Dyno tune ended prematurely!

[JOHNDIXON]

So ive got the ported eaton back together, had the shop install a bap and tune. My tuner says ive got a problem; the fuel pressure duty cycle is bouncing up and down messing with the a/f. Starts to do it at higher rpms. he thinks theres a problem with the pprv delete which i had planned to do previously and dropped my tank to find that it had already been done and looked good. ne ways i dropped the tank again today and put a new kit in cause he was so convinced, but still didn't see anything. I guess my question is what else could cause this fp duty cycle to jump around?

 

[cobracide]

Voltage, datalog that too. Also, you have a wire upgrade to the fuel setup? It would really help if you listed you mods or put them in your sig when when asking questions on your setup. So, your tuner doesn't know what to look for?

 

[JOHNDIXON]

Updated sig, ive got the wire upgrade on order aswell as the fore hat. Im in the process of finding other sources for tuning, unfortunetly not many options around here. When u say datalog voltage does this mean a bad alternator could cause this or possisbly an overdriven alternator because its still stock pullied. im strapping on a 2.3 soon so id like to find the culprit before upping the power.

 

[redfr03svtsnake]

Well let me say this, ive had some weird issues just as that. I replaced plugs fuel filters, put in upgraded pumps, on and on, it wound up being two coil packs being bad. This basically caused it to run rich, comp would compensate, cut fuel, go lean, this also showed eratic fuel pressure spikes. I have a wideband, and watched the lean/rich go crazy. Check COPs..... that might be where the problem lies.

 

[JOHNDIXON]

what have you found to be the best way to find a troubled COP?

 

[Stalker27]

^^ I have read you can test it by with the motor running slightly pull one COP out at a time. You are listening for a tick sound (which is good). If you pull one and hear nothing then you found the bad one. Once again that's what I've read