Sudden power loss and random stalling in neutral

[camP95]

Hey guys. I have a 1995 ranger with the 4.0 liter ohv in my truck. It is a standard. The other day I was passing someone in second gear and when I hit about 4K rpm the engine seemed to do one big misfire and lost all power for a second. I shifted into third and it seemed fine right away again. I just rebuilt my trans, I know it’s not that. I’m wondering if it could have been a momentary vacuum leak? When the vacuum became great enough it sucked in too much air and the engine misfired because the air/fuel mix was super lean? This has happened about three times now where the Engine lost power at high rpm but continues along fine after letting off the throttle. My engine burns no oil and doesn’t leak any. I also have a deleted egr valve and the intake isn’t stock, which does cause the truck to run weird sometimes. It will occasionally stall in neutral out of nowhere. Sometimes won’t do it for a month Then out of nowhere it will stall again only ever in neutral. Oh and my vehicle speed sensor does not work because the plastic gear got chewed up. I’m wondering if anybody knows how these sensors communicate and if they could possibly cause the sudden power loss problem. However this problem is new and it’s never happened before. Thanks for any info. Cheers

 

[RonD]

You need to fix the speedo, get a new gear they are cheap at wrecking yards

Yes, it could be a REV limiter kicking in now and then because speed is at 0MPH
Longshot
1995 is first year of EEC-V computer and has some unique software

VSS(vehicle speed sensor) is a variable reluctance(VR) sensor, from late 1980's to 1997 it was with speedometer cable setup on trans or transfer case tail shaft.
It outputs AC Volts, generates its own voltage, it outputs 8,000PPM(pulses per miles)
In 1995 signal goes to computer, speedometer and cruise

Fuel filter, could be limiting fuel

Could be IAC Valve causing the stall, closes all the way
Does it only stall COLD or only when warmed up?

 

[Canadian_ranger]

i've had my share of weird engine acts like what you,re describing and most of them got fixed through the MAF sensor....It may look clena but it never is. I always carry a can of MAF cleaner and the proper tools to undo it at any time. Tells you how much it can influence your engine.

I'd say clean it up good and see if it keeps bugging