Poll: What is causing my idle stumble?

[85_600]

As the poll says...

I already replaced my Speed Sensor, no change. Here are the symptoms:

Idle, in PARK, is fine, no problem. Idle in gear ( Reverse or the others ) BUT, not moving, fine, no problem.

However, in gear, any gear, when I first start to move I have a "slight" stumble then I go. It's VERY slight but I thought I better include it here.

It's mainly when I'm driving at slow(er) speeds, like around residential streets or, the worst, parking lots, in particular, parking garages.

Driving straight, in any of the above situations, coming to a stop, the idle is sort of ok. There is a drop in rpms but it doesn't make the car stall.

Now, the same situations above BUT, turning OR going up a slight hill ( like in a parking garage ), whenever there is a load on the engine, it wants to stall but about 98% of the time it catches itself. If it's bad enough to where the whole car is shaking BEFORE it catches itself, I hear a relay type of "click" from under the hood, drivers side, then, when it's back to normal, it's fine on the idle.

What really gets it doing the stumble is turning AND going up a slight hill, which I do daily when leaving work.

So, here are my options:

AIS
TPS
MAP
All 3
None of the above ( If this is selected, post up your answer please )

Thanks for the help! I certainly needed it and GOT IT for my SDS replacement.
Paul

**EDIT**
I have checked for codes, as a matter of fact, I check them almost daily, and all i have is 55 - All Clear.
Also, the car, even though it's 21 years old, only has 45k miles on it.

[5sp. mini]

dude you need to run a scanner on it . it maybe a lean miss or out of time . not norm. but crank and cam. fuel presser test?AL

[85_600]

dude you need to run a scanner on it . it maybe a lean miss or out of time . not norm. but crank and cam. fuel presser test?AL

Back around November 14th / 15th I had the car in the shop. I was going to replace the O2 myself but someone rounded the old one off so i had the shop install the one I bought. While it was in there I asked them to check a few things over, including the timing and such. Everything got the A-Ok.

It hasn't gotten any worse in the almost 2 months I've had it. Actually, it does get a "little" worse when it's warmer out. When it's really cold it stays running no matter what, if that helps.

[jre97]

Check your codes and fuel pressure. Could be that the fuel pump is trying to die or you could have clogged or bad fuel injectors.The off the shelf injector cleaner doesn't work if you have clogged injectors, may be ok for preventative maintanence. Check your fuel filter. Check your timing.

[85_600]

I just added to the main post - I check for codes almost daily and the only one I have is 55 - All Clear. I also added that the 600, even though it's 21 years old, it only has 45k miles on it

Thanks for the fuel ideas. Would this cause the symptoms though? The only reason I ask is due to that relay type of click I hear when the car is "just about to stall" then catches itself. ( I say 'relay" type of click because it sounds the same way the fan relay does when it kicks on )
Also, I was thinking 'electrical' due to the fact that I don't have any codes. That's the main reason why I did the SDS repair. According to Mini Mopar the SDS, when being funky, doesn't throw a code.

I can likely try the filter fix but the pump may be a bit beyond my means as of now. I don't have daily access to a dry environment

[85_600]

Check your codes and fuel pressure. Could be that the fuel pump is trying to die or you could have clogged or bad fuel injectors.The off the shelf injector cleaner doesn't work if you have clogged injectors, may be ok for preventative maintanence. Check your fuel filter. Check your timing.

Is there a "off the shelf" injector cleaner, of sorts, that does work?

[Blue Iroc R/T]

Is there a "off the shelf" injector cleaner, of sorts, that does work?

