ECMlink Fuel pressure issue

[jpmxrider489]

So I am having a weird issue involving my fuel pressure. If you look at my log, it seems the issue happens most of the time above 5k. My rev limit is 8500. I cant find out why the pressure would randomly drop. Most of the time at the end of the pull. Does this look like a misfire? I highly doubt it because the plugs are brand new.

I have checked the fuel system for leaks. I have tested my afpr on the bench and in the car. I cant seem to replicate the issue. In the log when the fuel pressure drops, the CC and injector duty does not drop. My voltage does not drop. I have never seen this issue before or read about it. If you need more info let me know. Also in the log, I build boost at idle to see if it replicated but it didnt.

 

[Vegas Smith]

The only thing I can think of is the wiring for the pump is bad or the pump itself is bad in some strange way.

 

[AWD-Tony]

Try a different source for the afpr

 

[jpmxrider489]

The only thing I can think of is the wiring for the pump is bad or the pump itself is bad in some strange way.

If the wiring was bad wouldn't see voltage drops? The wiring appears fine. Again I been running this for a while now. Plus the issue is always right before me letting off throttle. Bad wiring would be more intermittent?

Try a different source for the afpr

The afr line is going to a vibrant vacume block. Feeding the block is two -4 lines. The block is only feeding my fpr, boost gauge and map sensor. I dont see any change or drops in the items installed in the block. That kind of tells me that everything is fine with the lines.

These pulls were all done on a flat straight road. But could this be sloshing with a quarter tank.

 

[jpmxrider489]

I notice in the log that I forgot to check the auto trans and disable clutch cut. Unlikely but would this have anything to do with this?

What exactly does the auto trans check box do beside mess with boost table?

 

[Vegas Smith]

If the wiring was bad wouldn't see voltage drops? The wiring appears fine. Again I been running this for a while now. Plus the issue is always right before me letting off throttle. Bad wiring would be more intermittent?



The afr line is going to a vibrant vacume block. Feeding the block is two -4 lines. The block is only feeding my fpr, boost gauge and map sensor. I dont see any change or drops in the items installed in the block. That kind of tells me that everything is fine with the lines.

These pulls were all done on a flat straight road. But could this be sloshing with a quarter tank.

You would see voltage drops at the actual pump but probably not on the ecmlink battery value. I don't think it's the afpr vacuum source because the pressure dips below the minimum base pressure. Even if you blocked the vacuum line the car should always have the base pressure and never, for example, 20psi as shown in the log.
The drop in pressure looks to be too steep to be real if you ask me. Is there an actual problem you're having or is it something you noticed on the log? Try locking the mdp sensor and see if that helps. I suspect that it's just a wiring issue with the fuel pressure sensor. Maybe the wiring is jangling around when you hit that torque spike around 5k.

 

[jpmxrider489]

You would see voltage drops at the actual pump but probably not on the ecmlink battery value. I don't think it's the afpr vacuum source because the pressure dips below the minimum base pressure. Even if you blocked the vacuum line the car should always have the base pressure and never, for example, 20psi as shown in the log.
The drop in pressure looks to be too steep to be real if you ask me. Is there an actual problem you're having or is it something you noticed on the log? Try locking the mdp sensor and see if that helps. I suspect that it's just a wiring issue with the fuel pressure sensor. Maybe the wiring is jangling around when you hit that torque spike around 5k.

I will check the wiring, relay, and crimps. I am having a issue and it is indeed real. I confirmed that my aem gauge also dips which is installed in the regualtor. The car just hits a wall when this happens and I immediately let off. Look at the knock value to.

 

[Vegas Smith]

Yeah, it does appear to be something mechanical now that I take a second look. What fuel pump are you running?

 

[jpmxrider489]

Yeah, it does appear to be something mechanical now that I take a second look. What fuel pump are you running?

I am running the wally 525. I went over all the electrical and everything is fine. I cleaned out the fuel filter and changed the gas without change. To me the fuel system is a simple desigh. Im not sure why this is happening. If it was a boost/vacume issue, I would see the boost issue with this. The other thing, in the log, youll see it starts to knock before the fuel drop. Not sure if that is relivant or not.

 

[Vegas Smith]

At this point I wonder if it’s a 5v sensor issue. I can’t remember the complete list of 5v sensors but I know it’s tps and mdp. I wonder if the fuel pressure sensor, map and tps are all losing power for some reason.

 

[jpmxrider489]

At this point I wonder if it’s a 5v sensor issue. I can’t remember the complete list of 5v sensors but I know it’s tps and mdp. I wonder if the fuel pressure sensor, map and tps are all losing power for some reason.

MDP, Baro, tps, and maybe EGR. I will check that area if the car tomorow. I highly doubt I'll be loosing power because I did a complete overhaul on wiring.

If it was fuel starvation, would my duty cycle and fuel flow show that in the log?

Also, the automatic trans check box. Does that do more than just effect the boost table?