Swapped in a known good AFM, no fix there. Took it off a running TII. Put it back on the donor TII and it drove away just fine.

At this point, I am convinced I am looking at the mother of all vacuum leaks, but for some reason the source eludes me. The fact that I can spray carb cleaner in the area of the LIM/Oil injectors leads me to believe this is so at this point. But I am always listening to new ideas!

Tomorrow I am breaking the entire top half down and replacing all the vac lines. I have done it before, so doing it again wont be an issue. Taking off the LIM presents some problems as it is an ABS equipped car, and I havent owned one before. Should be fun!

Rat

 

Hmm, a tough one this problem is.

Keep fighting!

 

1) crossed leading plug wires? (yes even i get em mixed up now and then and the car will actually run alright, not great but alright)
2) did you check the injector clips at the primaries? could be one is getting contact ever so slightly to run OK at higher RPMs
3) do an injector-on-rail test while you have it off this time to verify #2) is not the case and that the injector cleaning was done right and to verify the integrity of the wires from the injector to the ECU
4) possible still another large vacuum leak in the system such as cracked brake booster hose, multiple vacuum lines cracked and leaking or as you said a cracked LIM--->block gasket

i am tracing out a leaky brake booster in my car currently, vacuum drops to 10 intermittently and up to 16 at idle again at times, a noticable 3+"Hg drop in vacuum can be noticed at times when touching the brake pedal so i wouldn't rule out the booster itself as a possible cause either though they rarely fail.

good luck

 

Sounds like your best option si to pull the entire intake assembly, and replace all gasket, vac lines and remove anything that isnt necessary to the operation of the car.

For $700 for a TII the cost will still make it a seriously good find.


BC

 

No, but it wouldn't help.

 

my only ? is why the **** was this perfectly working TII in the junk yard

 

because it probably had a small problem and no mechanics would touch the magical rotary engine..

if you look hard enough you can find good FCs that people are just giving away, i picked up one and he actually tried to dump another on me and a few months earlier i was offered a free TII that had a PD fire but space is an issue, i'm not running an FC wrecking yard or resto shop.

i gotta be choosey about which cars i accept for free.

 

Man on my TII the LIM Gasket was crap and mine would idle at like 1000 rpms and very crappy replaced it and now Idles smooth. It is kinda a pain to pull the lim on a tII because you have to remove the turbo also but its not that big of a deal...

Also I kinda feel ya taking the UIM off over and over, but mines easy,(rats nest removed, TB Mod, I run premix also, so not so much crap..

Hope to see it running smooth, good LUck!!!!

 

That's what it's starting to sound like...LIM gasket.
Can you get one of those thin tubes on the carb cleaner spray can and pinpoint the leak a little better?
Spray very sparingly to see if you can get it narrowed down further...


-Ted

 

Oh, you are going to love this...

1) No, thats been checked and rechecked, although I fail to see how crossing the leadings would do anything, the leading plugs fire together.

2) Both primary injector clips are BRAND NEW.. I replaced them all!

3) I can do an injector on rail test, although I do trust the guy that cleans my injectors I suppose the test couldnt hurt since I have to pull it all back up anyways.

Dude, you have no idea how many cars I can get my hands on.. I had to stop working yesterday to go look at an S4 N/A in PERFECT shape that someone wants to sell me for $500. Its seriously BAD here in Tucson and I am basically the only game in town. But like Karack, I am out of space. I work at home and I already have 3 FCs and a 4th one coming this weekend!

Thats true, and its on my list of things to check. Sorry if my post seemed a bit bitchy, it wasnt meant that way.


Well, believe it or not thats good news to hear. I am not afraid to pull that entire motor apart, I just didnt want to do unneeded work. I would like to pull all that emissions stuff off but the Mrs. J-Rat wants a stock TII, as in BONE STOCK. So I am trying not to do anything that will detract from this.


