An Ongoing Problem...

[Cory Wolfe]

Alright, ever since I had my Millenia, it idled a bit rough as the engine seemed to miss. However, once moving and pressing the accelerator, it stopped and ran perfectly. Well, every once in a while it would suddenly run as if a spark plug was bad. It would bog down, but still be driveable, barely. Then it'd suddenly stop. I thought maybe the fuel injectors were dirty and possibly clogged so I tried some of that STP fuel addictive made for that. No real effect. Lately, I tried changing the spark plugs to some Bosch Platinum 2s. Still no real effect on any of them, but luckilly it has yet to get into one of its bogging down fits. The missing is getting worse, however. It now will do it at certain times while in drive (like giving it gas after cruising, or while cruising). My question is, what could it be? Next on my list to change is the air filter and hose assembly (its cracked with a gaping hole, but wrapped with electrical tape. Otherwise, IDK what to check out. I'm thinking of something with the fuel injectors or fuel filter. Any help?

[Delta Force79]

Sounds like either the fuel pump is going or the fuel filter....also it could be your timing is off...just my guess....I would try the easy stuff first and check the fuel filter

Edited September 26, 2006 by Delta Force79

[z28luvr01]

Just for the hell of it, do a compresssion test before you start replacing too many parts. My father's car did nearly the same thing. He did a compression test and found the bad cylinder to have lower compression. The culprit - a burnt exhaust valve.

[76ChevyTrucker]

I'd definitely check the fuel pressure and do a compression test. Another thing, the Bosch plugs you have in there aren't the plugs for that car. If you do anything, I'd go buy a good set of NipponDenso, or NGK plugs and run in that thing. I've had too much bad luck with Bosch plugs in anything but an European import to run them in anything that I have ever serviced, or had to horror to drive. And the problem with the air intake hose being cracked wouldn't be a bogging problem, you'd have too much air coming into the engine, possibly leaning out the mixture and causing poor fuel economy. As far as the bogging, it sounds either like you've possibly got a bad fuel pressure regulator letting too much fuel go back to the tank and not keeping fuel pressure there at the injectors so that they can fire like they're supposed to. The regulator would be found on the fuel rail and have a vacuum line going to it. I'd check it out first and make sure that its capable of holding vacuum too, along with a compression test and a fuel pressure test.

[AAS]

Are you getting electical glitches when it runs bad? I once had a plug wire with bad insulation, and it would arc (short) on the valve cover. This made the car run with a cylinder down, but it also made my instrument cluster and stereo do wierd things.

[76ChevyTrucker]

Thanks for brining that up AAS, I didn't even think about a short, or an arcing problem from a plug wire.

[Cory Wolfe]

Just for the hell of it, do a compresssion test before you start replacing too many parts. My father's car did nearly the same thing. He did a compression test and found the bad cylinder to have lower compression. The culprit - a burnt exhaust valve.

197808[/snapback]

Will do.

I'd definitely check the fuel pressure and do a compression test.  Another thing, the Bosch plugs you have in there aren't the plugs for that car.  If you do anything, I'd go buy a good set of NipponDenso, or NGK plugs and run in that thing.  I've had too much bad luck with Bosch plugs in anything but an European import to run them in anything that I have ever serviced, or had to horror to drive.  And the problem with the air intake hose being cracked wouldn't be a  bogging problem, you'd have too much air coming into the engine, possibly leaning out the mixture and causing poor fuel economy.  As far as the bogging, it sounds either like you've possibly got a bad fuel pressure regulator letting too much fuel go back to the tank and not keeping fuel pressure there at the injectors so that they can fire like they're supposed to.  The regulator would be found on the fuel rail and have a vacuum line going to it.  I'd check it out first and make sure that its capable of holding vacuum too, along with a compression test and a fuel pressure test.

197817[/snapback]

Will do as well.

As far as the plugs, we'll see. So far I can't complain about them. I'll talk to other Millenia owners and see what they say about them. They weren't cheap, though, and can't exactly return them. I'll look into Bosch's buy back guarantee if they start to unimpress me.

Are you getting electical glitches when it runs bad?  I once had a plug wire with bad insulation, and it would arc (short) on the valve cover. This made the car run with a cylinder down, but it also made my instrument cluster and stereo do wierd things.

197854[/snapback]

The spark plug wires are sort of new, being replaced during the previous ownership. I checked them and they're all fine. I also don't have any electrical glitches.

