jrd Posted January 3, 2008 Share Posted January 3, 2008 Hi all, Still trying to trouble-shoot my megasquirt installation. 2.9L L28, NA. Using Flyback circuit. I am looking at my datalog and I am having these jumps in the injector pulse widths that are random. Just cruising along and the PW doubles briefly. This causes the car to bog down temporarily as it floods. There is no corresponding change in the TPS that should be causing it although the MAP does change after the event. Any ideas what it could be? Thanks, Joe Quote Link to comment Share on other sites More sharing options...
Zmanco Posted January 4, 2008 Share Posted January 4, 2008 I would suggest you datalog it, and then look at what else is changing when the PW jumps up. For example, noise on the MAP signal might make MS think that you've suddenly go a lot more air flowing into the engine. Quote Link to comment Share on other sites More sharing options...
jrd Posted January 4, 2008 Author Share Posted January 4, 2008 Dataloging is how I found out that it was happening. Pulse width is jumping up without any apparent reason.... What I mean is nothing else is changing to cause it.... I am confused. If it were noise on the TPS then that would show up.... Joe Quote Link to comment Share on other sites More sharing options...
Zmanco Posted January 4, 2008 Share Posted January 4, 2008 Sorry, I missed that you found it from the datalog Have you gone back to the datalog and looked at all the other signals such as MAP, O2, CLT, batt V, etc? If the MS unit itself is functioning properly, then one of the other parameters should be changing at the same time as the PW. Just a thought, are you running the latest version of MS firmware? You might reload it anyway. I've seen posts on the MS site where people have solved this type of random issue with a reload. I'm a bit skeptical that this would help, but if you run out of other ideas, it's something else to try. Good luck! Quote Link to comment Share on other sites More sharing options...
jrd Posted January 4, 2008 Author Share Posted January 4, 2008 Thanks Daniel, I think that I found it, but what was confusing was that nothing else was changing. It appears that my accel trigger level was too low. I bumped it up and it didn't do it nearly as much. Gonna bump it up a little bit more.... Now if I can just solve me starting issues I will be happy. Joe Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted January 5, 2008 Share Posted January 5, 2008 You should be able to find it somewhere in the tune/datalog. If you are datalogging the pulsewidth change that means something in the map or a loose sensor is TELLING it to change. If it was some sort of electrical problem with the injectors it would NOT show up in the logs. The logs show what MS thinks it should be running. Recheck all sensors that have an effect. This includes coolant, MAP, TPS, IAT, etc. etc. Try datalogging everything with the key on and engine off. Walk around and jiggle the sensors, the wiring, the grounds, etc. Quote Link to comment Share on other sites More sharing options...
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