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1990 Deville Died


sixtires

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:( When it rains it pours. I took off work today to replace the front wheel bearing on my 1990 Cadillac Deville. I drove the car earlier today and it was fine. While driving on the highway, the check engine light came on, but the car was running fine. I drove it home and parked it in the garage. Now, it will not start.

I'll tell you what I ran through. I checked all the fuses. There's 10 gallons of gas in the tank. When I turn the key, I can hear the fuel pump come on. If I crack the Schrader valve on the fuel rail while cranking the car, I get a nice strong stream of fuel, so I don't believe it's fuel pump related. If I pour a little gas down the throttle plates, the car will sputter to life, then die. So, it's as if it's not getting fuel, or the injectors are not working. I've checked all the fuses, connectors, etc. When I run through the diagnostics, I get an F32 error (map sensor?).

Any ideas as to what to check next would be appreciated. It really seems as if it's the injectors, as the car will fire if I pour gas down it's throat.

Marko

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When I run through the diagnostics, I get an F32 error (map sensor?).

F32 is the code for lack of PCM-BCM communication. That is more ominous....it may mean that the PCM is dead and that the body computer cannot communicate with it because if this. F32 is not the MAP sensor code. That would be an E32 for the MAP sensor open.

I did check all the fuses, also the ones on the passenger side of the car under the dash. They are all ok. When I run the diagnostics, I consistently come up with the F32. If I clear all codes, then just turn the key on, it returns the F32 error.

When I try to go through the trouble tree, it says "Do the service now and service soon telltales illuminate during crank--Yes or No". Mine do, but the next step is "Does inst fuel economy vary while driving". Well, I can't drive it since it doesn't run.

Where do I check for voltage at the injectors. Where the injector harness plugs into the wiring harness, or at the injectors themselves?

As I said before, the car will run momentarily if I pour some gas down the butterfly. So, does this error (F32) indicate a faulty BCM or ECM? I had the BCM go out on my last Cadillac (1989), but it just wigged the dash out--didn't kill the car.

Thanks for any info!

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Where do I check for voltage at the injectors. Where the injector harness plugs into the wiring harness, or at the injectors themselves?

Unplug each injector and test for voltage on the harness side.

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

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When I run through the diagnostics, I get an F32 error (map sensor?).

F32 is the code for lack of PCM-BCM communication. That is more ominous....it may mean that the PCM is dead and that the body computer cannot communicate with it because if this. F32 is not the MAP sensor code. That would be an E32 for the MAP sensor open.

PCM/BCM? Is this the ECM? I know where the BCM is located and I thought the ECM, but what's a PCM?

Marko :o

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ECM engine? control module was replaced by a PCM powertrain control module when transmissions became computer controlled. These are loosely synonymous.

BCM body control module, on the other hand, is something else.

Bruce

2023 Cadillac CT4-V Blackwing

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If it is not the ECM, I would check the fuel pressure regulator. I was getting fire and no start on my 92 Deville, I replaced the fuel pressure regulator and all is fine.

post-3-1077663444.jpg

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If it is not the ECM, I would check the fuel pressure regulator. I was getting fire and no start on my 92 Deville, I replaced the fuel pressure regulator and all is fine.

Where is the fuel pressure regulator located? This sounds like it could be the problem. I'm definitely getting gas from the fuel pump although I've not checked the pressure (it was enough to blow a little nail out of the Schrader valve I propped open when I cranked the engine). I'm getting 12 volts to the injectors when I turn the key on, and also when cranking. And, if I pour a little fuel down the butterfly, it'll start and run (albeit roughly) for a second or so.

So, it makes sense it could be this pressure regulator. Where is it on a 1990 with the 4.5 liter?

Many, MANY thanks for the replies. I've GOT to get my Caddy back on the road. I'm driving my son's Pontiac Sunbird, and it leaves, well, much to be desired :P

Marko

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The Fuel pressure regulator on my 92 Deville is located right of the butterfly and left of the distributor cap attached to the fuel line on one end and a vacuum hose on the other. Check the vacuum line if it has fuel in it, the regulator is bad. Mine did not but it was still bad. Cost about $95 at the dealer including tax. Take the air cleaner off and it is more visible.