[76ChevyTrucker]

hey vipes, you can always try the best method I know. Open hood, pull pin on hand grenade, insert hand grenade into engine bay, run like hell!

[the_yellow_dart]

hey vipes, you can always try the best method I know.  Open hood, pull pin on hand grenade, insert hand grenade into engine bay, run like hell!

199087[/snapback]

Oh... and take a video!

[capriceman]

could be a Coil pack too. since they do wear out with age. ever notice if it happens on more of a damp day then a dry day?

[Intrepidation]

Sorry BV I can't help ya, but 76ChevyTrucker's idea is awesome!

[Cory Wolfe]

Havent really noticed a difference, but then I never thought of that.

I'm just thinking, and its probably not it, but could it in any way be the transmission? Could it be the clutch or something causing it to seem like its missing? IDK. It just doesnt seem like a miss when it does it while driving. Like, under full throttle as it goes up through the revs... It seems like it will have power surges, but the engine sound never changes. And when revving while in nuetral or park, it never misses while under throttle, just at idle. Im just wondering if it could be something related to the transmission. I'm obviously not mechanically inclined, so I may be talking out of my ass. This might be something to ask actuall Millenia owners who've experienced the tranny going (damn Ford trannsmission anyways).

I dont sound too stupid right now, do I?

[capriceman]

have you ever sounded smart? and no its not your trans. did you get bad gass or regular and then put octane boster in? since that would cause some roughness. I bet its electrical or an o2 sensoror mass airflow sensor it shouldnt be a cam or crank sensor.

[Cory Wolfe]

An update... Put the old plugs back in since they weren't that bad in the first place and what do you know, it improved. So yeah. The plugs, new and old, have deposits of some sort on it. Carbon, if I remember right, and according to the good old Haynes Repair manual, symptons are missing and such. So yeah. Everything is making sense. Hopefully, I can get everything checked out soon.

[Intrepidation]

An update... Put the old plugs back in since they weren't that bad in the first place and what do you know, it improved. So yeah. The plugs, new and old, have deposits of some sort on it. Carbon, if I remember right, and according to the good old Haynes Repair manual, symptons are missing and such. So yeah. Everything is making sense. Hopefully, I can get everything checked out soon.

203355[/snapback]

Those are great manuals, I have one for the Shadow and the Prizm.

Edited October 10, 2006 by Dodgefan

[Guest YellowJacket894]

You know, the 3400 in our Impala does almost the same thing. The engine never quits or bogs down, but at idle, the car seems to miss and then that stops once you get going.

Ah. Doesn't matter anwyay. We're getting rid of the car probably this Saturday. Along with the wierd engine quirk, we think the transmission is going out. When you shift out of park, the car jerks pretty bad and it also tends to delay upshifts and downshifts. Add to that the speedometer cable broke two months ago and the dealer simply refuses to put a new one in and insists on a whole new f@#king cluster, well, you know.

That Impala was built on one of Oshawa's bad days. I hate to say it, but I'll be damn happy to see it go.

Edited October 11, 2006 by YellowJacket894

[Northstar]

It sounds like the camshaft is off or something to me, but I'm probably just guessing that because I know how a cammed car idles. My car is tuned pretty well so it's not that apparant, but you can still tell its there, and I've heard other cars that have performance cams that almost die when at idle.

[76ChevyTrucker]

Yeah, that's one of the high-lift, long duration cams that you're talking about North, it has such a large profile that the engine "lopes" along like its going to die because there's such a huge distange between when the intake valve opens and when the exhaust valve opens.

[Cory Wolfe]

Ah. Doesn't matter anwyay. We're getting rid of the car probably this Saturday. Along with the wierd engine quirk, we think the transmission is going out. When you shift out of park, the car jerks pretty bad and it also tends to delay upshifts and downshifts.

203424[/snapback]

It probably is. My Ford sourced tranny is starting to go. It's actually been good considering it is the original tranny and has 169k on it. Most Millenia owners report having to change the tranny much earlier than that, course, maybe it has to do with which engine its hooked up to since I didnt read into it too much. Oh well. But yeah, it shifts out of park hard too and will sometimes shift hard and delay shifts. Otherwise, though, it's a good transmission. The shifts are usually smooth and perfectly timed, and the hold feature is awesome. Can almost shift it like a manual...