PING again. Tested Fuel pressure. Came out ok.

Hi all,

The Pinging problem continues. I tested the fuel pressure today and it comes out at or above what Hesco recommends:

Hesco = 30 psi at idle Mine = 31 -> 32 psi at idle

Hesco = 34 -> 38 when driving Mine = "Hose not long enough to stick out of the hood to see to test"

So I couldn't test when driving unless I take the hood off which I'm not opposed to doing I just didn't have time this evening.

So I'm at a loss what to do next. I was warming up to the Adjustable Fuel Pressure Regulator as a fix but if I'm in line with the pressure I'm suppose to have then doesn't that leave that one out?

Does this mean the 4.0L head is the only fix?

Agggghhhh :-(

Reply to
William Oliveri
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Try the carbon thing... spray water into the throat while running. You could have carbon buildup, causing high compression. __ Steve .

Reply to
Stephen Cowell

Hi Steve,

Did that already. Here's the list so far:

  1. Raised the Octane level to 91
  2. Changed plugs to cooler plugs per Hesco.
  3. Retarded the timing 6 degrees with a DRB II (JeepsRUs)
  4. Ran water through the intake manifold (a pint) to clear carbon.
  5. Tested fuel pressure.

You mentioned before regarding my spark plugs:

"Black on one side of the white cone indicates bad or brand new valve guide seals... "

Would this be a cause of ping?

I'm going to consult Hesco and JeepsRUs tomorrow to determine a course of action. Meanwhile I'm not driving the jeep as I don't want to do damage to the engine.

bill

Reply to
William Oliveri

Reply to
L.W.(ßill)

Reply to
L.W.(ßill)

Uhh.... in the list below #3,

Thanks though.

bill

Reply to
William Oliveri

I'll double-check with JeepsRUs and Hesco tomorrow on that figure.

Thanks,

Bill

Reply to
William Oliveri

No... ping is advanced timing, too much compression, or lean. You just put on an MPI... look for vacuum leaks, is all I can think. You've got a sticky one... maybe try mixing some av gas in? __ Steve .

Reply to
Stephen Cowell

Reply to
Will Honea

Thanks Steve,

What is av gas?

Reply to
William Oliveri

Reply to
L.W.(ßill)

Unless they've changed aviation fuel in the last couple years, then DO NOT run any through your Jeep unless you don't have a catalytic converter. They are not compatible with aviation fuel.

Chris

Reply to
c

Try octane booster, then... that's what I'm getting at. If it's a compression problem, then upping the octane will cause it to go away. __ Steve .

Reply to
Stephen Cowell

Yup, much better suggestion. AV gas messes up a converter in a hurry, and may also play havoc on an oxygen sensor. It sure was nice to use before the days of emissions though. I lived about 3 miles from a very small airport (only private planes now) during my early hot rodding years (I'm now about 8 blocks away from same airport). They still sell us AV gas if we want, but it's more expensive than the Turbo Blue racing fuel we can get.

Chris

Reply to
c

Reply to
L.W.(ßill)

When they had the DRB II on it, did they look at the sensor readings? Did the Baro reading make sense considering the elevation & conditions at your location? MAP sensor could cause this.

Anything that could cause a lean condition could cause it. Coolant temp sensor making the computer think it's hotter than it really is. An O2 sensor that's out of spec could make the computer think it's rich.

All the sensors have to work properly for the computer to correctly determine out how much air it's taking in, and how dense that air is.

Reply to
bllsht

This I can't tell you. I only know JeepsRUs have extensive experience in this matter so I have to trust them. I don't (yet) have a DRB II of my own to view these settings myself.

One thing JeepsRUs have suggested as the next step is one of those Tornado things which the owner of JeepsRUs was surprised worked on another jeep to relieve the pinging. If it works and is a simple fix I'm all for it. I'd rather be driving my jeep at this point than tearing it apart to put the

4.0L head on it.

bill

Oliveri"

Reply to
William Oliveri

With higher fuel pressures and better electronics, the PCM handles all that now.

Reply to
bllsht

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