[Ranger]

Oh shit, you're right. You through us off track with the diagram you posted. I suppose there is a chance you have two bad coils, one in each ignition cassette (OR two faulty, or clogged injectors).

 

[basscatt]

I will only say this one more time -

you ran the BLOCK TEST - AND FAILED -

I wouldn't invest a single penny into ANYTHING -
until you decide whether or not you are going to fix the head gaskets -

good luck -

 

[Submariner409]

My bad on the diagram .............. but read Post #38 again.

The coolant reservoir pressure detour - the fact that you can now drive the car and system pressure goes to ~16 - 18 psi is good. Normally (abnormally) a bad head gasket (in advanced stages of failure) will overpressure the cooling system and blow off coolant quite regularly. If you continue to mysteriously lose coolant, you're back to basscatt's interpretation of the block exhaust gas test. My opine is that if head gasket failure is progressing then it's very curious that a cylinder in each bank, in the firing order noted in Post #38, would lose power - this says both bank gaskets are failing at the same time. Weird.

 

[Ghostsoldier]

I will only say this one more time -

you ran the BLOCK TEST - AND FAILED -

I wouldn't invest a single penny into ANYTHING -
until you decide whether or not you are going to fix the head gaskets -

good luck -

Again, basscat, I appreciate your knowledge and guidance. To be perfectly honest: if it's a head gasket problem, then no, I won't be investing any more $$$ into this Eldorado. I'll sell it as-is, or park it in my backyard corral for future use, then and go pick up the car I really want (and can work on with my tool box, without needing anything electronic or handheld), a 5th generation ('65-'68) Cadillac with a 472.

I've had my fun with this car, but I'm not sentimental...if it's going to give me this much trouble, I don't have the time, desire or money to keep investing into it...I'm an old-school, non-electronics V-8 mechanic at heart, and that's where my loyalties lie.

But, all that above being said, I'm still intrigued as far as solving the problems I can with this car, before I have to sell/retire it...hence this update.

Today, I rented the noid set, and found out that all my injectors are getting fire perfectly, so the PCM and/or signal issue is out. I also pulled both non-firing injector plugs (since they aren't working, anyway) and drove it down to O'Reilly's to have them run the code scanner again...same as last time, "random misfire detected".

I picked up a set of 8 N* injectors off a guy on the Bay for 20 bucks, and some new o-rings....I'm going to replace the two questionable ones this week, and see what happens.

I also found 6 N* coil packs at the local junk yard, at 30 bucks each; I'm going to swap out the injectors first, and then if that doesn't work, I'll buy 2 of the coil packs and replace mine, and see if that works...all said and done, I'll only be into it a further 90 bucks or so, and that will satisfy my curiosity.

Rob

 

[98cadillac]

Re: Rattling/thumping on floorpan, Check Engine (SES) light

...
Also, the "Check Engine" light starts to flash when I'm pulling up hill, or if I gun the accelerator...if I take it easy and baby the gas pedal, it's not as bad, but it's still there, and it will eventually go off (until the next hill).

And, call it weird, but I can definitely 'feel' a difference it how the car runs...it's not up to it's usual N* par, if that makes any sense.
...
Rob

When one of the coil packs in my 98 Seville STS was bad, I had similar symptoms. My car would buck and jerk when I accelerated briskly, and the check engine light would flash.

Mine has the 4 coil packs at the top back of the engine (not the cassettes), and I was lucky to have a hint as to which one might be bad when I saw the corroded connector on top.

 

[Ghostsoldier]

Tell me about it; with 2 injectors not working, I've got a V-6...and, it's not even firing in a diametrically opposed state, so it runs like a pulpwood truck!
Rob

 

[Tankboy40]

I'm really looking forward to seeing how this one pans out... keep us posted and good luck!

 

[Ghostsoldier]

UPDATE:
After checking the input using the noid, and finding that all the injectors are getting fire, I replaced the 2 non-reactive injectors with the ones I bought off of eBay....and it didn't help one iota.

Sooooo....here's what I've deduced: The injectors are getting fire; the injectors are squirting fine; so, that means that the raw fuel in the chambers are not being ignited by the plugs. I have brand new AC plugs, plus brand new COP boots, so the only logical culprits now are the coil packs, or the ICM's in the coil packs.

I'm heading out this afternoon to the boneyard to pick up a couple of coil packs, plus maybe an extra ICM or two while I'm there.

Another question that comes to mind is the PCM...would a faulty PCM cause the plugs not to fire? If so, can it also be a "plug-and-play" junkyard fix, buy picking up a spare one?

Rob

 

[Submariner409]

The PCM is the "processor" for ignition signals pulsed by the CKP's and CMP. We have seen two or three in here over the years that have had problems. You might want to do some research into PCM recalls for "loss of ignition signal". My car had it done in mid-2002; not sure if the recall applies to 2000............ It was Recall #03005.

In any event, a new or used PCM must be programmed by a GM dealer for YOUR car - the thing is totally car-specific.

 

[Ghostsoldier]

Thanks, Sub...I checked for recalls, and except for some inner tie rod looseness issues (where they could fall off at highway speeds and kill me, apparently), I could find nothing linked to the PCM (although I did find the one in 2002 you spoke of). Picking up a spare PCM won't work, so I'll skip that.

