You seem to have mad skills so I almost hate to venture a guess, I also know with out a cam timing kit that it’s a pain to check, but could you be off a tooth when you replaced the timing chain? Just trying to come up with something for you.
14CUX running rich
- Thread starter p m
- Start date
Given with having installed the sprockets 90 degrees off, it is not inconceivable. But my ordeal started with the engine skipping a tooth - and does it run like shit when that happens. I had to use side streets and low range at every grade to get home. So, hopefully, it is not the case - we've taken this truck from San Diego to El Camino Del Diablo and on to New Mexico border, and it ran well if a little thirsty.
But the truth is - I don't know for sure.
It has to be something stupid.
One thing I noticed is that there's no air intake for the crankcase - two of my 95s have a small port at the back of the driver side valve cover, with the vacuum hose going to the port on the air filter housing. This one does not, and the port seems to be plugged with something.
But again, it ran fine before.
After another pointless fifteen minutes with the motor -
Both short-term lambda (fuel) trims show full-rich; the exhaust smells a bit rich, but not terribly. If you look at the plot - the engine RPM drops when the injector pulse width increases.
I wish I could have a faster sampling rate - this is barely resolved (~4 readouts/period of oscillation).
Both short-term lambda (fuel) trims show full-rich; the exhaust smells a bit rich, but not terribly. If you look at the plot - the engine RPM drops when the injector pulse width increases.
I wish I could have a faster sampling rate - this is barely resolved (~4 readouts/period of oscillation).
Amazing diagnostic work here Peter. I’m hoping I never have to go this deep.
my new 93RRc had an idle issue show up after my first long drive , where it idled terrible low and would stall when there was no load on the engine (came to a stop light). I cleaned MaF, AIC, TPS and so far this has worked, however if it hadn't my next step was actually around fuel pressure. When I filled my tank for the first and only time, there was a shcoking amount of pressure built up, that released when I took the cap off..that had me concerned that my evap system was plugged or something.
my new 93RRc had an idle issue show up after my first long drive , where it idled terrible low and would stall when there was no load on the engine (came to a stop light). I cleaned MaF, AIC, TPS and so far this has worked, however if it hadn't my next step was actually around fuel pressure. When I filled my tank for the first and only time, there was a shcoking amount of pressure built up, that released when I took the cap off..that had me concerned that my evap system was plugged or something.
Rob, that thing just drives me a little insane. Especially since I have another 95 Classic next to it running perfectly well.
The adjustment screws on both MAF sensor and throttle body were uncapped on this truck and clearly messed with - so it did have some idling problems in the past.
I have to clarify the intent: I can definitely make this engine idle perfectly well. I just can't make it idle well and likely pass a smog check.
The adjustment screws on both MAF sensor and throttle body were uncapped on this truck and clearly messed with - so it did have some idling problems in the past.
I have to clarify the intent: I can definitely make this engine idle perfectly well. I just can't make it idle well and likely pass a smog check.
What’s difficult about trying a different ECU? It should be pretty easy. I’ve had mine out several times. Maybe takes 10 minutes at the most.
And your original gauge pic shows the throttle % hit 96%. Maybe try a different TPS if it’s sending an artificially high readding..
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In a 95, the ECU is sandwiched between other shiznits behind the glovebox. Even taking the ECU connector off is difficult.
What's wrong with throttle hitting 96% open? The app sets the extents regardless of whether the engine is running or not.
TPS has been checked and rechecked many times. It is not a problem.
It was the MAF sensor.
Probably just dirty as sin - enough to introduce a delay into the control loop to make it unstable.
Probably just dirty as sin - enough to introduce a delay into the control loop to make it unstable.