Update on my 5.0, still need some help...timing issue

[south59]

As some of you might know, I've had a pre-detonation problem lately on my truck that seems to occur in low rpm's when the truck is under load, especially in overdrive.

I was able to purchase an OBD-2 scantool from www.Autoenginuity.com which I am very happy with. Now I'm not the best troubleshooter yet, but I did notice that in one of my datalogs from a short trip to the store and back that my timing advance is way too high(or at least i think it is). It fluctuates from around 18 degress at idle to a constant 40degrees at higher speeds. I've attached an excel datalog sheet that hopefully some of you guys can look at along with some of the other readings so I can get this fixed!

https://webspace.utexas.edu/jm3474/academy home.xml

The truck is a 96 v8 with 142,000 miles. new plugs(gapped properly) along with wires. the maf is clean, and the truck isnt throwing any codes.

I can hook up the scantool to monitor anything you guys would like further readings on. Thanks in advance!

 

[CDW6212R]

My 98 with 147k has started to ping lately. It never pinged for the first two years that I had it. Likely the cause is a combination of O2 sensors, plugs/wires, or internal chamber carbon.

Consider running some cleaner additives through the engine. SeaFoam is a common pruduct which many have sworn by. Be careful and follow the instructions carefully. I have wires and O2 sensors on my list of items to change, and SeaFoam. Good luck,

 

[south59]

My 98 with 147k has started to ping lately. It never pinged for the first two years that I had it. Likely the cause is a combination of O2 sensors, plugs/wires, or internal chamber carbon.

Consider running some cleaner additives through the engine. SeaFoam is a common pruduct which many have sworn by. Be careful and follow the instructions carefully. I have wires and O2 sensors on my list of items to change, and SeaFoam. Good luck,

i wish it was as simple as a can of seafoam... i've run 2 cans through and noticed nothing different. As for the o2 sensors, I'm not sure

 

[south59]

This started happening after I bought an X-calibrator that didn't want to work on my truck...It would detonate so bad that the truck wouldnt even go more than like 15mph ....and now i just realized that my current problem with detonation has developed as a direct result of that. Could my PCM be bad?

 

[performancenut]

This started happening after I bought an X-calibrator that didn't want to work on my truck...It would detonate so bad that the truck wouldnt even go more than like 15mph ....and now i just realized that my current problem with detonation has developed as a direct result of that. Could my PCM be bad?

Bad PCM is a finding of exclusion. A swap with another PCM from 1996 or 1997 5.0 would help diagnose this by being able to eliminate the problem. Have you cleaned the MAF sensor? Running a K&N air filter or similar filter with filter oil that could have contaminated the MAF? If you have not done it lately, I would suggest a MAF cleaning. Sometimes a lower temp. thermostat eliminates the detonation also. The programmer issue may just be a preexisting problem that manifested more with performance tuning and continues even with the stock program.

 

[CDW6212R]

Good points, and there could be more. Look into the simple stuff first, cleaning and normal tune up items. Make sure that all maintenance is good, before looking into complicated and expensive things. Good luck,

 

[south59]

well, i put 3 gallons of 93 octane in the truck just to see how it ran, andthe truck seems to be running a little better, but still detonates just as bad in overdrive mainly under low to moderate acceleration. I'm going to datalog a trip from Austin to Houston this weekend, and hope to find the problem then. While im in Houston, im going to replace the fuel filter as a start to troubleshooting this....

Other things that I have thought as being the culprits:
-EGR Malfunction
-Injectors

 

[south59]

Bad PCM is a finding of exclusion. A swap with another PCM from 1996 or 1997 5.0 would help diagnose this by being able to eliminate the problem. Have you cleaned the MAF sensor? Running a K&N air filter or similar filter with filter oil that could have contaminated the MAF? If you have not done it lately, I would suggest a MAF cleaning. Sometimes a lower temp. thermostat eliminates the detonation also. The programmer issue may just be a preexisting problem that manifested more with performance tuning and continues even with the stock program.

