OBD codes P1029 and P1031.....

[vegasjetskier]

Did you test the #5 fuel injector?

No I haven't. After reading the Volvo info on AllDATA, if the coil pack and/or injector were causing a misfire, there should be a trouble code indicating a misfire. Given how rough the engine idles and if it was a misfire then a code should have been set.

The car has been out of commission for about a week now ...and it will need to be towed to the shop as driving it the distance would not, in my book, be wise. I'm not so sure tearing into the injectors would be to my benefit. I may invest in a "noid" light to check electrical impulses but I'm not going to go much further.

The majority of the codes set so far have centered on the ETM and either faulty signals or internal faults.

OK, that's reasonable. I'm just curious why #5 seems to not be firing. Let us know what you find out.

[MikesS70]

OK, that's reasonable. I'm just curious why #5 seems to not be firing. Let us know what you find out.[/quote]


Well, under the category of "All is not as it seems" ...#5 may very well be firing. If the ECM and throttle are getting bogus info/corrupted signals that, in turn, may be causing the fuel system to act strangely possibly running a too rich or lean mixture ....don't know just a guess. But after reading the info available through the AllDATA subscription, there's a whole lotta stuff goin' on and a whole lotta areas to poke into.

For instance ...this car has what are called "air shrouded injectors" (which is why you can't readily find replacements on line and why when you do they are supremely expensive ...like almost every part on this car). There is a special control valve in the intake duct used to admit the shrouding air to the injectors ...this valve, a gate type valve, doesn't just simply open or close (oh, no) ...it constantly vibrates open and closed and, depending on the signal from the ECM, this vibrating frequency is what controls the amount of "shouding air" drawn by the injectors. This is sort of like a high tech AIR injection emissions system ...and it operates at various times (like cold starts). Yikes....

So I've given it the college try but I can see where even an experienced mech *needs* to have that VADIS system and hardware to figure out what the blazes is goin' on ...or not.

Mike

[MikesS70]

An update on the continuing saga...

This morning I went in search of a potential repair shop; checked out two with one making the cut. Also gave a call to the ex-Volvo dealer (nee Subaru dealer). Turns out the Subie dealer still works on Volvos and can do everything (including factory software downloads) except factory warranty work ...not a problem with a '99.

Put the S70 back together and brought it out of the garage (the engine still running like its got a cylinder miss). I decided to give it a test drive; it was in a "limp" mode as the engine would not rev past 2K RPM ...about 30mph max ...drove it down to the end of the cul de sac and back parking it in front of the house ...I could get it to the ex-dealership under its own power.

Three hours later, wife is home (to follow me) and I head off for the shop. Car starts *and runs normally*(!). On my way to the shop I notice some hiccup/surges when moving off from stops and some skips (like the tranny shifting) when cruising. There is a vague feeling that the engine is not quite responding to the actions of my right foot. The CEL is illluminated.

I explain my symptoms and the codes I've downloaded to the service writer and he is 99% sure its the ETM ...very common symptoms associated with impending failure of the unit. I asked about the rough idle and he said that, yes, this was indeed a common symptom of the ETM failing. Essentially the ECM has lost communication with what the ETM is doing and cannot send correct fuel metering ...ergo the rough idle. It would also go along with the trouble codes I have downloaded ...all dealing with the throttle unit and ECM signal faults with *no* misfire codes.

The shop will be running a full diagnostic on it tomorrow. I'd like to get a print out of the readings....

And while it's in the shop, the timing belt is being swapped. Wouldn't you just know that Volvo I-5 is an interference motor??? Blow a belt and trash your engine ....might as well make beer cans out of it then....

Mike

[vegasjetskier]

Wouldn't you just know that Volvo I-5 is an interference motor??? Blow a belt and trash your engine ....might as well make beer cans out of it then....

Mike

Yeah, you'd think with all their engineering prowess they'd be smart enough to put 4 little divots in the top of each piston to keep your valves from breaking off. But, that's too much to ask . . .

[MikesS70]

The ETM was swapped ...just made it under the ten year limit by *two* days. Had to have my car taken to a "real" Volvo dealer to do the installation (vs the ex-dealer now Subie seller). Apparently the service rep I spoke with was a little misinformed about being able to get Volvo software downloads for a new ETM. Fortunately I've kept a towing endorsement on the S70 so the most it'll cost is $50 ....not too bad for a job that was gonna run over a grand. I'd've given serious thought about going with the moded original ETM if we had to pay for it.

Thanks for all your help.....

Mike

[vegasjetskier]

Glad you made it under the wire! Is the car running good now?

I still wonder what made the #5 cylinder get so hot it destroyed the spark plug. I guess we'll never know . . .

[MikesS70]

Glad you made it under the wire! Is the car running good now?

I still wonder what made the #5 cylinder get so hot it destroyed the spark plug. I guess we'll never know . . .

Very strange ...yes. My theory is the plug rattled to such an extent that the ground electrodes simply broke off ...possibly over time vs. all at once. In fact the ex-Volvo dealer service rep suggested the same thing before I voiced my theory. The plug and coil did remain functional possibly arcing from the center elctrode to the lower plug case. I'm pretty sure the failure wasn't caused by a lean condition because the ceramic plug nose looked very similar to the others as far as its color goes ...it just didn't have any grounding electrodes.

But like you say, we may never know for sure. What *I* know for sure is I'm sticking with the tried and true RC9Y Champions unless I can readily find the Bosch OEM plugs.

Mike