92 Devil- crank but no start puzzle

AMENCADDY · #1 (**permalink**) 07-24-08, 09:16 PM

This is my first post coz I need an EXPERT (sal?)

I am somewhat puzzled by the fact that my Deville just has no spark, after running beautifully for a couple hundred miles, so let me list some questions I have. First let me just say, I've been studying these posts for years and with the info gathered here was able to repair the fuel system on my Cad and she was running beautifully. 140K but pretty with the Gold trim, there are still some little electrical problems, like driver window stuck closed, AC doesn't. My fuel data center went blank so I can't read any codes anymore. Little things like that.

Although an elderly lady, I am very skilled at auto mechanics and electronics. I bought one of the factory manuals for the car on Ebay and it has helped beyond all else. Even so, this problem is a challenge. Distributor components, HV coil, PU coil, control module SEEM to check out according to the listed tests in the "crank but no start" section. The tank is full of gas and it squirts out at the pressure valve on the fuel rail. The cap, rotor, and plugs are brand new. All the fuses are okay.

WTH is wrong with it? Any clues because I simply can't afford to throw money at it by guessing this time.

There is one other factor I will mention that bothers me. The battery may have been overcharging, which indicates a Gen-voltage regulator barbecue. It displayed some "wet" substance on the Pos terminal (NOT the side mount) and I can't imagine that it was plain water, plus the battery now removed from the car is having a heck of a time charging to over 11.93 volts. If the case is that the battery got cooked, could this have also fried (God forbid) something relating to the ignition spark??
BTW, I live in Hawaii, and it is HOT AS HELL.

All advice is welcome and thanks in advance.

**Ranger** · #2 (**permalink**) 07-24-08, 09:59 PM

Quote:

The tank is full of gas and it squirts out at the pressure valve on the fuel rail.

Do you know what the actual fuel pressure is? 20 psi would squirt, but never start. It needs 45-50 psi.

cadillac_al · #3 (**permalink**) 07-24-08, 10:14 PM

Are there any codes?

AMENCADDY · #4 (**permalink**) 07-24-08, 11:32 PM

Quote:

Originally Posted by Ranger

Do you know what the actual fuel pressure is? 20 psi would squirt, but never start. It needs 45-50 psi.

By squirt, I meant, I barely pushed the schrader valve for a split second and fuel was present. I can't actually measure the real pressure, but I can tell you that the fuel pressure reg is brand new and I would be shocked if the pressure was too low. Although, anything is possible with this logic defying problem. I haven't totally ruled out fuel but remember there is NO SPARK either.

AMENCADDY · #5 (**permalink**) 07-24-08, 11:36 PM

Quote:

Originally Posted by cadillac_al

Are there any codes?

I'm sure there are but The fuel data center died and doesn't display.

. Is it possible to read the codes some other way, like the ADL port with just a digital VOM? I don't have a fancy code reader.

**Ranger** · #6 (**permalink**) 07-25-08, 12:12 AM

Quote:

I haven't totally ruled out fuel but remember there is NO SPARK either.

Then I'd assume fuel pressure is OK and concentrate on ignition.

Quote:

I don't have a fancy code reader.

Harbor Freight has some non fancy code readers for about $40.

AMENCADDY · #7 (**permalink**) 07-25-08, 01:28 AM

Quote:

Originally Posted by Ranger

Then I'd assume fuel pressure is OK and concentrate on ignition.
Harbor Freight has some non fancy code readers for about $40.

oK, Ign, it is. I may have to tear into the dash (again!) and try to Tshoot the fuel data center. It's just so weird that on my last drive, about 15 miles, she worked so perfect that I gave her a bath. Then the next time, a few days later, it cranked super fast like a brand new 12.5 volt bat, but no start and no spark. I even visually checked the coil. It's old but nothing bad observed. the wiring in the distributor has the standard cracked-falling-apart connectors to the control module but the wiring still had proper continuity and voltage readings according to the tests.
Can a bad voltage regulator make the PCM override the ignition sys ability to fire the coil?

cadillac_al · #8 (**permalink**) 07-25-08, 08:23 AM

Somehow you are going to have to let the diagnostic system do its job. If it were me, I would look for another fuel data display on ebay or invest in a cheap code reader. Sometimes I see complete distributers on Ebay and I'm tempted to buy one for a spare. Good luck

madmike69 · #9 (**permalink**) 07-25-08, 09:42 AM

Hi,

Car cranks but does not start? (both??--->)Displays off?
My 88 DeVille just had a loosen Connector near the negative Battery Pole
in the main ground Cable for the ECM and BCM...

