Renix Dead Spot And Idiling Low

[1989 Eliminator]

So ive done quite a bit of research before posting this and ive found similar idle issues.

 

Mine mostly idles low like ~500 and bounces around. It goes lower than 500 sometimes then catches itself and idles back up a little. Sometimes its just a constant low idle. I also feel and hear a miss when idling. Small vibrations which is when the idle drops.

 

Also if i quickly "brap" the throttle there is a dead spot, then it revs up a bit, but when the rpms fall, the engine wants to stall but catches itself.

 

Once i get going cruising, WOT, the engine runs fine.

 

I replaced the TPS because I thought that was it. i tested it before and was okay but with my research everyone was saying TPS or IAC.

 

I have no vacuum leaks. New intake gasket, bolts are tight, no exhaust leaks, replaced all the hard vacuum lines with rubber ones. New spark plugs, copper champions.

 

I do not wanna spend money on sensors i don't need. Any ideas?

[1989 Eliminator]

Any thoughts on this?

 

http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/1193383/1

[neohic]

Been keeping an eye on this with high hopes. Mine occasionally does this as well.  :popcorn:

[1989 Eliminator]

Like other than that it runs awesome. I am going to clean my ccv and try to make my valve cover not leak oil anymore..... :crossfingers:

I know there are a lot of threads on low idle and such but each one just isnt the exact same issue. Or the solution in the other threads I have already fixed.

[Strokermjcomanche]

I'd do Cruisers renix tips first . Atleast you can eliminate other potential problems and it doesn't cost anything but some time .

[1989 Eliminator]

Yeah trust me I have. Ive done most of them besides the ccv fix which I'm doing wednesday to see what that does. Becasue I am getting a little bit of oil in my air filter.

[cruiser54]

Could be your O2 sensor dying. Unplug the sensor and use an ohmmeter between the red and black wires of the sensor plug. Should have 6 to 8 ohms. 

[1989 Eliminator]

Bump. Still having this low idle/ dead spot. I just bought a new O2 sensor and it didnt change anything really. Still idles low. The O2 sensor I bought is a BOSCH.

[cruiser54]

Check your distributor indexing. Post 13.

[1989 Eliminator]

I will cut my old distributor cap at cyl #1 and put cyl #1 at TDC to see where the rotor ends up at. But do I have to cut the ears off of the locatiing tab in order to turn or move the distributor into the correct position?

[1989 Eliminator]

Plus I do not see why the alignment of the distributor would be bad since i never took it out or messed with it.

[cruiser54]

Plus I do not see why the alignment of the distributor would be bad since i never took it out or messed with it.

Process of elimination. Things wear.

 

Yes, tabs must be removed. What about this? What if somebody already performed the indexing as it was a factory fix, and it has somehow moved? 

[Comanchemodder]

Does it happen only when your low on fuel, say 1/4 tank or less?  When you have a full tank, it runs fine?

[1989 Eliminator]

No it happens all the time. I'm going to index my distributor just to check that.

[oldseddie]

I have fought a dead spot just off idle since I got my 87 Chief and this is what fixed it. Took 30 min. I marked the #1 post on the dist. and then removed the cap and turned the crank with a breaker bar till the ballancer mark lines up with TDC mark and rotor pointed to my #1 mark. I then swapped out the cap for my windowed one and it was off several degrees. Just follow cruisers tips.

[cruiser54]

Eddie, thanks for the encouraging words. I automatically do the indexing on any Renix Jeep I work on. Definitely worthwhile. 

[91Pioneer]

What if your brand new harmonic balancer doesn't have a mark on it? I don't remember seeing one on the Dorman one I just installed.

[gogmorgo]

The Dorman (594-018) I put on back in February has this notch in the lip closest to the block:

 

 

I'm assuming it's a timing mark, although I didn't check to see if it lined up with the one I pulled off at all, and I don't has dat one no more. 

You might be able to see it when it's oriented to line up with the timing marks, but I don't know. As far as my fingers can tell, it doesn't extend any further onto the pulley, it's just that little notch on the back, but I didn't bother popping the hood to look from above. My apologies for the potato picture. My phone's all I've got as a camera right now.

[cruiser54]

What if your brand new harmonic balancer doesn't have a mark on it? I don't remember seeing one on the Dorman one I just installed.

It does.

[1989 Eliminator]

My harmonic balancer is not new and actully the rubber seal or bushing for the balancer is partly sticking out like it is going bad.

 

But i indexed my distributor. And here is the result. The black mark on the right is the centerline for cyl #1 post. The mark on the left is the estimated position of where the rotor should be. The rotor edge of the arc should just be past the cyl #1 post. Which it is.

 

[cruiser54]

Actually, it should be .020" PAST the dizzy cap terminal. That's why you need to use an old cap that's been cut up. Way more accurate. Oldseddie's was not far off and he had issues with it....Just sayin...

[1989 Eliminator]

Okay I'm at school right now so i don't have my old one on me. Ill make the window hopefully this weekend

[cruiser54]

Okay I'm at school right now so i don't have my old one on me. Ill make the window hopefully this weekend

Good. Much more accurate. Keep us posted please. 

[91Pioneer]

Thanks folks I will have to look closer to see if I have that mark, I assume there is only one Dorman balancer to fit the 4.0. Not that I'm having the O/P's problem, so I'll stay out now.

[1989 Eliminator]

Okay so i took the cap off and the rotor has a little play in it. Like i can kinda turn it back and forth a little. Is that bad?

 

Also, sure after cutting the locating tab off you can turn the distributor but the cap and rotor and distributor are all bolted together so they all turn equally.