I drove an hour to the boneyard, only to find they closed early (website says 6pm; handwritten paper note on gate said 3:45pm...I got there at 3:50 and the [email protected]&%@! wouldn't let me in)...so, I'm going back tomorrow morning.

As far as the coil packs go, however, I do have a question: Since the cassettes have no moving parts, and I'm assuming the coils themselves are just wound wire epoxied inside a chamber with a COP contact sticking out, is it possible that the ICM is the only faulty part on the cassette assembly?

If it is, then I'll just buy a couple of those; if the coil pack itself can (and does) go bad, I'll buy the whole thing...the difference in $$$ is 30 bucks for the whole cassette, 12 bucks for the ICM....I've googled to find a test method, so I could check them out at home with my multimeter, but I can't find one for the Northstar.

Rob

 

[Submariner409]

Get the whole enchilada - sometimes the coil secondaries (many feet of hair-thin coated wire) do burn out - regardless of potting.

 

[Ghostsoldier]

Roger that, Sub...will-do.

I don't know if it matters, but my old cassettes have fine, hair-thin cracks across the outside plastic walls of the epoxy chambers, and the COP stud towers, too....I think 6 of the 8 on both cassettes are cracked.

Rob

 

[basscatt]

Roger that, Sub...will-do.

I don't know if it matters, but my old cassettes have fine, hair-thin cracks across the outside plastic walls of the epoxy chambers, and the COP stud towers, too....I think 6 of the 8 on both cassettes are cracked.

Rob

--------------------------
what you COULD do - before driving an hour to the bone yard -
is to swap the two coils front-to-back -

your previous #5 misfire should become a #4 misfire -
IF the rear coil is the problem - which I believe it is -

which is what I suggested back on post #25

 

[Ghostsoldier]

Bass....I did that last week, drove it for about 5 days, and then took it back down to O'Reilly's to have it read again...I got the same P0300 "random misfire" code; it could not pin-point the cylinder again.

Now, since I've swapped the cassettes, I have 2 cylinders that don't seem to be firing...not that I think the swap caused it, but it went from one cylinder (No. 5, rear bank) to two (No. 1, rear bank and No.4, front bank). The No. 4 miss is the consistent...it's opposite of No. 5 on the coil, which makes sense....but, the No. 1 not firing is a mystery to me.

That's why I thought replacing both cassettes would be the best route, at this point.

Rob

 

[Ranger]

Rob, for what it's worth my money is on one of the coils. ICM is a possibility, but I'd guess not as likely and the PCM is even less likely.

 

[Ghostsoldier]

Yeah, I appreciate the advice, Ranger...I'm going to buy 2 of them; it's only 60 bucks (with a 7-day return policy), and I really can't go wrong there.

I'll let you guys know what happens tomorrow (I'm off for the holiday).

Rob

 

[Ghostsoldier]

UPDATE:

Bought 2 near-pristine cassettes today from a '00 Deville for 70 bucks, installed them, and was instantly disappointed; the sonofabitch still misses...seems a lot worse to me now, too.

Boy, am I ever P.O'd....:banghead:

I am now officially at a loss; the only thing I can think that would be different, is the ICM's in the Deville cassettes; like the PCM, I'm not sure if they are tuned specifically for the Eldorado?

If so, the goods news is, I save both of the ICM's from the old cassettes (which I had to turn in for cores)...if they are indeed tuned for individual cars, I can put these in the cassette bodies and try it again.

If not, I'm totally, completely bum-fuzzled here...I can't think of anything else that would be causing the problem.

Rob

 

[Ranger]

Doesn't the ESC have the same LD8 engine as the Deville? If so there is no difference in tuning. Even in the case of the ETC I think the difference is in the PCM.

 

[basscatt]

UPDATE:

Bought 2 near-pristine cassettes today from a '00 Deville for 70 bucks, installed them, and was instantly disappointed; the sonofabitch still misses...seems a lot worse to me now, too.

Boy, am I ever P.O'd....:banghead:

I am now officially at a loss; the only thing I can think that would be different, is the ICM's in the Deville cassettes; like the PCM, I'm not sure if they are tuned specifically for the Eldorado?

If so, the goods news is, I save both of the ICM's from the old cassettes (which I had to turn in for cores)...if they are indeed tuned for individual cars, I can put these in the cassette bodies and try it again.

If not, I'm totally, completely bum-fuzzled here...I can't think of anything else that would be causing the problem.

Rob

---------------
it is possible that either one - or both the cassettes you just got could be bad -

the ICM rarely goes bad - but it is easy to change -

all the ICM's and coil cassettes are the same -

whether from a Deville - Seville - or Eldo - VIN 9 or VIN Y -
they are all the same -

I'm totally, completely bum-fuzzled here...
I can't think of anything else that would be causing the problem.
could be the coolant in the cylinder has the spark plug so wet it won't fire -

pull that #5 spark plug again - see what it looks like -

 

[Ghostsoldier]

Well, they gave me a 30-day warranty on the cassettes; there are 4 more at the yard, so I guess I could go by and pick those up in exchange, and see if that's the problem...it just seems odd that both coils, off the same car, could be bad.

Before I do, I'll swap the ICM's...I can do that when I get off work, pretty easily, and eliminate that possibility of having a bad one.

I'll pull that No. 5 plug and post a photo of it here later.

Rob