Solving mysterious miss in 92' MTX (testing injector connectors)

[Phoenix]

thanks for making "burnt" and "bent" my first two options phoenix, that's just brightens my day :angelnot:

All I'm going to do about it right now is whine. I don't have any tools for valve work and I'm out of money now.. I am taking the valve cover off AFTER I fix the issue with the injector harness.

And I'm pretty certain the low voltage is the primary issue here. I'm going to test the wire as close to the CCRM and it I get 12v that tells me it's in the harness/splice somewhere. I'm going to find a point past the splice to test and it I get 12v there I know it's in the splice.

If I can't find the splice, lets be real here, there are a lot of harness going every which direction in the engine bay, I'm going to run a whole 12v supply of my own.

On the flip side, if I discover the valve is a " relatively easy" fix, would anyone be willing to lend me tools in good faith?

If you're out of options for now , pull the cover first , in the best case scenario you might have an ejected/stuck shim. If you see nothing , then you will need to pull the head out. But like Bob said , REALLY double check your results on number 2 , with oil and what not, before pulling the head. Just to be sure you are not gonna do all that work for nothing.

 

[trainguy1989]

I had a SHO engine that had no compression on all the cylinders. I put a little ATF in each cylinder and she fired right up. I must of washed all the oil off the walls with gas or had sticky rings. To this day she starts every time. I would do what Bob suggested and see if anything changes when adding a little oil to cylinder #2.

 

[kevinspann]

If it spit a shim, wouldn't that valve stay closed, and that cylinder would show compression?

 

[vortex2450]

Okay, how much oil are we talking here? A teaspoon sized amount?

trainguy, I'm no expert here but it's only cyl # 2, I'm going to try it again with the oil in the there , right now I'm kinda of grounded because of the weather, I'm watching the radar for it to clear up some.

and Kevinspann, you tell me, I dont' have the first clue, I don't even know what the purpose of the shims are, but I'm gonna go hunt those answers down.

If the problem is damage to the valve itself what are my options guys?
Do i have to buy a whole new set? Or can I simply find a used valve in good shape somewhere? I don't know that's why I'm asking.

also, I tested the red wire out at the CCRM, It's got 12v, I'm waiting for weather to lighten up before I chase down the splice.

 

[kevinspann]

A teaspoon should work.

If you have to replace a valve, you'd possibly be better off looking for another cylinder head, since the you have could be damaged. It's easier/possibly cheaper than getting the head redone....if that's the issue.

 

[Phoenix]

Okay, how much oil are we talking here? A teaspoon sized amount?

trainguy, I'm no expert here but it's only cyl # 2, I'm going to try it again with the oil in the there , right now I'm kinda of grounded because of the weather, I'm watching the radar for it to clear up some.

and Kevinspann, you tell me, I dont' have the first clue, I don't even know what the purpose of the shims are, but I'm gonna go hunt those answers down.

If the problem is damage to the valve itself what are my options guys?
Do i have to buy a whole new set? Or can I simply find a used valve in good shape somewhere? I don't know that's why I'm asking.

also, I tested the red wire out at the CCRM, It's got 12v, I'm waiting for weather to lighten up before I chase down the splice.

More then a tea spoon , If it was me , I would put more like 6-7 to make sure the piston is covered.

And for your engine interogations , im gonna send you a little e-book about this engine , you might wanna read this in your spare time , its explains everything about the sho.

 

[vortex2450]

Thanks, for that. I can't pull the intake and VC off right now due to weather (some sort of hail/snow mix). AND thanks a billion phoenix, that's the kinda of resource I need.

I[ B] have[/B] isolated the source of the voltage problem,


I took some pics for you guys:



These two connectors (in red) go into the injector harness. The blue circle is a massive 5 way intersection where the problem probably is.

Note the electrical tape on the black connector.... It looks darker and newer then the rest of the harness, it this possibly the evidence of someone's (not so) handy work ?


Here's the red wire in question,



And then pin itself, which after two checks read out 3.56v



Now seeing the newer and not so factory looking wrap on the black connector I'm guessing somewhere along the way someone was inside that harness and botched something somewhere eventually leading to the sudden short and hence forth a multitude of the injectors simply stop opening/closing.

As frustrating as this all is I'm starting to feel a glimmer of satisfaction in pinning down this elusive problem.

 

[vortex2450]

After already starting to wire a new wire to the red wire on the black connector I realized that it was actually red w/ a black stripe. So out of blind luck turns out the splice was pretty darn close to the CCRM.

It's a three way splice, so what is the 3rd wire going to??

I haven't checked the wires after the splice for voltage yet, I spent a frustratingly long time fighting a rusty clamp that impeding me from taking the thermostat housing off (to allow easy access to the harness).

Clamp in question...


Tomorrow is day #5. Hoping to get some sound results...

