Missing and Bucking under load?

[Money pit Beretta]

I've done it many times, it sure saves money on Sea Foam(which I think is more of a deep clean). Steam does a good job of cleaning though.
Oh I know. That old 3.1 drove me nuts, but that was my first FWD car. I came from the days of RWD V8's, everything was easy and placed by someone with good logic.
No there is nothing to take off, just the pig tail for the sensor(be sure to do that first). By the way the bolt is metric and like 8mm or 9mm(it's been along time).

[GTU89]

I think I'm gonna pick up new Delco plugs tomorrow, so I'll post back if it fixes it.

Is the 3.1 Plenum a straight swap? I wanna swap that and/or the bracket behind it so I can put the coils/icm in the location it is on the 3.1 Corsica's (directly behind the plenum) sometime in the future so it isn't such a pain to get to them when the time comes for them again.

And yeah, looking at the engine bay on my LeMans, you can tell it was laid out with so much more logic than the engine bay on the GTU was.

[3X00-Modified]

3.1's do not have the coils behind the plenum. The 3100 does and in that case no the intake is not a direct swap, they are completely different engine generations.

[GTU89]

3.1's do not have the coils behind the plenum. The 3100 does and in that case no the intake is not a direct swap, they are completely different engine generations.

There was a 3.1 (not 3100, I know the difference) Corsica at the junkyard with that setup, I can even snap a pic next time I'm at the junkyard.

[3X00-Modified]

Then it was done after the fact by someone... all the MPFI motors had the coils under the front exhaust manifold, it was only after the introduction of the 3100 that they moved them up top.

Just remember in doing this you may need to extend some wires to reach but it is a very common mod to eliminate some of the heat from the coils.

[GTU89]

Oh, okay, that's pretty cool someone cared enough to do that. So if I grabbed the wires and plenum and whatnot from the Corsica it should be a straight swap?

[Money pit Beretta]

It should be the same. The 3.1 has the same bore as a 2.8, just a little more stroke. You found one with coils on top? What year was that?

[GTU89]

It should be the same. The 3.1 has the same bore as a 2.8, just a little more stroke. You found one with coils on top? What year was that?

I'm thinking a 91+ because IIRC it had the 91+ interior. But yes, the coils were mounted on top, I oughta grab the stuff off of it to do the coil mounting swap before too long. The coils/ICM looked brand new on it too. Looked like someone gave it a tune up before junking it lmao.

There is also a mint condition purple Z (well, minus the front clip and engine) sitting there as well, weirdly enough the time before last I was there it had really nice Z seats, but now it has really nice burgudy 89 and older buckets, except some jackass rolled the windows down on it so the carpet is growing moss.

Cleaning the plugs right now since I can't get new plugs until tomorrow. Three of them are hideously coated with black crap, one or two of them are out of gap, and the others aren't looking to great either, and they only had a few hundred miles on them. Using brake fluid and carb cleaner with a tooth brush to clean them.

Three of them look more or less like the middle on in this pic I found on google: (not that style obviously, but the black crap)

[Money pit Beretta]

So what are the lower mounts on the 91? On the 95 the lowers have studs(that come off the head) and a spacer.
I only run AC's in my cars. I had a problems with other brands.
Yeah it looks like that one was a little rich. Must have been that bad seal.

[Money pit Beretta]

Dang man the shank on those look a bit long.

[GTU89]

Dang man the shank on those look a bit long.

Haha, not my pic. I got it off of google.

Well, I cleaned them, and it's still kinda rough, maybe a tiny bit better. The guts of my one plug wire ripped out and stuck to the plug, so I had to put a slightly longer original wire in its place. Think its still worth getting new Delco plugs tomorrow? I could only get them about as clean as the plug on the left in that pic.

Not sure, I was in a rush, but I know they were mounted there, just not the details of it. Looked factory though.

[3X00-Modified]

If they are that dark then you could have an injector failing... especially if three plugs were that dark, they could be missfiring and spraying extra fuel making one bank extra rich.

Bottom line, plugs aren't going to fix it... You need to check/replace the injectors or swap out the ICM. ICM will test fine at autozone because its not hot enough... remember that.

Pull the rear injector harness and check the ohms on the banks... see what you get.

[GTU89]

If they are that dark then you could have an injector failing... especially if three plugs were that dark, they could be missfiring and spraying extra fuel making one bank extra rich.

Bottom line, plugs aren't going to fix it... You need to check/replace the injectors or swap out the ICM. ICM will test fine at autozone because its not hot enough... remember that.

Pull the rear injector harness and check the ohms on the banks... see what you get.

This is right on startup, it's cold enough you can touch the manifold. Already replaced the regulator, icm and coils. I'll have to check the injectors then.

Keep in mind, it was running really rich for a while before it started acting really bad, so that is a few hundred miles of running rich, not that that is normal by any means, which I guess could mean that a injector has been failing. The regulator made it run almost normal (fuel wise) and the coils/icm really made it run much better, just the updated aformentioned problems. (which are mostly the same, just less extreme)

As I said though, I'll check the injectors.

Edit:
Damn, injectors are expensive, $58 a piece.

[Money pit Beretta]

You must have found an off brand, that is cheap. Most injectors cost more than that.

[GTU89]

Any chance that maybe driving it tomorrow (around a five minute commute each way) would make it give a CEL so I could possibly see what exactly the problem is? It seems almost like it's only missfiring on one cylinder now that I cleaned the plugs. I haven't really driven it at all since it started doing this.

Also, anyone care to elaborate on how to check the injector ohm's?

I can try to get a video of what it's doing tomorrow, that would probably help alot.