

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 fuel comes from the gage, does you gage have a button on it that when you push it,.it releases pressure and fuel into a separate hose?  

This is sounding like a fuel pump or clogged fuel filter

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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Fuel gage is brand new and yes it has a bleeder hose.  Seemed to be working fine.  I was thinking clogged fuel filter also.  Btw no after market radio or remote start on car Logan. (Earlier post)  I'll get a fuel filter and install that soon.  Anybody help me with spark?  Do I need to test every coil? Thanks for help guys!

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Focus on fuel first, I think you may have found your problem.  If a filter doesnt solve it its the pump.  After, 2001 or so, there is an access panel in the trunk to access the pump. You say, its running so electrically it sounds good.

But, at least test one spark plug from each bank just to knock it off your list.  But that pressure is low

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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Pressure is way low. You need to worry about getting the pressure up before worrying about the codes. 

Did find a Youtube video. ....not my video...not sure how they mangled up the panel some..

I would quickly check the fuel pump wiring connector for burnt or blued wire connections before pulling the pump. Common problem....car may already have a new pump for this issue. 

 

burnt.jpg

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even if pump is new that does not mean that the new plug was installed. 

Both of mine had the problem with the burnt plugs.

Have done many other GMs with the same problem

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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Ok guys, changed fuel filter.  Didn't fix my no start but my fuel pressure hovers between 36 and 39 PSI with key in on position.  Inspected pump and it looked good.  Connectors looked fine no signs of burning or over heating.  Disconnected and reconnected.  PSI remained at 39 PSI.  What is PSI supposed to be?  Over 40 PSI?  Car sounds a lot stronger now but still no start.  Look for spark now?

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I still think pressure is low.  Found this video (maybe it will help); it also alludes to about 50 psi:  

 

Chuck

'19 CT6, '04 Bravada........but still lusting for that '69 Z-28

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So you think it's a weak fuel pump or bad fuel pressure regulator?  I could not tell if it was an aftermarket fuel pump.  I guess if spark checks out then I will look at replacing fuel pump.  I hope to test for spark today.

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definitely confirm spark first, you replaced so much, you need to confirm that. 

when you go to start the car the next time, hold your foot to the floor, if I recall, that will induce flood mode, and turn the injectors off, you may have wet plugs.  crank it a few times with your foot to the floor.  then lift off. 

check your regulator by pulling the vacuum hose off and seeing if you observe fuel in the hose or spitting from the regulator, any fuel at all on the vacuum side, replace the regulator

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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By the way, the regulator will usually only spit fuel when you rev the engine with the vacuum hose off, put a white index card in front of the nipple as you rev the engine.  

But you may see evidence of fuel when you pull the hose off.

Check for codes again 

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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Obviously you can't.   Watch it while its being cranked thoigh,   

Something tells.me that your engine should at least start at the pressures you are seeing, it won't run well, but it should start.   I still find it odd you could not get a jar of fuel from the system, key on, gage attached, pressure showing on gage, push button on gage and half fill a clear container.  Water and fuel separate.  Please do this.  You MUST begin eliminating potential problems.

Check spark and please, disconnect the battery, try to start and then check for codes.  

Keep the battery charged, don't crank longer than 10 seconds.  

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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Ok I checked for spark and have 0 spark.  At least on two different coils on the front.  Where do I look now?  Gas seems fine.   No separation that I can tell.  There was only a quarter of a tank that I drained most of when I changed fuel filter.  Added fresh unleaded gas only.  Fuel pressure regulator does not leak even while cranking.

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Can you explain exactly how you tested for spark? I guess we want to verify your procedure... Did you get a HEI tester? 

I would likely check every one....should be pretty easy to do. 

I would also get some of the gas from the fuel rail end (from relief hose) ......pour a little bit on a sidewalk.....and see if you can get it to light and burn. 

If bad gas....there can be a bunch between the tank and the fuel rail. 

Can be sour....sugar....diesel etc mixed in.

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Very true about the amount in rails.  I'll pull some from the rails and try to light it.  I bought HEI tester and unscrewed coil plug, inserted hei tester in the coil plug and had someone try to start car.  Coil was still connected to car.  Tried 2 of the front coils.  Is this correct method?  Could my problem be an ignition control module? Just seems like something is not communicating with coil packs.

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Did you have the HEI tester clipped to metal ground? You can use a pigtail if no ground is within reach. 

It wont spark if it is not clipped to ground. 

Another youtube.....not me....

 

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