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My ranger is having issues. After running for about 15-30 minutes, it starts to hesitate and stumble under load at about 3k rpm. It progressively gets worse until it’s useless at any rpm under load. If I put it in neutral it will idle ok. I’ve been able to limp home and the next day it will start and run strong for about 15-30 minutes and it all goes downhill again. I have no codes and the check engine light doesn’t come on. I’ve checked all grounds, tested all sensors, and fuel pressure. I’m stumped. Any ides? Thanks
I’m going down this road too. How do I check the egr vac while driving? It only happens while under load, it will rev fine once out of gear. I had it on stands and put it in gear and it’s fine
Ok, did this and no change. I’m going to pull the bed and check the fuel pump. The pressure checks fine but I haven’t tried when it’s hot. I’ll check the grounds volts and pressure hot.
When you said you ran it without a converter you mean the converter removed? Or everything from the converter removed including the converter? Is it possible a chunk of the old converter went downstream and is causing a restriction?? I’d still suggest having a back pressure tester hooked up and drive it til it messes up and see if the gauge registers anything.
I completely removed the converter and put in a test pipe. I fished out all of the matrix that made it downstream. I have since installed a new CC. Still the same issues. I’d rather remove the bed than work on my back plus I can run test leads from the fuel pump into the cab and test the voltage real time when it starts bogging down.
Good idea about voltage checking. Not to sound stupid or anything you sure the brakes aren’t sticking? It’s hard to diagnose when not actually there. Does that year not have a schrader valve on the fuel rail?? Do you have an off 1 scanner? If not maybe run jumper leads from the o2 sensor and monitor voltage. Again no offense we are not there to actually see what’s happening
It has an OBD1 ecu. I have a reader but it doesn’t show any codes. I’ve tested the o2 sensor and it checked out fine. The brakes don’t seem to be locking, I’ve had to push it out of the road a couple of times. Yes there is a schrader valve and the pressure is good but I haven’t set up a rig to test it while I’m driving.
Does your scanner have data stream? If so monitor the upstream o2 sensors to see if it is running rich or lean when the problem occurs that may help confirm if it is a fuel issue or an ignition issue.
I hooked up a fuel Pressure gauge and drove around until it started acting up again. The pressure was good ruling out the fuel pump. Aside from pulling the harness out and checking every inch, any other ideas?