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				Has anyone ever tried to log fuel pressure?  fueling issues
				Posted: Sat Jun 27, 2009 4:23 pm
				by dbsharp
				I have been having a strange problem with my car for a while now.  I would like to try to datalog my fuel pressure to be sure that is not the cause or part of the cause.  I want to know know if anyone has done this before, and what equipment/ setup they used to do so.    My problem:    -occasional hard starts.  -lean at idle occasionally (18-19+ afr).  -random stalling (usually lean idle afrs during this event).  -My tune seems to drift off over time.  I tuned the my car to have around 14.5-15 afr through the part throttle.  It stayed like that for a while and now part throttle is mostly 16-17 afr.  It did this on crome too.  -the other day during wot pull the car had a random lean spike.  map, injector duration, and rpm were all consistent and steady throughout the run.  Afr's were 13-13.1 and then there was a random lean spike to 14.1 for a brief moment.    What I have done to correct this problem:  -Replaced injectors  -Replaced fpr  -Replaced ecu  -tried different tuning programs  -tested injector wires and resistors, and other key components of wiring harness  -ensured proper grounds  -I have a walbro 255 with less than 20k miles. I also tested power supply and ground when I replaced it.  -fuel filter is new      What I plan on doing:  -I have a new engine bay wiring harness that I'm going to throughly test before installing.  I might also replace the ecu's wiring harness.   -I want to test the pgmfi main relay  -I want to retest/ possibly upgrade fuel pump circuitry  -log fuel pressure  -get some gas and torch the dam car, lol.
			 
			
					
				
				Posted: Sat Jun 27, 2009 10:26 pm
				by Bugermass
				The best fix for the problem.. Buy a new car.. 

    Its so nice to have a new car that has no problems.. just drive it and put gas in it..       But, yeah to log fuel pressure isn't to hard, just get a el cheapo electric FP guage from the auto parts and run the outputs of it into a voltage input on the ECU.. Then you can datalog the pressure. I don't remeber which pinouts are voltage inputs off hand, I'm sure somone can chime in here and help with that.
 
			 
			
					
				
				Posted: Sun Jun 28, 2009 12:47 am
				by pb16b
				throw any codes?  i was having a similar problem and it turned out to be the pgmfi relay.
			 
			
					
				
				Posted: Sun Jun 28, 2009 1:24 pm
				by dbsharp
				no codes. LOL that would be too easy.        \"The best fix for the problem.. Buy a new car.. Wink  Its so nice to have a new car that has no problems.. just drive it and put gas in it.. \"    God that would be nice.  I want nothing more than a nice reliable dd.  Gotta find a good job first.  Thats hard these days even with a degree.    Ill look into a cheepie electronic fuel pressure gauge.
			 
			
					
				
				Posted: Sun Jun 28, 2009 3:25 pm
				by thething96
				I'm having the exact same issue, but my car runs richer than before, ever after retuning. I'm under the impression that it might be a map sensor issue.....
			 
			
					
				
				Posted: Mon Jun 29, 2009 7:31 am
				by cbustuner
				I'm going to try and log fuel pressure here soon.It seems pretty easy. Buy this sensor    
http://auberins.com/index.php?main_page ... cts_id=125    and a 1.29 voltage regulator at radio shack, wire everything up and just hook the output on the sensor to one of the 0-5v inputs on the ecu.That sensor even comes with the voltage tables to put in to ectune.
 
			 
			
					
				
				Posted: Mon Jun 29, 2009 9:11 pm
				by dbsharp
				Being the high roller that I am, I bought some glow shift gauges and an a pillar pod for them.  I am upgrading my ricer status.  lol.      At least now Ill be able to keep an eye on fuel and oil pressure at all times.      I am probably going to buy a main relay when I get around to buying my ac parts.
			 
			
					
				
				Posted: Mon Jul 20, 2009 4:29 pm
				by dbsharp
				OK fuel pressure is rock solid.      I have a log where my afr is just going completely nuts.  I don't think its the wideband acting up because of all the other fuel related problems I have, but I am not going to rule that out.