I'll try looking for a PCM i guess on ebay and buy one if the price is right. The maf is clean, and ill look into getting a 180 degree thermostat just to see how it runs with it in. Thanks for your help

 

[IAmTodd]

I've had bad pinging all Summer. The combo of running 89/sea foam/and acetone through it has helped. But I just did a 500 mile trip this weekend and in the areas of 65-75MPH it will ping like mad. I would like to know a solution for this instead of just dumping chemicals and more expensive gas in it.

 

[south59]

update, i changed the graph to be easier on the eyes...I don't see anything out of the ordinary except the timing issue....which escalates when i start to notice the detonation at around 45mph all the way up till when the RPMs are high enough and the truck sounds normal again...HELP!

https://webspace.utexas.edu/jm3474/academy home.xml

 

[south59]

 

[exploded99]

Timing does look pretty advanced at idle - 18.5 degrees. You are at sea level essentially. A stock engine will normally be 6 to 12 degrees at sea level. Here in Denver you add about 6 degrees to compensate for the high altitude - I would expect to see those readings in Colorado.

Do you have access to the timing tables for this engine as published by Ford? I am not positive 18.5 is wrong, just suspicious that may be too advanced.

Your engine temp seems stable - I don't think thats an issue. Going to 180 degrees will possibly richen the mixture - you may cause the engine to believe it is not fully warmed up. Don't know the specific temp at which the computer treats the engine as fully warmed up. But the computer richens the fuel mixture below operating temperature - which will cut mileage.

I think your Excalibrator may have messed up something in your PCM when it flashed it. There is supposed to be a way to use the Excalibrator to return the PCM to factory stock programming by re-flashing it. Have you tried that?

 

[south59]

Timing does look pretty advanced at idle - 18.5 degrees. You are at sea level essentially. A stock engine will normally be 6 to 12 degrees at sea level. Here in Denver you add about 6 degrees to compensate for the high altitude - I would expect to see those readings in Colorado.

Do you have access to the timing tables for this engine as published by Ford? I am not positive 18.5 is wrong, just suspicious that may be too advanced.

Your engine temp seems stable - I don't think thats an issue. Going to 180 degrees will possibly richen the mixture - you may cause the engine to believe it is not fully warmed up. Don't know the specific temp at which the computer treats the engine as fully warmed up. But the computer richens the fuel mixture below operating temperature - which will cut mileage.

I think your Excalibrator may have messed up something in your PCM when it flashed it. There is supposed to be a way to use the Excalibrator to return the PCM to factory stock programming by re-flashing it. Have you tried that?

I've heard any value between +- 12 is good for idle/1500/2500 or WOT on a stock PCM. What im worried about is the huge advance when i actually begin to hear the detonation... It CANT be good for the engine to be compensating that much for whatever is causing this problem.

As for the cooling aspect, the truck has a brand new thermostat and coolant temperature sender..so i would hope it would be getting the right signal. I might try a 180 degree just for ***** and giggles though.

Finally, as for the X-calibrator...Its somehow related to it not functioning correctly on my truck...As for how it messed it up, I dont know. Maybe the stock timing values that the X-calibrator sent to the PCM are incorrect. Or it could have triggered an already pre-existing problem.

 

[performancenut]

I've heard any value between +- 12 is good for idle/1500/2500 or WOT on a stock PCM. What im worried about is the huge advance when i actually begin to hear the detonation... It CANT be good for the engine to be compensating that much for whatever is causing this problem.

As for the cooling aspect, the truck has a brand new thermostat and coolant temperature sender..so i would hope it would be getting the right signal. I might try a 180 degree just for ***** and giggles though.

Finally, as for the X-calibrator...Its somehow related to it not functioning correctly on my truck...As for how it messed it up, I dont know. Maybe the stock timing values that the X-calibrator sent to the PCM are incorrect. Or it could have triggered an already pre-existing problem.

How about contacting the web site for the Superchips/Xcalibrator and ask if they have any experience with this complaint.