Acts like it has a 4500rpm rev limiter

I've owned this 1995 truck since 2005. It had 175K mi when I bought it. Now it has 217K.
I never abused or hot rodded it. Last year I decided to stomp on the gas and see what it would do.
It cut out at 4500 rpm, like it had a rev limiter. It does it in every gear, even neutral.

The original crank sensor quit (truck wouldn't start) and I replaced it. I've replaced the crank sensor a second time with no change. No engine light on dash. My mechanic can find nothing wrong. The timing belt didn't jump. The truck runs great except for that. Manual 5sp, 4WD.

I've seen other posts with same problem, but the rpms varied. Some were 3500rpm. None of the fixes mentioned seem to apply to my truck.
I can still drive the truck but this problem keeps nagging me in my head.

Any advice or help would be greatly appreciated.
Thanks

 

Maybe new ignition coils will perk it up

 

Thanks. That's a good idea. I don't know why that never even crossed my mind......or my mechanic's. I would bet they are original. I'm going to do that.
Thanks again.

 

Possibly your MAF. A faulty MAF will limit your RPM throw and bog out.

While cruising or from a dead stop, what happen when you WOT?

 

It might be a good idea to verify the accuracy of the tach by monitoring live data, or use a photo tach. Maybe it IS revving to redline, but the tach in the gauge cluster is reading low?

 

Does it feel and sound like it’s stopping at 4500?

 

You must hate your truck. I apologize to mine if it hits 3500

 

If you have ever hit a rev limiter on a vehicle you know it has a distinct sound and feel. Is that actually what happens?

How have you verified the tach is accurate? BTW, it can be accurate in the low RPMs and off in the higher.

A sign of a clogging fuel filter is pooping out at high RPM. Same with a clogging exhaust stream.

Doing that in neutral is a great way to never worry about how high it revs again.

 

When was your last tune up?? Things like that can all add up.

How do your spark plugs look ?

When was the fuel filter last changed??

Did your mechanic do a compression test ?? After all it is getting up there in age.

 

Not sure how to reply to individual posts, so I'll reply to the last 4 here:

Fuel filter has been changed. I never checked tach accuracy, but I will, if I can figure out how.
I don't hate my truck. I've owned this thing for almost 20yrs and last year was the 1st time that I recall hitting 4500rpm. I only revved it in neutral once, to see if no load made any difference.
When you floor it, it accelerates as it should until 4500rpm. It cuts out, pops and bucks. Pretty violent. I will clean the MAF and see.
I've only seen rev limiters in action on videos. My truck bucks pretty violently at 4500rpm. I would say it's similar, but not the same thing?
I have had a tune up. If the mechanic did a compression test, he didn't tell me.

You all have given me some good ideas to check and recheck. I am leaning towards coil pack replacement, for sure. I believe they are original.

Thank you all for replying

 

Which crank position sensors have you used?

Mine is one of those that did this at 3500 rpm. Replaced the sensor with a Denso brand from RockAuto. It did help a bit, but did not fix it entirely. Last time I tried to find the limits, it starts to cut out at ~4200-4300 rpm. The rpm readings from the dash and from the scangauge are consistent.

FWIW, I am running a supercharger with a Haltech piggyback system so no MAF. New injectors, new spark plugs, new high volume fuel pump and new fuel filter.

 

Shit I smack limiter a few times for good measure each drive. Let it eat, hell get an aftermarket computer and raise the limiter to 6k. Gotta feed it the onions and clear it out once in a while.

 

You should be able to pull 5k out of that Bitch in neutral then drop the hammer into 1st. Please video tape this event

 

Crankshaft and camshaft sensor if not oem can be an issue,
Did you replace both?
Check ground wires too and ecu ground wire

 

I don't know who made the 1st replacement crank sensor. It is unmarked. The new one is an ImportDirect part. I have learned in the last few months from watching YouTube Toyota mechanics - replace critical components, like sensors, with factory Toyota parts only.
Great - now I can't rule out that I have a faulty crank sensor.
Does a 95 have a cam sensor?

 

On the plus side, there is nothing past 4500 worth reving for. It signs off right about there.

 

YIKES

 

My reason for concern is, if something is going bad, I don't want to be stranded somewhere if it gets worse - or quits altogether.

 

Done it on 33s and a dry lake bed, takes off hard.

 

Yes, I now know that my ImportDirect crank sensor could still be the culprit. Checking grounds is another very good idea. I have not done that. Thanks.