I was using a thin tube, and it seemed that no matter where I sprayed under the UIM, the idle ran up. Then I got some Vac line and attached it to my thin tube and tried to narrow it down even further, but after a while I couldnt see anymore because my eyes were burning, so I had to stop for the night. Maybe I should move the car out of the garage before I start spraying massive amounts of carb cleaner?

So the plan now is to remove the UIM and the rats nest and replace/zip tie EVERY SINGLE VACUUM LINE on this car (done this before, aint afraid), then re-install and test again. If this doesnt work, then the LIM will come off, and that gasket will be replaced.

Remember, this is in the interest of science!

 

Wow, the pickings are kind of slim here. Not to mention you probably don't have to worry about rust.

 

Well, the main point of this thread was to systematically eliminate causes of the crappy idle in order to assist others in the future. So naturally I am chipping away at the possibilities one at a time and reporting the results. However, I eliminated what I percieved to be the "obvious" problems first (clean injectors, AFM, wiring, etc...).

 

When you did the injector O-rings (primaries)......did you pull out the little plastic bung dealies and diffusers out with a pick and try fresh O-rings on them also? Or just the injector seat o-ring?

I've had those little bastards cause some idle issues before...but it was more of a minor hunting issue than a high idle. Nontheless, something you may want to think about if you have the UIM off for the 60th time.

 

Another good suggestion! However, I did in fact pull up the diffusers to ensure they were clean (they were not, so I cleaned them). Also, the o-rings on the base of the injectors are all brand new and seated correctly.

Rat

 

if you can get in there, may as well try tightening down the LIM bolts if you aren't planning on ripping it off just yet, could be that they have worked their way out some and causing a decent leak.

 

Everything is off..

The vac spider was kind of toast... I am in the process of replacing all the vacuum lines.

I want to take off the LIM soo bad.. Did I mention this is an ABS car?

Ugh.. Decisions....

 

Yo Rat, just pull everything and strip that bitch! There's no point in beating around the bush and wasting your time trouble-shooting a stock 20 year-old engine bay... Pull everything that doesn't need to be there, block everything off and get the show on the road! Either way, I vote for a bad seal on the injectors.

~Erik

 

Where is the fun in that!!??!!

 

Has the turbo been pulled on this car before? As in does it still have the stock heat shields? If not its easy to pull the turbo then the LIM is a sinch... Hell i bet I could pull the UIM and the turbo in an hour... but yeah my LIM gasket was toast the thing that made me go ahead and pull it was that i had the UIM off and i pull a big chunk of the LIM gasket out that was kinda just sticking out hahah... so mine was obvious.... but good luck man!!!!

 

Have you looked at the manifolds to make sure they're in good shape? My 87 TII was having high idle problems, couldn't get it go go below 1200 rpms. Turns out the LIM is cracked in the corner. I replaced it with another LIM and the idle problem was fixed.

 

dude... if i was you.. id just throw that bitch away. put it back in a junk yard..

did i mention that i run a wrecking company? pm me and ill give you a free tow to the yard for being a fellow enthusiast.

gotta know when to throw in the towel..

and i vote lim, ive had a similar problem with a lim

 

Sorry, failure is not an option. And since between me and the Mrs. we have 3 other running vehicles, I have ALL the time in the world to figure this out. I do happen to think the LIM gasket theorists are right. However I dont have a gasket (its on order) so this leaves me at some form of quandary. I can either put it all back together again with all fresh vac lines/etc and see if it works OR I can continue ripping it down and prepping it for a new LIM gasket...

 

well the LIM gasket does crack occasionally but it isn't all too common, some people seem to think just because it is missing some chunks it wasn't sealing which isn't necessarily the case.

 

So I take it your vote is to put it back together?

 

if it was me i would do what i suggested last night just fix the vacuum lines and throw it all back together and see what happens, the LIM is a bitch to replace on a 100% stock TII especially with ABS so i would only go there if it still isn't cured after the vac lines, carb treatment and some run in time.