Topic: Some engine issues- Need help

[jfrabat]

I threw back in a stock coil and my Problems went away.  It was not rated at the right Ohms for the stock ignition system.

I believe you; I have gone through 2 screaming demon coils and one accel, plus two cheap ones...

[Torch_Ind]

I believe you; I have gone through 2 screaming demon coils and one accel, plus two cheap ones...

I had lots of issues with the stock style replacement coils. what I found was the problem was the connection style of the plug. would always cause coil failure.

I went to the old style coil with bolt on connections and haven't had any issues since

only prob I had was the connection end of the coil for the spark plug wire was opposite as the stock style one but the parts guys had cables to go to that style coil

http://store.prestoliteperformance.com/accel/accel-coils-accessories/superstock-high-vibration-coil.html

[jfrabat]

Guys, just to check (so I don't screw up when I do the test), the process is as follows, right?

• Run engine until it warms up
• Remove all 4 plugs
• Unplug the coil (connector coming from the ECU, not the one going to the distributor)
• Pull the relay for the fuel pump
• Hold the throttle body wide open
• Connect the compression tester (start at 1 and move to 4) for DRY test
• Squirt a bit of engine oil into each cylinder before redoing the test for WET figures
• Reinstall new plugs (might as well change them, right?), connect cables, connect coil, reinstall fuel pump relay, remove whatever I used to hold the TB open, and restart engine to be sure I did not leave anything disconnected
• Compare results (all cylinders should be within 10% of each other more or less)
• Post results here so that everyone can have a stab at how poorly my engine runs! 

If I get any significant differences, I may run a leakage test, since I already got the tester... 

Anyway, if someone can confirm the process, I think I'll give this test a shot on Saturday...

Felipe

[aw12345]

When you do a leak down test make sure to disconnect all the crank case ventilation hoses. Other than that to check engine mechanical condition a leak down tester is a much better tool to use than a compression tester. Just a bit more work

[jfrabat]

When you do a leak down test make sure to disconnect all the crank case ventilation hoses. Other than that to check engine mechanical condition a leak down tester is a much better tool to use than a compression tester. Just a bit more work

Which one is that?  the one that goes back to the filter box?

[sharpxmen]

it will vent to the filter, i doubt you need to disconnect the hoses, there's no check valve at the valve cover.

your plan looks good.

[jfrabat]

OK, guys, I'm stuck!  I took the jeep for a morning drive (minus the top) with the family, and it was running fine.  I then got it into the garage to do the compression test, and got all plugs out (they looked fine; I'll post pics later on).  For some reason (and yes, the thread is the correct size; it is not that!), I could not catch the threads of the plug holes with the compression tester on any of the cylinders.  I really dont get why I cant do this!  Anyway, while thinking about it, I took a look at the TB, and it was FILLED with gunk (pics of that also coming up), so I took it apart to clean it.  This is when I noticed that my TPS was cracked (and I accidentally finished the job of killing it - yet more of the pics loading up as I write).  Perhaps this is what was acting up, don't know...  So anyway, I cleaned it up, but now I need to buy a new TPS on Monday (IF I can find one locally!).  For now, the Jeep is sitting in the garage with no TB or plugs, as I still want to do the compression test just to see what it turns out...  I just put a rag over the TB opening, and another over the plug holes.  I may even take the oportunity to enlarge the intake manifold opening, but that kind of scared me a bit!

[jfrabat]

Here's how the plugs looked when I pulled them (Cyl #1 is on the left; there is some faint dust one the #1 and #2 cylinders, which are the ones my dad described as having "mud" last time he pulled the plugs):



By the way, I am using Champion RC12LYC plugs; can you guys confirm if these are the right plugs?  According to the Bosch book, these are a bit too cold (the comparable Bosch plug is, anyway) and Bosch recommended one step hotter for the Jeep...

Here's how the TB looked when I took it off:



Had gunk both inside:





and outside...



so I cleaned it and it ended up looking like this:





Unfortunately, I killed my TPS in the process (not sure, but I THINK it was already cracked, as it broke off WAY too easily):



Still trying to figure out why the compression tester will not catch the threads on the plug holes...

Felipe

[sharpxmen]

what's the hex size on the compression tester fitting, that migt bottom out in the plug holes before getting to the thread, there is usually an extender you can use in that case.



1 & 2 look normal, not sure why 3 & 4 have nothing on, were they wet?

[jfrabat]

what's the hex size on the compression tester fitting, that migt bottom out in the plug holes before getting to the thread, there is usually an extender you can use in that case.



1 & 2 look normal, not sure why 3 & 4 have nothing on, were they wet?

No extender on this one; I think it may be the angle, but I'll give it another shot tomorrow...  I'm too lazy to do a leak down test (TDC is kind of a pain to do 4 times...).  #3 and #4 were not wet...

[sharpxmen]

can you take a picture of the compression tester fitting.
you could be right about the angle

[grumpygy]

Just as plugs come in different Sizes so do the Compression testers.  I would bet the tester is for larger plugs than you are using.  were there any adapters with the tester.

[jfrabat]

Just as plugs come in different Sizes so do the Compression testers.  I would bet the tester is for larger plugs than you are using.  were there any adapters with the tester.

For some reason (and yes, the thread is the correct size; it is not that!), I could not catch the threads of the plug holes with the compression tester on any of the cylinders.

Thanks, Grumpy, but that is not the cause...

can you take a picture of the compression tester fitting.
you could be right about the angle

The problem is I got NO visibility in there to see what's going on when I put the tester hose in there...  Even in Cyl #3, which is the one I can look at the better, I cannot see what's going on!

[grumpygy]

http://compression-tester-extension.salehugedeal.com/

[jfrabat]

http://compression-tester-extension.salehugedeal.com/

That's more like what I need...  I have been trying to figure out how to use the leak down tester's hose for the compression test, but I cant figure out how to install a valve on that one...