04 XK8 90 kmiles. Sorry to keep asking stupid questions, but search isn't panning out well for me. While in a 5 minute idle situation, engine was idling rough, bucking a bit. Kicked it out of gear, kicked throttle quickly, didn't seem to help any. While driving away from idle situation, got Restricted Performance message, no CEL. A minute later the CEL started flashing I've seen the message (related to lean bank/injector o-rings) and I've seen the CEL on solid, but had not seen a blinking CEL. Drove it home, running fairly rough, parked it, grabbed the EBS (Emergency Backup Saab), went to work. Checked codes today and: nuthin'. Just the standard P1000 code. Cleared codes. Started: still idling rough, still saying restricted performance. Read codes again: still nothing but P1000. A) what does a flashing CEL indicate (I interpreted it as a dire indication). B) why no codes?

 

Mine did that when I had a flakey coil, didn't throw a code until it failed more solid. And I have an EBS now also..



Dave

 

A) a misfire serious enough to render your cat. converters scrap in short order. Stop driving the car immediately

B) Not all readers can display all codes.

 

So I'm supposed to have it trucked to the dealer? All it did was idle roughly. This seems more than a little bizarre. My reader is an Actron CP9580A.

 

Yes the flashing CEL is the impending doom warning and misfires can destroy the cats. I had it flat-bedded home when it misfired and didn't clear up. I only drove it for diagnosing until I got it figured out. All in all I had THREE bad coils contributing to it. My cats seemed to have survived but I only ran it to test repairs. And even when it did throw codes it kept saying it was cylinder 8 so I replaced its coil, injector and all the spark plugs all to no avail, turns out all 3 bad coils where on other cylinders so the code it was throwing was useless.



Dave

 

Most codes are 2-trip and clearing goes back to 0 trips.

If you're inclined, check all coils & plug wells, check fuel trims and any other things that seem worth doing. Read up about misfires and also about flashing MIL. Get a feel for what was tried / worked.

 

Yeah, after just a few seconds to a minute of idling I notice that the basic tests come up as incomplete. The hell??!! I'm not supposed to drive it for fear of damaging the cats, but I can't generate codes unless I drive it! Classic catch 22. What constitutes a trip? Can I get by with cheap ignition coils (Ultra Power from Rock Auto @ ~$28)? Surely they're OK for t-shooting purposes, but can I rely on them for long-term use?

Seriously, I have a car that's clearly missing and generating dire warnings, but I have no codes. What am I supposed to do here?

 

If its a coil that isn't solid failing or multiple flakey coils like mine was the ECU seems to get confused and either give the wrong info or none at all. Mine eventually started coming up with cyl 8 each time but none of the bad coils were in cyl 8. I ended up swapping them a couple at time with new ones until obvious changes happened. I finally just replaced all the original Denso's so I wouldn't be do this again a month later. The Densos must have timers in them as they started failing literally when the odometer turned 100k.
Also look for oil or coolant in the plug wells and damaged coil connecters. Be aware the insulation on the 20 ga wires going to the connectors can get brittle and fall off and short. I ended up using silicon to hold what was left of the connectors on and had to use heat shrink tubing on some of the damaged wires. You can also replace the connecters but I am cheap and they cost near as much as the coils.


Dave

 

You're confusing two different things. The 'basic tests' are the system monitors (not the engine or car) that are going through a self test cycle. That might take 100 miles of driving.

An actual engine fault should show immediately.

 

I know the "basic tests" are a different thing. Still, I wonder what constitutes a "trip" for the purpose of generating codes. I'm inclined to get 4 of the least expensive ignition coils and install them all on one bank. If no change, replace originals and install the new ones on the other bank. If no change, move on to other things. Inspect wiring, wells, connectors along the way (of course, I'm going to break the blasted connector retaining tabs in the process, I'm sure). I really don't think it's mixture related - at this point it's a hard miss at idle on one cyl. And I'd be surprised if it's a plug - seems too sudden, and I'd expect a bad plug to act up at high RPM/high load. Thanks all for your tips.

 

It's the kind of question whose answer is learned by trained techs, is not typically of interest to an owner, but can be researched on the net

Trip is short for warm-up cycle. Warm-up is defined as ... well, same answer.

Incorrect but workable is engine cold to hot.

---

Then you need to understand when codes can flag and that is complex because otherwise you'd have endless codes all the time and would think the car never worked. Instead, codes flag almost per the way an engineer steeped in cars would expect (this will never be a perfect thing as engineers have somewhat varying opinions).

---

The trained techs know all this and a vast amount more - it's what you're paying for when you go to them. Getting it all free at no effort on a web site is somewhat optimistic and lucky if it occurs.

---

I suspect the techs would try to save the cat(s) by taking things apart and looking/testing or would know for the car concerned how big they felt the risk was. You might check the coils, plug wells, do basic circuit tests on wiring, inspect connectors, etc. Depends if you want to spend time and effort or pay a tech.

For sure, downloading and spending time studying the workshop manual would be a given.

I wouldn't fit any crappy parts but it's your car...

In many cases a code is really helpful and gets you to a cause and fix quickly. Not every fault can cause a helpful code quickly so then real trouble shooting and knowledge turn out to be useful.

If you're in a hurry and want to skip the time and effort, find a tech