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1993 Fleetwood
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Discussion Starter #1
hey all
i have a 95 deville with a 4.9 and one day over the winter it just decided not to start, i had just come home from work and it was running great then i changed to go out and it jus kept cranking, and cranking but wouldn't start.
i had it towed to my mechanic who said it wasn't getting spark so he replaced the distributor and that was no help so he checked for codes and it says it said ecm internal fault or sumthin like that and replaced the ecm and it still won't start, the battery is new and it has a full tank of gas, but it'll just crank all day to the point that the car will shake but nvr kicks over:confused:he got fed up with it and i took the car back but what can be done now? is there a module i can get to create spark or something that can b bypassed to make it go again?
sorry i wrote a book. any help would be greatly appreciated thanx
 

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'85 Fleetwood FWD
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728 Posts
When you said "it shakes but wont start" you seem to imply that it wants to start. Did your mechanic check the fuel pressure? He would have to hook up a gauge to the incoming fuel line ( Cadillacs have a line tee with a cap on it) and check pressure while hot-wiring the fuel pump with the single wire connector near the battery, that's provided for that purpose. It could be the fuel pump, the fuel pump relay or.... A good pressure on the gauge would at least help eliminate the fuel as a problem. Older cars like mine ('85) require a pressure of 9 to 15 PSI. Don't know what yours would require. Also, the fuel pump wiring goes through an oil pressure switch, meaning it wont run (except for a few seconds when ignition is turned on) without oil pressure.

Hope this helps......
 

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1993 Fleetwood
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Discussion Starter #3
i'm not sure if he checked the fuel pressure i just assumed he would have gotten the simpler things out of the way first before telling me the problem was no spark, is this something i would be able to check in the driveway?
 

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1992 Sedan Deville, 1984 Lincoln Town Car
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Your FP should be 45-50 psi. but to just crank if there was fuel present, you'd think it would at least start and then choke out and stall if the pressure was low. This you can check at the schrader valve with just a little quick tap to the valve and if fuel squirts out it's probly enough to at least start the car. Do you think the "mechanic" bothered to check the fuses for your fuel injectors? or the fuel pump.! (duh!)
 

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1993 Fleetwood
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Discussion Starter #5
yea that would seem the obvious things to try first and i assume he did but not sure, and if i hit the gas while trying to start after a few seconds i start to smell gas so i also assume that its working as well but i guess it couldn't hurt to check
 

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1992 Sedan Deville, 1984 Lincoln Town Car
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If you are smelling gas, and it still isn't starting, lemme just ask a stupid question. are you positively SURE, that you are getting spark? I know the the Ign system was replaceed with all new stuff supposedly, but might want to double check. NEW means "never ever worked", FYI.:rolleyes:
 

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1993 Fleetwood
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Discussion Starter #7
hahaha i'm pretty sure i'm not getting spark as i was told by the mechanic that that was indeed the problem i don't mean to laugh but i'm sure u can understand my fustration and the replacements are junk yard parts so yes it is possible that they are also defective just not sure how to test for such or to know if i should just buy new or if there is another way around it?
 

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1992 Sedan Deville, 1984 Lincoln Town Car
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OMG<OK :banghead::histeric: that explains everyting! . Please tell me it is a NON N* engine. If it is, the way to T-shoot the NO sparky is much easier than the N*. Mainly because you'll have a real distributor like God intended. Wait, you already said your "mechanic" replaced that so. Lemme ask another stupid question. Does he know how to check it for spark or did he ASS-ume that all the junkyard parts worked.? Are you even still on speaking terms with this dude? You can DIY perty ez if you want some help.
 

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70 Deville 77 Fleet 78 Seville 92 Deville 03 Deville
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Since it was towed to a mechanic we have to assume that he did all the normal troubleshooting. Stuff like pulling a couple plugs to see how wet they are and check for spark and verify 12 volts at the distributer. Since it happened all of a sudden it probably "was" the ignition module. The junkyard distributer probably needs one too. I hope it was reinstalled correctly but it should be if the guy is in business.

If the plugs get real wet they may not fire. That usually doesn't happen on modern fuel injection buy you mentioned that you smelled gas and you were stepping on the accelerator. My old 76 Seville would drown the plugs if I did that but I don't think the 4.9 will inject that much, but I'm not positive on that If your mechanic got tired of it and you brought it home then you may have to find another mechanic. Good luck.
 

