OBD-II Code P1374 on a 1996 Olds Cutlass Ciera 3100 (rough idle/skip/dies)

Page 1 of 3  
This car has been driving us crazy. A couple weeks ago the car conked out, we gave it a full tuneup (pcv plugs wires fuel filter air filter serp. belt) and it got running again. It started off with 4 codes in
the computer, one of which was the MAP sensor (since replaced) now we're down to this annoying P1374 code we can't seem to track down, and we're at the point now where the car has a rough idle/skip and if you give it some gas then let it return to idle, it'll die (you can rev it for awhile no problem, as soon as you stop and it goes back to idle, it just quits). We've replaced the crank sensor and the coolant temperature sensor as well. The last 2 things we've been told to try are the ignition control module and the harmonic balancer. If neither of those 2 things solves it, we're at loss. Any ideas are appreciated, thanks.
-GV
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Does this skip/stall at idle affect performance driving at nomal speed/loads? Is this a constant misfire, or just a rough idle stall,? If so check the egr for not seating, remove and clean, try running the car with the connector off. Does this stall happen from the first cold start or only after it warms up. Have you cleaned the throttle body and iac for carbon accumulation, check for vacuum leaks especially around the throttle body, continually replacing parts is not the answer here, the base problem must be found, it is possible you may have to consider getting this to a pro who is familiar with these type problems.

-
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
http://users.eastlink.ca/~smackie/p1374.pdf
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Interesting stuff, thanks.
-GV
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 27 Oct 2005 17:01:14 GMT, "Steve Mackie"

You don't happen to have the "Wiring Repair in Electrical Diagnosis", or equivalent, do you?
-GV
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
maybe you should consider the conditions/actions prior to/during the conk out.for clues.and fuel pressure.anybody put additives in tank prior to conkout.can mess with injectors.how about injector voltages/pulses.did you say it ran better with replacement ICM?where did it come from?was the swap not available?(sure thing proof).you coulda got another bad one?change the computer?popping cyl means misstimed fire or lean mixture.like i said before.all kinky Gm problems for me have either been ICM ECM or injectors for the symptems you describe.but he first question i always ask anyone is if car has recently been worked on or any special things been done out of the ordinary.and then ask conditions during problem developement or event.i remember a vw golf my daughter had that had a rough intermiitant idle and stall problem and i finally after 6 months got a sub computer to try and when i pulled the large connector i saw one of the wires had come untrapped from the connector and so was making intermittant contact .WHO KNEW!!and it was smothered in grease but i still caught it!of course this was while removing test computer that failed to fix problem!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I highly doubt a fuel additive would be throwing a P1374 code.

Slightly better with the new ICM however the symptoms have not changed, the problem still exists. Came from autozone, brand new.

Highly unlikely, this wasn't a pickup from a junkyard this was a brand new part.

That's the last thing we want to do. A *new* computer is $350 and would need to be reprogrammed.

For the symptoms, AND a P1374 code, though??

Nope. Car had just passed inspection and had an oil change, actually.
After it started this problem and the check engine codes came on the first time, we gave it a good tuneup (as per my original post) plus we replaced the MAP sensor due to a P0108 code (IIRC). As I posted already, this is either a wiring/terminal problem we are going to attempt to trace down, or it's the computer. It doesn't appear to be the ICM (as this did not solve the problem and the P1374 code is still there) and it's definitely not something as over-simplified as just someone adding fuel injector cleaner.
-GV
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Not sure what you mean.
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I got a hold of the GM troubleshooting rundown, which looks just like the alldata steps, except in some steps it says something like "refer to the Wiring Repair in Electrical Diagnosis book" so I was wondering if you had such a thing. At this point it's looking like there's a very complex electrical problem we need to attept to trace down, or the computer is bad :(

-GV
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Gotcha. If you have the factory manual set there is a book dedicated to Electrical Diagnosis. The wiring repair you speak of is just a section detailing repair procedures. Nothing specific to any circuit. I can turn the ALLData version of the same thing in a PDF, but it's not going to help you until you find the problem.
...or if there is a specific piece of information you need, I could send that over...
Steve

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Sorry I can't be more specific, I'm just reading what the printout we got from the GM dealer says. Anything you can post would be helpful and much appreciated!! :)
-GV
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You know, I just can't f'n win. Went to the library today, they have all the mitchell manuals EXCEPT the one for 1996 in one section, and in another section they have mitchell manuals that have these wonderful wiring diagrams that would probably be great EXCEPT the thing is in this big binder and none of the librarians know how to undo it to make copies, because you can't take it out of the library!!
-GV
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Use a digital camera and photograph the pages. Also a trip to www.helminc.com might be in order. If you plan on keeping the vehicle and fixing it yourself a good set of factory manuals is well worth the investment....

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
how much does the boneyard want for a puter.and why did the wiring problem suddenly develope?connectors?corrosion?chafing?insulation failure?constant flex internal breakage?unbelievable fluke?(my VW)if you were able to cure the other codes it does seem like a funny deal.wonder why the new ICM only improved the running.can new parts be faulty.it does happen occaisionally.maybe i'll go study that 1374 repair tree.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The answer to all your questions is: I don't know. The car was running fine when my friend first got it, all of a sudden the check engine light came on and it started running like crap. We have not yet ruled out a wiring problem or a computer, yet. We got past step 4 in the alldata chart posted by Steve Mackie, now we are on step 5 (that means we did not skip to step 8 if you are following along). Simply ran out of time tonight, will be working on step 5 in the coming days.
-GV
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
well if i'm understanding this 1374 thing(pdf)so far your car is currently running on the 24x reference signal(crank sensor) and cam signal.1374 means the ICM is ignored(3X) as an input to PCM.so then why did the car run better with a new one?hmmmm.and even without ICM input car should start and run on 24x and cam signal.you replaced the crank sensor.you joked about the cam sensor.hmmmm.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

After lots and lots of frustration, I believe we've found the problem, it appears to be a bad wire. The circuit 430 wire, purple/white, has no continuity. That's the 3x reference high signal for those following along at home. And, obviously I got my hands on the wiring diagrams (finally) or else we never would have figured this out.
Now of course, the question is, what type of wire is used, what gauge of wire is used, and how in the hell are we gonna run the wire from under the hood to the inside of the car? And after all that, is this finally going to fix the problem...I certainly hope so.
-GV
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
have the same problem did everything on the list except for the manifold have you fixed the problem yet and if so what was it?????
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Driving? What do you mean driving? We can't even drive this thing, as soon as you take your foot off the gas, it dies :)

Constant, you can definitely hear the skip when you rev the engine.

Both. Have not checked EGR yet, thanks for the idea, will add to the list.

Yes, as part of the tuneup the intake was cleaned out with carb cleaner. Have not found any vacuum leaks yet. This thing will be either fixed or going to a pro soon before we rip the rest of our hair out!! :-)
-GV
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
GlassVial wrote:

Have you checked for a leaking intake manifold gasket? They fail all the time on the 3.1/3.4 l GM engines and can cause all sorts of weird problems. Also check carefully for any signs of water in the oil. The first place it becomes visible is as a milky sludge on the underside of the oil filler cap.
John
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.