Engine won't accelerate past 2800 rpm. Whats goin on?

I have a 1987 Nissan Pick-Up with the Z-24 4cyl engine. I drove it to the store one day and it was running fine, when I came out it would not rev past 2800rpm. I have tried numerous things and can not get the problem fixed. I believe it is a problem with the spark because it is getting plenty of fuel, and it isnt sputtering out, it just hits 2800rpm and the needle bounces. It does this in every gear. Other than that the truck runs and starts great. I havent found any vacum leaks or wires disconnected. I have replaced the coils, plugs, distributor cap and rotor. Everything seems to be getting a good ground also. I'm about to break down and take it to a mechanic but I would rather not. If anyone has any idea of what it might be I would greatly appreciate the input. Thank you in advance.

- Joel -

[James]

air flow sensor.

OK I'll be checking that next. Thank you.

[200sx Se-T]

Hmmm, this is a complacated one... you said it wasn't spuddering or backfireing (sp?) I would say change the plugs and wires... I did a tune up on a altima one time and I switched the 2 and 3 wires and that wouldnt rev past 2800 Lmao but it also backfired like crazy and studdered all over the place.

[James]

Originally posted by 200sx Se-T
Hmmm, this is a complacated one... you said it wasn't spuddering or backfireing (sp?) I would say change the plugs and wires... I did a tune up on a altima one time and I switched the 2 and 3 wires and that wouldnt rev past 2800 Lmao but it also backfired like crazy and studdered all over the place.

Complicated my ass... it's a MAF sensor... if you ever had one go out you'd know exactly it's this problem! The ecu will not let you rev past about 3k rpm and the injectors jump out of sequential mode and start spraying twice per rpm... the car will run rich and you will get black crap spewing out the back of your exhaust pipe...

[droppinbottom]

the problem is the mass air flow sensor i learned this the other day when my 200sx did the same thing it would go to 2800 rpm and shut down just like it hit the rev limiter i had just put a injen ram air intake on and did not plug the mass air flow sensor in all the way. disconect the battery completly and replace sensor. problem solved

I would check your wires if they are new I would check them. Get a ohms meter and make sure they are a .003 or lower. if that is not it check your fuel filter, MAF sensor, ignition module " i cant spell" egr valve.