Jump to content
CaddyInfo Cadillac Forum

hard starting HELP


SteveK

Recommended Posts

I have a '97 DeVille base model. I have posted on my problem before and have received very good advice. Unfortunately nothing so far has worked. The problem is this. After my car sits for more than ten minutes it takes a good five seconds of cranking to get it started. It doesn't matter if the engine is warm or cold. At first I was directed to leaky fuel injectors (causing a flooding condition). I have checked and the injectors do not leak. I replaced the fuel pressure regulator, had the entire fuel system flushed and the injectors cleaned. I was then directed to a bad fuel pump. I was only getting around 40#'s when it should be 48-55#'s. Well I just replaced the fuel pump along with a new inline fuel filter. Still no change; the hard starting remains. Occasionally I get a split second of what seems to be no fuel while driving or hesitation. Almost like the fuel was cutting out, just for a second. My mileage sucks. I get around 12mpg in the city and 16 to 18 on the highway. I've changed the plugs, wires, new battery, oil and cleaned just about anything I get take off and clean. I'm really at a loss. I throw myself on the mercy and experience of the group.

I mention one more thing. I have read in different postings of this group that an aftermarket radio can play heck with the "brain" of this car. The previous owner put in a high quality after market radio but after market none the less. Could this be a problem?

Sincerely, Steve Keitel

Link to comment
Share on other sites


If the car was starting and running fine and then developed this problem suddenly, I doubt the stereo has anything to do with it. That would have most likely caused problems right after it was installed. Have you checked for diagnostic codes? It seems like the crankshaft position sensor could be a likely culprit. If one of them is bad it will cause hard starting or no starting at all, and will often cause stumbling, hesitation, and sometimes stalling while driving, particularly during acceleration. A bad crankshaft position sensor will normally set a code.

big4870885.jpg

Link to comment
Share on other sites

A CKP sensor should not affect mileage though and '97's where not known for them (not saying that they are incapable of failure). These symptoms just don't sound like CKP sensors to me. No MAP or MAF sensor codes?

Link to comment
Share on other sites

I didnt see mention of codes, have you checked for codes?

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

Link to comment
Share on other sites

A CKP sensor should not affect mileage though and '97's where not known for them (not saying that they are incapable of failure). These symptoms just don't sound like CKP sensors to me. No MAP or MAF sensor codes?

I agree a CKP shouldn't affect mileage. I just recall that on a car I worked on a couple months ago (2002 Oldsmobile Intrigue. Not a Caddy I know, but still.) these were the EXACT same symptoms (except the mileage) it was having for about a month before it finally wouldn't start one day, and the SES light came on with a code for the CKP. It never set a code until that day. After it was replaced, all of the symptoms went away. That's why I said it COULD be a likely candidate, though that doesn't mean it IS. As for it not being a common problem on the 97, that I wasn't aware of. I was basing this on my general car knowledge and past experience.

I think checking the DTC's is definitely the best place to start. Given the symptoms described, I doubt that there would be no codes. MAP and MAF sound like good possibilities too.

big4870885.jpg

Link to comment
Share on other sites

As others have said, check the codes to see if they may provide a clue to the problem area. Also, what is the fuel pressure while cranking the engine? When you changed the fuel pump, was it a pump only or the entire sending unit? If it was just the pump only, there may be a split in the line between the pickup and the pump.

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

Link to comment
Share on other sites

As for it not being a common problem on the 97, that I wasn't aware of.

Carla, the reason I said that is because GM had a bad supplier (Siemens in Mexico) and virtually all 2000- early '03's had bad CKP sensors. They switch to Denso in Japan and the problen seemed to go away. The problem was almost unheard of before 2000.

Link to comment
Share on other sites

As for it not being a common problem on the 97, that I wasn't aware of.

Carla, the reason I said that is because GM had a bad supplier (Siemens in Mexico) and virtually all 2000- early '03's had bad CKP sensors. They switch to Denso in Japan and the problen seemed to go away. The problem was almost unheard of before 2000.

Ahhh. Gotcha. Good to know.

big4870885.jpg

Link to comment
Share on other sites

I just had the codes checked and I have the following:

P0171B

P0174B

P0151

I also checked and I am getting spark to the plugs. I also checked the fuel pressure now that I just got the fuel pump and inline filter replaced. It reads 46 pounds.

My mechanic recommends a smoke test to check for vacuum leaks. This will be performed later this week unless anyone can come up with an answer before that.

Thanks in advance! Steve Keitel

Link to comment
Share on other sites

I figure the O2 one means I need a new O2 sensor unit but what about the lean banks? What causes them, are they the cause of my problem and how do I fix them? Thanks, Steve

A couple of the first things I would do, is check to make sure that the intake is tight.

Check the plenum between the throttle body and the intake and check all the vacuum hoses you can get to.

The low voltage on the o2 sensor could be a frayed or burnt wire.

It "COULD" be the o2 sensor, but I would check all wiring and connections first.

Posted Image
Link to comment
Share on other sites

I don't believe there is a plenum in 1997 but you have a vacuum leak that is affecting both banks, check the TB tightness and seal to the intake, the brake booster hose, intake bolt torque and check it for cracks and all vacuum hoses.

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

Link to comment
Share on other sites

Bad news. My mechanic just performed a smoke test to find the vaccuum leak. He said there is a big leak in the intake manifold. Also, just yesterday my "check coolant level" warning message came on. Since the coolant isn't leaking out of the engine I can only assume it is leaking inside. Anyway, the mechanic looked up the part(s) and said that the intake comes as a kit with the injectors and the rail. Is this correct? Do I have to buy a kit for $650.00 or can I just buy the manifold? I love my car but it is becoming a real money pit. I would appreciate any advice that would save me some money. Thanks, Steve Keitel

Link to comment
Share on other sites

Bad news. My mechanic just performed a smoke test to find the vaccuum leak. He said there is a big leak in the intake manifold. Also, just yesterday my "check coolant level" warning message came on. Since the coolant isn't leaking out of the engine I can only assume it is leaking inside. Anyway, the mechanic looked up the part(s) and said that the intake comes as a kit with the injectors and the rail. Is this correct? Do I have to buy a kit for $650.00 or can I just buy the manifold? I love my car but it is becoming a real money pit. I would appreciate any advice that would save me some money. Thanks, Steve Keitel

Where is this leak and why do you have to replace the manifold? I see no reason you can't buy a manifold alone.

Link to comment
Share on other sites

Do not assume ANYTHING about the coolant usage at this point.

As far as the vacuum leak at the intake manifold goes - what is leaking at the intake manigold? The gaskets between the intake manifold and the heads? If so, that is a very easy fix. If the intake manifold is cracked, I'd look at buying a used one and transferring the existing fuel rail to the new "used" manifold before I'd pay $600 for a new one.

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

Link to comment
Share on other sites

I agree, where is the leak, is it cracked or is it the intake manifold gaskets or backfire port...

Someone is BSing someone.... Each injector is about $55 so 8 injectors alone would be $440, just for the injectors not including the rail that is $230

I would get more info from him on what is wrong and check scrap yards for used intakes, www.rockauto.com does not sell intakes for some reason, but I would price them if I were you, I believe that intake manifolds are very expensive

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

Link to comment
Share on other sites

  • 4 weeks later...

here's an update on he hard starting problem. After thousands of dollars and hours and hours of repairs it wound up being leaky fuel injectors after all. I originally tested for leaky valves but evidently did not leave them disconnected long enough to show a leak. Anyway, after repairing a large vacuum leak and replacing all the injectors it starts like a champ.

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...