lacking power...

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tclndcrz

tclndcrz

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Beaufort SC
Could a manifold leak create a loss of power?

one of the trails i go to is 30 miles out and goes up and down inclines at highway speeds. i know my truck is not that poweful but i believe my truck has lost some power and i think it might be due to a manifold leak. the leak has been getting worse and worse and makes an odd whistle when going fast. sometimes the truck feels fine and other times really sluggish. i dont think it is old gas either.

thanks
-Thomas
 
Yup. A leaking manifold will make the mixture too lean and you will have a loss in power. The intermittent power loss feeling is caused probably by the heat of the manifold letting the gap either expand or contract.

The vac gague will make the inference a fact.
 
Is the power loss more apparent at higher speeds and higher RPMs? If so, you may want to check fro a restricted exhaust either in the form of a clogged cat, dented (crushed) pipe from wheeling, or even more common a failing bi-metal spring on the manifold flapper failing and leaving the flapper in the 'cold' position. If it is not higher speed or RPM related, and more just random, start looking at the carb.
 
no carb its fuel injected. i think its at higher speeds that i really feel the power loss but of course i dont think i have great power anyway.

clogged cat? i think this is very possible. i have a flowmaster 40 series and they are known to be kinda loud yet i can only really hear the exhaust when my ear is right by the exhaust

i had crushed my exhaust pipe so it was almost closed recently but i cut the exhaust off by 6 inches recently. no issues there

ive never heard of a manifold flapper. how can i check this?
 
Look into that exhaust, but also get a vacuum gauge to check the manifold vacuum. It should be around 16mmHG
 
I have similar problems with my 89-almost positive it's clogged cats. Not only are they original but I can smell them burning on hill climbs. Possible tranny filter, too?
Todd
 
The cat won't get hot if it's bad. Take the skid plate off with the engine running, warmed up by driving, & put your hand near the inlet & then the outlet of the cat. If the outlet's not noticeably hotter, you gotta dead cat.

You can also use a laser thermometer, but it needs to have a range over 500 degrees F.
 
Sorry to hijack. My exhaust has been smelling bad recently, and I have noticed a sluggish issue after cold starts. Could a failing smog pump cause the same (or similar) problems as a bad cat?
 
tom, you got that new tranny now right?? perhaps your kickdown cable etc. wasn't properly set when the rebuild was done?
 
zmontgomery said:
tom, you got that new tranny now right?? perhaps your kickdown cable etc. wasn't properly set when the rebuild was done?
Click to expand...

hey zack yeah i got the the tranny rebuilt but i was feeling the loss before hand. maybe i shook up the cats offroading. ive been doing that a ton lately. anyway i think im just gonna straight pipe the cats this weekend before i drive home next week. i will see how it feels. lemme know if you wanna have a beer or two thisweekend
 
pplkook said:
my suggestion is to go to the R-bar, Hauf, or the Scoop and drink till you can't remember....then head over to the kitty box (cats paw) and drink some more...:beer:


-Jack
/MSU EE grad
Click to expand...

fxxxin eh!! another montanan. im pretty sure the cruisers are multiplyin in bozeman. i have 4 friends at msu with cruisers and now someone else? what do you drive man? im sure ive seen it around town. offroad at all around here? ive got a good line up for trails in the fall if you want to come along with us. its usually 2 60s an 80 and a big red dodge

for sure with the drinks :beer:
 
Unfortunately the college days are behind me now...grad in 97. I live in Cali now, working, paying bills....savor the good days while you can!

Used to live on 8th st, near the Molly...man those were good times.

If you ever hit San Jose/SF give a shout

-Jack
 
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