Paul,
I can't think of anything that you haven't already tried, except I would bump the timing to 14* to see if that helps it. As far as Fuel Injector Cleaner, I put a can of "Justice Brothers" in the tank of every car about every 6 months. I get it at the NAPA store right here by my house. Get off I-76 at Wooster Rd North (Exit 17), make a right (towards Barbeton), there is a Blue building on your right in the first block after you turn onto Wooster Rd., That's NAPA. I think it is about $6-$8 a can. When you pull into their parking lot, look straight ahead and you will see a long white garage about 4 house directly behind the store. That's my garage.
http://www.pbase.com/rmscott/image/40553755

[85_600]

Paul,
I can't think of anything that you haven't already tried, except I would bump the timing to 14* to see if that helps it. As far as Fuel Injector Cleaner, I put a can of "Justice Brothers" in the tank of every car about every 6 months. I get it at the NAPA store right here by my house. Get off I-76 at Wooster Rd North (Exit 17), make a right (towards Barbeton), there is a Blue building on your right in the first block after you turn onto Wooster Rd., That's NAPA. I think it is about $6-$8 a can. When you pull into their parking lot, look straight ahead and you will see a long white garage about 4 house directly behind the store. That's my garage.
http://www.pbase.com/rmscott/image/40553755

Thanks Ralph! I've got a Napa within walking distance here. I'll call them to see if they carry it and if not then I'll check your out.

The only thing(s) I have not tried are listed in the poll. I can get a GOOD working AIS / TPS together for about $20. I'd like to leave the MAP for last since I'm 'considering' a Stage 1 from FWD, which includes a new MAP. Why buy a MAP for $89 ( or somewhere around that ) when I can buy a Stage 1 for $100!

The ideas I can try so far are: Fuel Filter, AIS/TPS. That's the least expensive and sort of the easiest to R&R, at least for me. I'll try them out soon. I'm putting in some major OT Wed and Thurs so I may not have any results posted until next week.

BTW - @Ralph: I'd like to see this pic in REAL Life:

http://www.pbase.com/rmscott/image/40553995

[MiniMopar]

It's not the AIS. My guess would be TPS or perhaps a vacuum leak somewhere cause a lean condition right off idle. Check the vacuum lines for cracks, particularly the MAP and FPR lines.

My Datyona did this. It was a vacuum leak (actually several very small ones).

[GLHSKEN]

I'm with Russ... TPS or leaks..

[Subliminal]

Another thing to check would be to make sure the plug is all nice and tight on the injector harness area, and that the ground from the intake to firewall is good. My car does that clicking thing real bad if the injector harness is unplugged.

d

[Turbo Joe]

when the car is in motion is what makes it parquliar. makes me wanna check the dizzy cap and make sure it's dry inside.If it's full of water or oil and it sloshes around it would cause temperary problems. not a bad idea to check the airbox too but a clogged fuel filter will do it also. Basically, do the routine
checks before ya throw parts at it.

[PTT]

I'd also check the distributor vanes for looseness............

[3Bar_Mopar]

This may sound stupid, but may be something to check anyway....

I fixed a couple vac leaks on my car and then had a similar situation with the idle.... I reset the computer by dosconnecting the battery and everything was fine.

It does sound like a vacuum leak though..

[sdac guy]

I'd also check the distributor vanes for looseness............

I haven't seen this mentioned in some time (years) but it used to be a commonly reported problem and does affect cars mostly when in motion (g-forces at work).

In the distributor, below the HEP plate is the rotating vane assembly. The metal vanes are only heat staked in place to the plastic piece that they are mounted to. Over time, the staking of the plastic deteriorates and the vanes get loose on the plastic mounting. Once the vanes start wobbling around the engine will run poorly as it changes both ignition and injector timing pulses.

This doesn't necessarily sound like the cause of the problem you are having, but it is easy and cheap to check (and fix), and should be checked on any car that is having engine miss or roughness.

If the vanes are loose, two things can be done to fix. A rebuilt distributor can be installed (they used to be reasonably priced at the dealer and included a new HEP) or the vanes can be re-secured to the plastic mount.

Drill a hole in the center of the area of the old heat staking and use very small sheet metal screws to secure the vanes to the base. Be sure to use very short screws so they will not interfere with the rotation of the dist assy.

Some folks have used epoxy or silicone adhesive also, but if there is any grease or grime in there, it may affect how well the adhesives hold.

(but my guess in your instance, also is for the vacuum leaks).

Barry

[turbovanman²]

Barry, the car is gone, the fix is a new engine, he had bad compression in 1 or 2 cylinders and he got rid of it.