Minimum fuel pressure
#21
04-11-2018, 11:25 PM
Ok I had thought to myself how am i gonna test both ends of this when my ohm meter wires are only 2 ft. Jumper wire huh? Man I feel dumb
so you say disconnect the rear o2 an start her up an see what happens? the truck runs fine 90 percent of the time after I plugged in wires an did the thing with battery’s cables it hasn’t acted up at all as far as meets the eye.
The day I started this thread it was sputtering at an idle like it wanted to die hasn’t done it since then. I should say because i hadn’t before it does have that hiss when it was sputtering. But I had just replaced the IAV back around nov-dec. an just about 2 months ago I had pulled off the throttle body an taped it with about 40 q tips. So I know it isn’t filthy inside of there
Awhile back it seemed like I’d i revved the engine a few times an let off it would act like an old carburetored engine getting flooded out. It doesn’t even do that anymore.
I will work on getting that data in the morning
so you say disconnect the rear o2 an start her up an see what happens? the truck runs fine 90 percent of the time after I plugged in wires an did the thing with battery’s cables it hasn’t acted up at all as far as meets the eye.
The day I started this thread it was sputtering at an idle like it wanted to die hasn’t done it since then. I should say because i hadn’t before it does have that hiss when it was sputtering. But I had just replaced the IAV back around nov-dec. an just about 2 months ago I had pulled off the throttle body an taped it with about 40 q tips. So I know it isn’t filthy inside of there
Awhile back it seemed like I’d i revved the engine a few times an let off it would act like an old carburetored engine getting flooded out. It doesn’t even do that anymore.
I will work on getting that data in the morning
Last edited by beau680; 04-11-2018 at 11:27 PM.
#22
04-12-2018, 07:57 AM
Now I figgur I'll either get grief from others or they just won't care either way...however, IAC's r scapegoated for failure waaaaay too much. Do they get dirty, AYUP...do they fail, ever once in awhile (anything made by man fails), does the HAL9000 hate the aftermkt IAC's, not in my experience. That said, pull the intake air temp sensor n clean it good with some intake/carb cleaner (sensor safe). Those darn things get dirty, especially from blown plenum gaskets and send false temp readings to the ECM. I've seen that cause things like false evap codes (supposedly causing the evap cycle to terminate brfore finishing it's work...or so I've read, but the results I've had...WOW!!!) and IACs (here it comes) to set the rong idle position...not to mention cause our nat'l defense computers to go to defcon 2!!!
#23
04-12-2018, 01:50 PM
#25
04-13-2018, 04:33 PM
Was anyone gonna tell me I pulled the wrong sensor? Lol. But found another issue in the process? 😂actually Two issues , I also found a bad pcv valve.
so I did pull the intake sensor gave it a good cleaning, it had a lot of crude on it.
I have acquired the handled reader an have the new data stored onto it. Unfortunately the screen is about 2-3 inch’s so I couldn’t record it very well.
I can take pics of the print outs once I get them printed. If someone wouldn’t mind taking a look to see if there is any improvement ?
so I did pull the intake sensor gave it a good cleaning, it had a lot of crude on it.
I have acquired the handled reader an have the new data stored onto it. Unfortunately the screen is about 2-3 inch’s so I couldn’t record it very well.
I can take pics of the print outs once I get them printed. If someone wouldn’t mind taking a look to see if there is any improvement ?
#26
04-13-2018, 07:33 PM
#27
04-13-2018, 11:28 PM
ok the first picture is from a stop sign onto a 50 mph highway.
the second pic with the blue thing in the top right corner is from a startup down a 20 mph highway.
I tried to upload a pdf with all this info an some but I couldn't figure out how to do it. so I manually cropped them an made them much more viewable than the first time I posted data
#29
04-13-2018, 11:43 PM
One things for shore, you're cat is shot, possibly even clogging/broken inside, etc. The downstream O2 is all over the place and even goes really high while the upstream tells a different tale. Your trims look fine for the most part...still leaning...but you really need to be at a steady load on the engine. Throttle not moving. Take these readings again in your driveway at idle/1500/2500 RPM. Your engine is all over the place and the ECM is correcting for differing load conditions. Steady load condition and see if your trims, both long n short, steady out somewhere near "0"
#30
04-13-2018, 11:48 PM
If you have access to a thermal gauge, take readings on the inlet and exit of the cat. The exit should be hotter than the intake. This will help ID/pinpoint the cat's condition. If the intake is hotter than the exit, your cat is clogged. If the intake and exit are the same temp, your cat is shot yet still serviceable, again register the temps at idle/1500/2500/3500 RPM to get a feel if the cat is flowing properly. If your exit is hotter than the intake, your cat is okay and your downstream O2 just may be bad.