2003 Ford Ranger - 3.0L Won't Rev Past 3000

[drwilson]

Hi. This ranger wont go past 3000 rpm, acts like hitting rev limiter.

Has new plugs, wires. good compression across all cylinders.

Where to start?

[brianp87]

what is the exhaust back pressure?

[Jeff @ Able Auto]

Also what is fuel pressure and flow? Is this free rev or in gear?

[drwilson]

backpressure 0 psi both banks, fuel pressure is 60psi at idle, 50 koeo. As for volume, i cannot say. Noticed engine vaccum less than 15 in/hg at idle. fuel injectors were replaced recently, as was fuel filter.

[fortknoxx]

maybe clogged cat?

[Jeff @ Able Auto]

Check fuel pressure at 3000 rpm. 15 inchs vacuum at idle is low. I have had cars that had presure but not enuff volume to run at higher rpm.

[ricmorin]

I agree with Jeff. 15 is too low. Find out why.

[a&mauto]

Scope your cam pos sensor on top of the synchronizer. I had one that did the same thing. Drove me nuts.

[drwilson]

The cam position sensor is working normal, we just tried a new one... not sure yet on engine vaccum issue. I noticed something else, fuel trim and o2 sensor readings are what outta wack. bank 1 averaging towards lean o2 reading, fuel trim in positive between 6-9%. bank 2 however is averaging 0.9v on o2, fuel trim keeps going negative, yet will just to shft2 +50%.

[steven kiser]

i've seen bent tail pipes cause issues. is it an immediate issue or does it take time to build up? if timing has jumped there's your issue.

[brianp87]

Id be looking for a vac leak

[drwilson]

no vac leak found at all. issue is immediate. exhaust all appeard ok. Best theory was jumped timing as well, jsut due to low vacuum <10inhg. but no way to tell now; cust was tired of truck anyway, sold it i guess. This one had me for a week. I was close to gettin er done but no cigaro..
Im glad its gone but dangit, such a let down for me personally, not to mention the shop. Thanks for the advice and tips!

[steven kiser]

thanks for keeping us updated.

[brianp87]

thanks for keeping us updated.

+1