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:o Does anyone have the fuel pressure specs on a 1990 Cadillac Deville 4.5 litre? I have the 1989 book, but the 89s have a throttle body, not the TPI. My 89 book says that pressure should be around 9-12 pounds, but on mine I have nearly 38 at the Schrader valve.

I'm still trying to troubleshoot this fuel problem and thought fuel pump would be the first place to look. I really don't want to start throwing parts at this thing until I know exactly what's happening.

Again, I'm getting spark and if I pour fuel down the throttle plates, it'll start and run for a few seconds, then sputter and die. I'm getting 38 pounds of fuel pressure steadily on the fuel line from the pump. I'm getting 12volts to the injectors when the key is on, yet the car will not run or even try to start.

Marko

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Then I don't know what the flip is wrong. It's getting gas, it's getting fire, but won't hit a lick. It cranks over like it's completely out of gas. The fuel pressure regulator is not leaking fuel through the vacuum line, so I really don't want to just replace that hoping it'll cure the problem. Unless it's really picky about the fuel pressure, and 38 isn't enough and it's supposed to be 50, then I'm clueless at this point. I've got a new/used PCM on the way so I'm going to try that, but if that does work it looks like it's going to be flatbed city to the local ripoff joint.

Marko

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This is out of the 90Seville/Eldo service manual. Pressure regulator: If the pressure regulator supplies pressure which is too low (below 33.4psi) poor performance, code E042 or E044 or detonation could result. If the pressure is too high, rich operation, plug fouling, code E043 or E045, poor fuel economy, and excessive odor may result.

A fuel injector which does not open would cause a lack of power or a no-start condition. An injector which is stuck partly open or leaking could cause loss of pressure after key off: long crank times would be noticed on some engines.

Also, for no start, check for blown injector fuses or blown distributor ignition fuse.

Jeff

Jeff

98 Concours

90 Seville

04 Corvette

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Wish me luck. I'm digging into the Caddy again today. I've got a fresh PCM I'm going to install to try to get rid of that communications error. If that doesn't fix the problem, it's off to the shop.

I WANT MY CAR BACK! :ph34r:

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:o This is just an update to this thread. My car lives again! It did turn out to be the PCM. I bought a used one on Ebay from a 1992 Caddy Deville and installed it this morning. The car is running great now--starts everytime.

Total cost of repair $18.00 plus many hours of diagnosis and surfing the web.

Thanks everyone!

Marko

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It did turn out to be the PCM. I bought a used one on Ebay from a 1992 Caddy Deville and installed it this morning. The car is running great now--starts everytime.

Did you remember to transfer the Memcal from your 1990 ECM? The '92 DeVille Memcal would be configured for a 2.73:1 final drive ratio (assuming it wasn't a Touring Sedan), a 4.9/4T60-E, etc...

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It did turn out to be the PCM.  I bought a used one on Ebay from a 1992 Caddy Deville and installed it this morning.  The car is running great now--starts everytime.

Did you remember to transfer the Memcal from your 1990 ECM? The '92 DeVille Memcal would be configured for a 2.73:1 final drive ratio (assuming it wasn't a Touring Sedan), a 4.9/4T60-E, etc...

:huh: Okay, please explain Memcal. Is this why my speedometer is acting so crazy now? How do I perform this, shall we say "transplant".

Marko

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Okay, please explain Memcal. Is this why my speedometer is acting so crazy now? How do I perform this, shall we say "transplant". Marko

The Memcal contains all the specific calibration information for your particular car; using the incorrect one may cause unexpected behaviour because of equipment differences. I've attached an image of a Memcal that is similar to yours so you can ID the part after removing the small cover on the ECM (1/4" head screws). Fold down the tabs on either end, and it should pop right out, almost like removing memory from a PC motherboard. During this operation, it is recommended that you keep yourself grounded since these components are sensitive to static discharge, although the risk is small because of the plastic enclosure.

post-3-1078699291.jpg

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I replaced the memcal when I got home from work today. All is right with my Caddy now. The speedometer is working properly, and I've got no codes in the computer. FWIW, this is the second computer part I've had to replace in my Cadillacs. My 89 had the BCM go south, which caused the dash to do all sort of strange things. The 90s PCM caused it to die completely.

Many thanks to all on the board who answered my questions and put my trusty Caddy back on the road again!

Marko :)

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