just got done fixing a squeal per my other thread. ended up being an exhaust manifold leak on the drivers side, cylinder 6.

now a new problem, rough idle and NO power. ramming the pedal through the firewall doesn't do anything! i'm doing good to make it up to 10 mph. it didn't run this way before i started this adventure, so i'm guessing that i screwed something up.

seems to start fine and idle great for the first few seconds (about 15), then starts idling rough. I think that there's a sensor somewhere sending a bad signal to the ECU, that's why it gets rough after it warms up. it used to rev up really fast when i opened the throttle by hand, and kick in the rev limiter almost immediately, now it takes 3-5 secs!

I have replaced alternator, PS pump, belt, idler pulley, camshaft synchronizer assy, coil pack, wires, and spark plugs.

I thought for sure that the cam sensor wasn't aligned correctly, so i've re-done it 3 times. the last time i just set it to TDC and slipped the alignment tool on to check it, lined up perfectly... also checked with o-scope, cam sensor sends signal between the 4 and 5 tooth on the crank sensor(using missing tooth as "0"). i'm absolutely certain that it was on the compression stroke, i removed the fan so that i could personally put my finger over the spark plug hole as i turned it over.

I've put three different sets of plugs in, the first were NGK iridium, the second two were autolite double plats. the new coil pack is a screamin' demon, and it didn't make any difference in the idle or power before or after changing it out, or with plugs at 0.060 (per their recommendation) or at the stock 0.046. stock 0.046 are on there now with a new set of NGK wires from napa and the demon coil.

this morning i checked fuel pressure, sitting around 40-50psi the entire time.

checked vacuum, running around 13"hg. tried removing/plugging all of the vacuum ports, no change in idle.

I'm wondering if i have a blockage in the exhaust, I have an exhaust back pressure gauge coming so that i can check that. i'm a little suspicious that an exhaust manifold leak could squeal like it did out of a gap in the gasket. every leak that i've head before has been a "tick tick tick" puffing sound.

I'm stumped, can you guys think of something else?

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2002 Ford Ranger XLT
3.0L Flex Fuel Engine, Automatic Transmission

 

Well put your hand at the exhaust pipe and see if you feel a lot of air moving if you dont you have found your prob!

 

I had the same issue on my ranger ended up being a blocked catalytic converter. Check you o2 sensors as they can mess up the catalytic converters thats what happen to mone

 

There are gasses flowing out of the tailpipe, but i don't know if there's a restriction causing backpressure. going to start pulling O2 sensors tommorow and hooking up a backpressure gauge. I cannot believe how many cats they put on this thing! 3+2!

I solved the rough idle problem though, found a disconnected hose at the EGR solenoid. Also redid the cam synchro using a borescope to figure out which of the marks on the pulley were right. On mine TDC was when the lettering "TDC" lined up with the crank position sensor(CKP), and the "0" was almost in line with the hash mark clockwise from the CKP on a little casting sticking out on the block.

Now it runs well at idle, but stumbles at WOT, and there is a whoshing shound in the intake and soot inside the throttle body. My bet is still on an exhaust clog, will find out tomorrow!

Thanks for the replies.

 

threaded the backflow gauge into the o2 sensor bung on the drivers side and it pegged. >15psi. dropped the Y-pipe to find that the first converter the engine sees in the drivers side was gone, only the two bands of steel wool material were there. so, second one in the pipe was completely clogged.

luckily it looks like the main catalytic converter is untouched, so i got away with just replacing the y-pipe. seems like a whole new truck now!

now just have to re-gap the plugs and install the underdrive pulley and escape TB that i snuck in on a parts order and i'll be happy... for a little while at least. after doing my research here I have dreams of headers, roller rockers and a tune, but i'll probably just start with an e-fan and a high-flow muffler.

Thanks guys.