The truck drives fine unless I'm towing a hill, or maybe have a headwind on a flat. As I give it more throttle, it starts making a ticking sound, like a leaf stuck in the A/C vent and fluttering -- except in the engine compartment. The ticking gets louder as the truck loses steam, then begins to shudder. Not violently, but you can feel/hear it. RPMs get up around 2500 but rarely higher, but speed is still around 40 so the truck won't downshift to 1st. It's just not making the power needed. It doesn't die; it just pulls like my old IDI
Using AutoEnginuity I did the WOT
test up a long straight hill; injection pressure spiked to 3000, held briefly at 2800, then faded to ~2600 and stayed there. IPR
duty cycle is low teens at idle, ramps gradually to around 40%, and when the "ticking" noise starts it climbs more, sometimes hitting the 70s while the truck is shuddering. I happened to log RPMs too, and when the shuddering starts, RPMs are doing a rapid oscillation of about +/- 50 RPM. Too fast for the dash tach to register it.
I don't have a boost gauge but AutoEnginuity showed 26psi for the MAP
sensor during the WOT
test above -- minus about 12 psi
atmospheric (I'm at 5k feet) means ~14psi boost, right? Is that low enough to cause this issue? When I monitor the Wastegate position with AE
it pretty much always shows 99.11%. I only see it briefly flare open once in a while as I come over the top of a hill. I've also noticed black soot on the tailpipe. I didn't think to monitor EBP
during the WOT
test but I'm wondering if that could be the problem?
This was happening before I put in fresh injectors (stock remans from FullForce Diesel), but was much worse -- I was expecting the new injectors to solve it completely but it seems there's something else going on. The only code showing is P1211
"injector pressure higher/lower than desired". I have a pretty new ICP
sensor, but have not touched the IPR
yet. Fuel pressure from the tank stays steady at 60psi at all times. New fuel, oil, and air filters. New boots on the intercooler pipes and from the spider to the plenum. UVCH is new. No chips, tuners, or mods. The turbo is not original; P.O. evidently put in a Garrett P38, so I'm hesitant to say the turbo itself is the problem since it can't be all that old.
I'd be very grateful for suggestions or ideas, other tests I should try, etc. Thank you all!