 

[vortex2450]

Update guys.

Yesterday, after I ran a new 12v wire to the 5thpin on the black connector I tried firing it up with no success, today as I was beginning to remove the intake I noticed i never plugged the DIS back in from compression testing.

I got it running again, for split second it's fine but every time cyl #2 fires it's horrible. overall the sound of the engine is improved but it still has the same miss, it sounds like the engine is literally dieing though...

I'm beginning to think way back to when 93rev said the car spit a shim he was right and I believe that may of been a side effect, I'm going to email the PO to ask about it..

I pulled the spark plug from the cylinder in question AND gray smokes was pouring out, the plug was covered in fuel (old gas without a doubt but still gas).

I poured a liberal amount SAE-40 into the cylinder and I'm giving it a chance to settled in there before I try compression again. I would prefer my go to oil but my little brother robbed my extra Quarts of Mobil-1 for his go kart

Does the fact the I had gray smoke coming from the spark plug well with the plug removed say tell us anything?

I'm going to go run a compression soon, I'll be back with results...

EDIT: No compression still.

I took some vids before I rip off the intake and VC off to document where it's at now. Definitely a difference from where I started. But not ready to run :\

When the videos are uploaded I'll post the links. I hope someone is still following with me here

Videos of the car running with the miss:

From the Outside:
http://s757.photobucket.com/albums/xx220/vortex2450/?action=view&current=100_2863.mp4

From the driver's seat:
http://s757.photobucket.com/albums/xx220/vortex2450/?action=view&current=100_2864.mp4

At the exhaust:
http://s757.photobucket.com/albums/xx220/vortex2450/?action=view&current=100_2866.mp4

 

[luigisho]

We're still following. Nothing to be done until you start ripping it open. It runs and has a dead cylinder. Waiting for valve and piston/ring info.

 

[vortex2450]

I'm at the valve cover now, any suggestion for loosening the cover bolts? They are pretty tight, are they reversed threaded or should I just put some real muscle into it?

I truly cannot get any of the hex bolts to budge, I know there's a trick but I'm clueless as to what it is, someone want to help me out?

 

[Phoenix]

I'm at the valve cover now, any suggestion for loosening the cover bolts? They are pretty tight, are they reversed threaded or should I just put some real muscle into it?

I truly cannot get any of the hex bolts to budge, I know there's a trick but I'm clueless as to what it is, someone want to help me out?

These bolts have nothing fancy to them , put your back into it.

But make sure your allen socket (I hope you're not using just an allen key) that is super tight in the hole , if not you will have bigger problems.

I have also used Torx male sockets with success in the past if you dont have the right tools. Again make sure its tight.

 

[luigisho]

These strip and snap easily. Use alot of muscle and try not to get sloppy and mess up the allen slot at the top of the bolt.

 

[vortex2450]

Does a 5mm Allen sound right? Problem is I don't have an adapter to attach the allen to the 3/8" ratchet, all I got is some cheesy ratcheting nut driver...

 

[SHOspazz92]

Just be CAREFUL and do not use any more force then necessary. Make sure the allen wrench is seated well in to the bolt. ESPECIALLY when you are putting them back in.

-Sam

 

[Phoenix]

Does a 5mm Allen sound right? Problem is I don't have an adapter to attach the allen to the 3/8" ratchet, all I got is some cheesy ratcheting nut driver...

Then you might want to borrow the right tools , dont rush this to a point that you strip one, then you will be sorry that you didnt waited. By stripping I mean the hole , not the threads.

 

[luigisho]

I forget if it's 5 or 5.5. Been a long time since I had my GenI. I did manage to strip the hole and break a bolt or two first time with the valve covers. A big job on the back head where I sheared the bolt in the hole. Just make sure it fits correctly without extra room in the slot. Very easy to round the hole off.

 

[vortex2450]

I hear you loud and clear, I almost slipped up and stripped one, I just taped off the exposed intake holes, put a towel over the engine, and closed the hood for now.

tomorrow I'm going to stop by a friends and see if he has 5 and 5.5 mm allen on a 3/8" drive socket.

Besides, knowing the exact problem with the valve doesn't help me much at this point with literally all my cash tied up.

At least I'm close..

 

[Bob Gervais]

It's a 5mm. When you do put the socket in the hole, tap it in with a hammer just to make sure it's seated well.

 

[93rev2sev]

Constant steady pressure on the wrench is the key to NOT stripping out the hex holes.

I've held the same amount of torque on one bolt for over 30 seconds fearing that if I put any more torque on the wrench it would strip the hole. Eventually, it popped loose.

I've had more than one stubborn bolt strip out with very little effort. I had to cut a slot into it so that I could use a large flathead screwdriver...two screwdrivers, actually; one on each side of the hex hole.