Jump to content
CaddyInfo Cadillac Forum

Cadillac sedan de ville wouldnt start sometimes


Sevenfold

Recommended Posts

Sometimes my 1991 Cadillac deVille 4,5 starts and can run for 5 minutes and then it just dies n doesnt start again.

Runs smooth when it runs with no missfires or so.

sometimes it start the day after like nothing has happend an runs maybe 20 minutes

when its dead all eight sparkplug has a spark but on the wrong spot...like half a lap wrong

cranksensor or ECU problem?

Link to comment
Share on other sites


You should check for OBD codes. They may tell you what is wrong. I wouldn't start buying parts until you have a better idea what is happening.

I have heard of clogged catalytic converters or mufflers that cause this problem. One of the reasons that you see humongous tailpipe openings in school buses is so that the kids can't jam a potato on them like they once did, which would cause the school bus to stall a few blocks later.

Once you have determined that the exhaust is OK, there are three things to check: gas, spark, and compression. The best time to check is when the engine stalls. Smell the exhaust and, if it smells of gas, your problem is likely the spark. If it smells hot but not strongly of engine exhaust, your mixture may be too lean, e.g. not enough gas. If the engine spins too easily when you are trying to restart, there may be a compression problem, or the throttle may be closed. Given that information, we can look farther.

I'm not knowledgeable about problems specific to the 4.5 liter, so others will likely chip in here.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

Link to comment
Share on other sites

when its dead all eight sparkplug has a spark but on the wrong spot...like half a lap wrong

Please clarify this. How can the spark be at the wrong spot? Are you referring to the actual spark on the plug itself or some sort of timing issue?

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

Link to comment
Share on other sites

I think that he is saying that the spark is firing near BDC, not TDC. If so, there probably is a problem in the distributor.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

Link to comment
Share on other sites

At that age...could be anything..

Couple of common ones..

Be sure to inspect the large battery ground mounted on the engine block near the starter.

I would also inspect the AC pickup coil and ignition module wires inside the distributor for turning green. See attached picture.

post-2-0-20146200-1393071512_thumb.jpg

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...