Head Gasket Problems

[Reza Taheri]

 

4 hours ago, Mark92131 said:

With the 292 Cam, the idle is always going to be lumpier than stock.  41 degrees is a lot of advance at 4050 RPM, but you are adding an extra 5 degrees based on the MAP table.  I still think your advance table is too aggressive just off idle.  I would zero out your map table and run a less aggressive advance table to see it helps your under power issue.  Something like this...

 

500 - 3

700 - 10

1000 - 14

1500 - 25

2000 - 31

2500 - 35

2700 - 38

 

I would then set my idle to 1500 RPM and verify that the "ball" is in the middle of the flywheel viewing hole on the transmission.  This will verify that 123 distributor is in synch with the motor timing.  Your Cam manufacturer should have valve lash recommendations, valve adjustment is a good thing.  Once you have this accomplished, then an AFR gauge can determine what jetting adjustments are needed.

 

Mark92131

 

 

 

[Reza Taheri]

It's getting a little better but still feels underpowered and hesitant. But the head gasket does seem to be holding up!

['76mintgrün'02]

Is that voltage gauge on the 123 dashboard accurate?  

 

Have you eliminated the inline resistor wire from the coil's wiring?  The blue coil has a built in resistor, so you need to run a full 12 volts to the + side.

[Reza Taheri]

17 minutes ago, '76mintgrün'02 said:

Is that voltage gauge on the 123 dashboard accurate?  

 

Have you eliminated the inline resistor wire from the coil's wiring?  The blue coil has a built in resistor, so you need to run a full 12 volts to the + side.

I put a voltmeter on the power wire and it was a full 12.xx volts. So I guess the voltage gauge isn't accurate? That is strange 

[Reza Taheri]

1 minute ago, Reza Taheri said:

I put a voltmeter on the power wire and it was a full 12.xx volts. So I guess the voltage gauge isn't accurate? That is strange 

Dammit, on to the next rabbit hole. So I did the same drive in my daily 02 and got these results. I have both dizzys wired the exact same with the same Beru coil (Bosch was backordered). I don't why there would be a discrepancy. Also don't know why my GPS wasn't clocking, but the speedo on the dash showed 75mph

 

[Dudeland]

Perhaps it is your ignition switch.  Try running a relay to give the 123 power to see if the problem stabilizes.  If your charging system was in such bad shape, I think you could tell. 

 

check the grounds... blah blah blah. 

 

 

 

 

. 

[Mark92131]

On 9/17/2023 at 5:51 PM, Reza Taheri said:

It's getting a little better but still feels underpowered and hesitant.

 

Now that the ignition is sorted, time to focus on fuel delivery.  Another rabbit hole of jet changes on that Weber 32/36.  I would first reset the carb using the Redline instructions for best idle and note how many turns out from seated your idle jet is using at your smoothest idle.  This will give you a comparison to the baseline on 2.5 turns out from seated and give you an indication that a idle jet change maybe required.  You could drive that around and see if it runs better.  A better way would require installing an O2 sensor and AFR Gauge so you can map the Air/Fuel Ratio across the entire powerband and easily measure changes (jetting, air correction, etc.).  Or, you could swap on one of those Weber 38/38 clones for $89 and cross your fingers that you got a good one and see if it's a better match for that 292 cam.

 

Mark92131

[Reza Taheri]

9 minutes ago, Mark92131 said:

 

Now that the ignition is sorted, time to focus on fuel delivery.  Another rabbit hole of jet changes on that Weber 32/36.  I would first reset the carb using the Redline instructions for best idle and note how many turns out from seated your idle jet is using at your smoothest idle.  This will give you a comparison to the baseline on 2.5 turns out from seated and give you an indication that a idle jet change maybe required.  You could drive that around and see if it runs better.  A better way would require installing an O2 sensor and AFR Gauge so you can map the Air/Fuel Ratio across the entire powerband and easily measure changes (jetting, air correction, etc.).  Or, you could swap on one of those Weber 38/38 clones for $89 and cross your fingers that you got a good one and see if it's a better match for that 292 cam.

 

Mark92131

I have a gauge but the O2 sensor burns out every couple thousand miles bc of the zinc in the oil. If anyone has a fix for that I'm all ears

[OldRoller]

2 hours ago, Reza Taheri said:

O2 sensor burns out every couple thousand miles bc of the zinc in the oil

I highly doubt your o2 failures are caused by the oil zinc content. I have been running Mobile One (high on the list of zinc content oils) for years in a GMC truck, 2 VW's, and a BMW 740il... all with 100K mils or more. Never had an o2 fail.

Most failures are caused by condensation (sensors mounted low on the pipe vs in the upper sections), excessive oil consumption, or inexpensive sensors. Check your sensor for orientation first. 

[jimk]

O2 sensors don't like silicone, that includes gaskets.

[Reza Taheri]

6 hours ago, OldRoller said:

I highly doubt your o2 failures are caused by the oil zinc content. I have been running Mobile One (high on the list of zinc content oils) for years in a GMC truck, 2 VW's, and a BMW 740il... all with 100K mils or more. Never had an o2 fail.

Most failures are caused by condensation (sensors mounted low on the pipe vs in the upper sections), excessive oil consumption, or inexpensive sensors. Check your sensor for orientation first. 

So my first Bosch O2 sensor was under warranty and I got new one. This one stopped working after a couple thousand miles as well. When I googled it the reason seemed to be zinc. I use the Valvoline VR-1 oil

 

[Reza Taheri]

 

Voltmeter is showing the same result as the 123 gauge. Voltage drops under load