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1992 Sedan Deville, 1984 Lincoln Town Car
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Here is how I checked for spark alone on my Cad.
I happened to have the old plugs & wires, so I took the longest one I had (u could just use one of the currently installed ones for the same test) and one of the plugs that looked like it would fire. then I unplugged one of the wires closest to the Driver side top of the Dist-cap, plugged my "testing" one in there and set it through the open hood at the bottom so I could spot it while I cranked the engine. Absolutely no spark! Shocker because the car had been running perfect when I parked it. Double checked this time holding the plug wire in the middle while standing outside the Driver side; then I could reach in and crank the Ign. Still not even a hint of spark. That's how I determined that no spark was present. Fuel was present which I determined by just tapping the Schrader valve on the end of the fuel rail with a little screwdriver and tissue (real quick so fuel wouldn't spray me) It had fuel, just no spark. Months went by because I couldn't afford to make a mistake with purchasing either the coil or the control module, both of which tested good according to the FSM ON-vehicle procedures. Finally, I got up the courage (and extra budget arrived $$$) to remove the control module, took it down to NAPA where the guy tested it 3-times. Tested bad, so I gulped and forked over $30 for their "cheaper" version of this $70 part. and Voila! she now purrs like a kitten. Sorry for the novel, but it just poured out. Now for my morning cup of coffee to pour out. Later, guys!
 

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1993 Fleetwood
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Discussion Starter #11
i bought a new ignition control module yesterday and as i was removing the old one the harness with the 3 yellow wires broke so i was trying to be as careful as possible putting the new one back in but the wires pushed out of the harness and i failed to notice which order they should b in in the harness do any of you know how they should be?
 

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1992 Sedan Deville, 1984 Lincoln Town Car
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I can help but I need to know what color they are really. If they're all 3 yellow, it's kinda hard to tell which is which :histeric:
 

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1993 Fleetwood
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Discussion Starter #13
oh yea :duh: that does make sense lol
they're is yellow, yellow w/ black and yellow w/ brown
 

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1992 Sedan Deville, 1984 Lincoln Town Car
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Yep! those are delicate little buggers. Here is the chart from my 92. but there are no yellow wires.
Maybe dirt is covering the true wire color. but you can do it PIN TO PIN visual I guess.
Just make yourself a little notepad chart with the diagram in case you get a brain cramp memory loss.
It's the same module, I checked on Rock Auto. GM engineering wisdom may have changed the color code just to confuse the DIYers.

Distributor 6-hole 5 wire connector = to Module
A - WHITE = E (middle)
B - PURPLE / WHITE = R
C - TAN / BLACK = B (end outside)
D - BLACK / RED = GND (hold down screw)
E - BRN / WHITE = Hall effect (Cam Sensor)

Module side with 5 pins = to 6 pin Connector
If you look at your old module you will see the pins are as follows: just do a match-up to above pin reference on the 6-way connector
B - TAN / BLK = C
R - PURPLE / WHITE = B
E - WHITE = A
N - PICK-UP COIL WHITE = 2 pin connector
P - PICK-UP COIL GREEN (end inside) = 2 pin connector

Try to have fun. NOTE: pin E on the module is quite different than E on the connector. (more GM wisdom)
 

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1993 Fleetwood
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Discussion Starter #15
thank you for that amencaddy turns out after closer inspection the wires are just dis-colored and not actually yellow and my attempt at remembering were they came from worked :)
but now i'm stumped again because now i have a new ignition module (correctly installed) and just today picked up a new ecm from a local dealer and still no start :-/ what else could it be?
 

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1992 Sedan Deville, 1984 Lincoln Town Car
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Is it now getting spark with the new module?
If not, are you sure you hooked up the wires correctly (use my previous post with the layout)? Is there 12V at the B connector going into the Dist. Cap. The other possibility is the Coil is bad or it could be the Pick0up coil in the Distributor or the Hall effect switch (CAM sensor).

Check OBD for codes.
 

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1993 Fleetwood
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Discussion Starter #17
ok so i finally got a day off without rain and tried again to test things.
thanks again amencaddy for the diagram then i went to alldata and got the test sheet for the po12 code which is what my mechanic said was wrong now and according to the flow chart what is left is repairing an open or short to ground in ckt 430 between c108 (distributer connector) bin b and pcm terminal 1d8 but when i did a continuity test from pin to pin there is no resistance so it apparently isn't open could it still be shorted to ground somehow? :hmm::banghead:
 
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