...We searched like sick Coyotes and removed the whole under Dashboard wiring Harnesses till we found out.

CHECK THIS FIRST !!

Good Luck !!

donwon · #10 (**permalink**) 07-25-08, 12:30 PM

I bought an Igination Module from Advance Auto for under $20. It was made in china.
I then replaced it with a GM Ignition Module that cost much more and it was made in Hong Cong.
I still have the cheep one as a spare.
Some auto parts houses have a way to test these modules, and will do it for free.
There is a pigtail between the ashtray and the firewall for an OBD1 to hook into.
Guess I havn't told you anything you didn't already know.

**Ranger** · #11 (**permalink**) 07-25-08, 05:31 PM

Quote:

Originally Posted by AMENCADDY

oK, Ign, it is. I may have to tear into the dash (again!) and try to Tshoot the fuel data center. It's just so weird that on my last drive, about 15 miles, she worked so perfect that I gave her a bath. Then the next time, a few days later, it cranked super fast like a brand new 12.5 volt bat, but no start and no spark. I even visually checked the coil. It's old but nothing bad observed. the wiring in the distributor has the standard cracked-falling-apart connectors to the control module but the wiring still had proper continuity and voltage readings according to the tests.
Can a bad voltage regulator make the PCM override the ignition sys ability to fire the coil?

I'm not really sure, but I do recall people having similar problems and after much trouble shooting and part swapping they finally replaced the distributor, solving the problem. just a thought, but I'd check all the grounds first, as suggested.

AMENCADDY · #12 (**permalink**) 07-25-08, 08:41 PM

Quote:

Originally Posted by madmike69

Hi,
Car cranks but does not start? (both??--->)Displays off?
My 88 DeVille just had a loosen Connector near the negative Battery Pole
in the main ground Cable for the ECM and BCM...
...We searched like sick Coyotes and removed the whole under Dashboard wiring Harnesses till we found out.
CHECK THIS FIRST !!
Good Luck !!

Didn't know it grounds the PCM but believe it or not THIS suggestion is like the missing puzzle piece, cos I'm sure it got wet when I bathed the car generously with water. Right after this bath the problem occurred and furthermore I had been suspicious of that little post already. The car had an intermittent clunk at start and by just a finger budge on that post and the NEG battery cable she would always start up real clean for a few more times and I have been meaning to completely disect that (very dirty) little post, clean, file and make sure all those wires attached to it get pure electron flow. I BET YOU ARE RIGHT, SIR. Thanks so much and I'll let all you wonderful folks trying to help me, know if this is it, as soon as I get to it tomorrow or next day. Thanks a million for the tip.

AMENCADDY · #13 (**permalink**) 08-03-08, 08:15 PM

Today, I checked the ground post as suggested but car still has the "crank but no start" problem, so back to the drawing board I go. But according the the GND Distribution charts, the main computer G's are spliced to that iddy, biddy black and white wire right at the battery. There are 2 more G's behind the RH shroud and LH shroud to check, but one question if anyone could tell me, is "shroud" a panel on the RH or LH side of the dash, like hidden by where the glove compartment is (RH) and LH one is where the E-brake is? or is it inside the engine compartment? Hard to tell from the diagram.

AMENCADDY · #14 (**permalink**) 02-14-09, 10:45 AM

HA HA HA! problem solved! Sorry to take so long to finally get the repair done, but I'm getting old and slow. It turned out to be the obvious thing -ignition control module! Boy, do I feel dumb. Ain't it funny how things are not always what they seem, and there was no connection to my washing the car or the open ground. The damn thing just died!

I guess 141K mileage can do that to a few vital parts, even on the mighty Caddy.

Happy Valentines Day and thanks for all your help.