Great...now it's missing...

[RovinAround]

Ok.so I replaced my pass side ex manifold gaskets today. get her back together and now there is a miss...assuming 2 cyls as rough as she's running. I'm about to pull the plugs to see how they look...other than that..what's the best way to find the miss without having a OBDII scanner? 4.0 Gems

 

[HunterAK]

When was the last time you put new wires on and what wires do you have on there now?

 

[RovinAround]

2 wks ago. magnecor 8mm w/reccomended champion plugs.

Edit: gap .036

 

[RovinAround]

1,3 and 2 have a lot of carbon buildup for only being a couple wks old. 4 and 6 are fouled...think I found my miss(es)...
the rest seem to be burning fine...not alot of carbon...but some.

spark plug tester shows spark from coil pak to plugs 4&6....??? I'm getting beyond my knowledge here. If I have spark to the plug, then either the plugs are bad (does that ever happen?) or cylinder problems, right?

Thanks.

 

[RovinAround]

Ok...
While the truck was torn down, the wife was going to the store and hopped into the disco, started it up, and quickly realized I wasn't done with it when she heard it. Here's the deal..all plug wires were off on the pass side, and the exhaust manifold was also off...I can't believe the damned thing started at all...

this is what I get for going potty in the middle of a tear down...

besides an idiot wife...what am I now dealing with?
Thanks.

 

[RVRSRVC]

Um, have you verified that you haven't crossed two cylinder's worth of wires? Say, what are we working with here, anyway? D1? D2?

 

[RovinAround]

96 D1 4.0 Gems
Thanks. yes, I've verified the wires are correct.

 

[RovinAround]

Bump..any ideas? 4 & 6 are still fouling out plugs..

Run the engine for aminute and pull the plugs...they're not firing even though they're getting spark. I've swapped the plugs around, and the issue is still there.

 

[hondamnit]

where was the crack on the maifold and how bad of a crack was it ?

could it be that you have burnt valves on those two cyl's ?

i would OHM out the wires on those two cyl's then do a compression and cyl leak down test on all the cyl's

dont be scared that its something that major but its always nice to cover all the bases and rule out major trouble.

 

[RovinAround]

the manifold wasn't cracked. replaced due to shearing off a stud in the flange connecting to the downpipe.

Thanks!

 

[ptschram]

It ran fine until you tore it apart to put a manifold on it, right?

What else could have changed? Logically, the most likely issue is mis-routed plug wires, nothing else really makes sense as nothing else should have been disturbed.

Go back, retrace your steps (so to speak) and see what you did wrong.

 

[Chris-St Louis]

http://www.discoweb.org/forums/showpost.php?p=535069&postcount=5

 

[RovinAround]

PT..I just completed going over everything down to checking gaps, continuity testing wires, verifying wire locations with coil pack stampings and RAVE.

The truck was running fine, great really, prior to the teardown. There are really no sensors, vac, or the such in the area to have been disturbed. Just a simple pull the wires, unbolt the downpipe, unbolt the manifold, and refit. This hour job has turned into a PITA.

Edit..I've not yet done a compression test..that's planned for this evening...thanks for the infor Chris!

~Rovin

 

[singingcamel]

If it ran fine before then crappy after, its got to be something you did, and the easiiest mistake is the plug wires, but you checked them.
check the gap and compression or get hotter plugs or try different plugs

 

[RovinAround]

I know this makes no sense at all. I've swapped the affected plugs with the bosch's that I replaced last month (they were only a couple months old so I kept them for a pinch..) and gained the same result....

Coil sending spark
Wire carrying spark
Good plug doesn't seem to fire in the cyl.

I know the vehicle ran for probabally around 10-15 seconds without having that entire side firing... what damage could that have caused? ..if any... With it being a Gems, can we safely rule out timing since they are supposed to automatically calibrate that??

I'm picking up an OBDII scanner today while I'm out, so I' should have specific codes. Hopefully along with the compression test, we'll be able to narrow it down....

Thanks for all the input guys!
~Rovin

 

[Chris-St Louis]

You have Champions in there now though, right?

Opps, Reread your thread.

 

[RovinAround]

You have Champions in there now though, right?

Yes. I bought the ones listed on the RAVE...11CY's I think they are...I swapped out 4&6 hoping for bad champion plug...yea right.. same results.

Thanks.

 

[gmookher]

recently changed a exh manifold gasket as well, also had to work on a stud on said manifold to downpipe connection/gasket

its very easy to mix up the plug wires. I know you said you checked this, but if it ran good beofre pulling the manifold, the problem is likely in the plug or the wire(s)

I once got pretty confused with the firing order/coil pack diagram, and it took a few tries until i removed them ALL and started to redo it from scratch and then found my problem

also, if the hood is open, and tools are strewn about the work area and the work light is draped across the rig, she wont try to start it...

it IS possible valve damage occured if you/she ran it without an exh manifold.

 

[RovinAround]

also, if the hood is open, and tools are strewn about the work area and the work light is draped across the rig, she wont try to start it...

I have a habit of picking things up and lowering the hood...my kids are way to interested...which is great..but not when I'm not around!!

 

[RovinAround]

it IS possible valve damage occured if you/she ran it without an exh manifold.

I've always heard of people burning out their valves from lack of appropriate exhaust systems...but would that cause this mess?

Thanks,
Rovin