Can't keep 5.3 running. RPM bounces up and down and then dies. (log file incl.)
I have a 5.3 on engine stand in my garage and it will start and run pretty good until it warms up. It seems to be about before it enters closed loop so i don't think it's O2's. It will all of a sudden drop about 100 rpm, try to catch up and jump about 200 then repeat like that for 10 seconds or so in an oscillating pattern. Then it will eventually shut itself off after the last gasp.
Last edited by bubba68ss; November 14th, 2014 at 07:13 PM.
Which PID's can I monitor to figure out what is causing engine to die at idle once its warmed up?
Last edited by bubba68ss; November 13th, 2014 at 12:31 AM.
Sparkadv, ltft1/2, map, maf, ect, iat, rpm, dynair, ftc.
I logged those and everything looks good except ltfts are pegged at 25 and spark advance is bouncing around between 5 and 30. Map is steady, maf flows good... Manifold vacuum at idle is 10psi but don't know if that's good. Fuel pressure is 48psi with vacuum hooked up and 55 without. Have tried flat injector rates and sloped. No real difference.
When I snap the throttle it has a slight delay, revs and then boys and sometimes dies.
would appreciate it if someone could take a look at this short log and tel me if they can see the culprit.
Running a stock 2002 silverado 5.3 tune
Log_0010.efi
To save some time running log, here is a screenshot. WTH is going on here?
Last edited by bubba68ss; November 14th, 2014 at 08:19 PM.
Engine is misfiring on all cylinders, spark is falling because of it, LTFT's are super high because there is either fuel starvation or huge vacuum leak. Does this sound right?
If you rail pressure is correct, I suspect a vacuum leak.
Vacuum is about right at 10 psi (VAC 66 kPa, MAP 33 kPA).Originally Posted by bubba68ss
Rail pressure at 55 psi is close (should be 58 psi +/- 1 psi... but 55 psi should be ok).
How big of a leak would it have to be to produce max LTFT's? I would think i would hear it, right?
Would running my wideband during open loop tell me anything? Closed loop?
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