Low power highway speeds

[BennyGGG]

I have the preface this post with: great community here with an insane wealth of knowledge and skill. This forum has been a time and money saver numerous times. All contributors are much appreciated. 
 

I encountered an interesting problem on the way home from work today. I had very little “guts” at highway speeds. I normally set cruise control around 70 and have plenty of power to accelerate up to 80+ without hesitation. Today I basically had to floor it and it felt like someone sapped the power right out of her. 
 

When I got home I poked around the engine bay a bit. Made sure I had good vacuum connections. Nothing out of the ordinary. 
 

I took her back out with my wifi ODB monitor hooked up. The truck was right back to Normal. No issues at all. Plenty of power.  Screenshots attached. 

 

what do you guys think? What should I be looking for if this issue comes back? Thoughts?
 

I have a full suite of gauges coming in this week. Fuel pressure, EGT, trans temp and boost. Hopefully if it happens again I can have more info to pass along. 
 

2001 2500 4x4 47re leveled on 34s. Engine/drivetrain is stock except for an edge EZ. 

[Dieselfuture]

Boost fooler may be not functioning or map sensor going waky

[Silverwolf2691]

22 psi seems awfully high at 1800 rpm with only 30% throttle..

 

Vacuum doesn't matter as much on a diesel..

 

Intake MAP is 36.83 psia, so minus 14.7 for 22.13 psig.. 0.2 psi is enough to account for elevation.. 

 

Any codes set? I wonder if your timing went wonky in the vp44..  

[Mopar1973Man]

Standard math can't be used to correct map values for boost. I've tired many time but does hold any accuracy. Best to have a boost gauge.

[BennyGGG]

1 hour ago, Silverwolf2691 said:

22 psi seems awfully high at 1800 rpm with only 30% throttle..

 

Vacuum doesn't matter as much on a diesel..

 

Intake MAP is 36.83 psia, so minus 14.7 for 22.13 psig.. 0.2 psi is enough to account for elevation.. 

 

Any codes set? I wonder if your timing went wonky in the vp44..  

no codes. Truck is acting normal. I commute to work 2 days a week so I’ll keep the OBD reader running and see if it comes back. 

[Mopar1973Man]

So on boost values it's difficult to read with any OBDII live data tool. Being it not simple math. Now as for testing I would ohm test between the MAP plug and ECM plug. Should be 0 ohm no more than 5 ohms. Now with both plugs unhooked you need to test between a pin and ground to verify no shorts to ground. It should read infinite ohms. If all that checks out I would consider new MAP sensor and possibly having the ECM tested.

 

Also I seen you have a Edge EZ it's possible the module got water in it and the circuit board will be corroded. It's also possible the boost fooler is shot. Try unplugging all that and test again.

[BennyGGG]

On 10/16/2021 at 7:25 AM, Mopar1973Man said:

So on boost values it's difficult to read with any OBDII live data tool. Being it not simple math. Now as for testing I would ohm test between the MAP plug and ECM plug. Should be 0 ohm no more than 5 ohms. Now with both plugs unhooked you need to test between a pin and ground to verify no shorts to ground. It should read infinite ohms. If all that checks out I would consider new MAP sensor and possibly having the ECM tested.

 

Also I seen you have a Edge EZ it's possible the module got water in it and the circuit board will be corroded. It's also possible the boost fooler is shot. Try unplugging all that and test again.

I’ll check all this tomorrow. I appreciate the info. 

[BennyGGG]

Finally got around to checking everything. MAP to ECM rings good and no shorts. Cleaned all the connections with some isopropyl and added some silicone to the rubber gaskets. Took apart the edge EZ. Nearly the entire unit is potted with only a few components visible. Nothing out of the ordinary. I cleaned and siliconed the connections. The problem still has not come back but if it does I’ll update the post. Is there a particular brand of MAP I should consider? 

[Mopar1973Man]

Lets just say a good MAP sensor will be close to $100. Cheap china knock offs will be much much cheaper.