Surges at 3000 rpm, lack of power uphill and most any other time...

[alamogeorge]

2002 3.0L FFV 130K miles.

Driving through the hill country one day and I noticed a lack of power going up the hills. I mean I had to put flashers on and let other vehicles pass. I pulled over at the next gas station and found the pcv hose in bad shape. It was a generic replacement hose with no elbow. Check Engine light came on and set a code of P0171 "lean right bank." I replaced the pcv and hose and reset the code. Performance didn't improve but the code never came back.

Changed air filter, which was super dirty, no change.

Cleaned MAF sensor....no change.

When I got home I found that, with the truck in Park, when I rev to 3000 rpm it shakes and surges. When I get to 3k rpm on the highway it just lacks power.

Next, I replaced fuel filter and that didn't change anything.

CEL now flashes when driving at highway speeds and set a code yesterday...I think it was P0306....anyway it was "misfire detected cylinder 6." Time to replace plugs anyway so I did that and no change. Reset code and didn't come back. BTW with the 306 it also set 2 codes of P0000. What does that mean?

I've checked all the hoses and don't see anything obvious.

A friend told me to spray wd40 around the throttle body while truck is surging/shaking and see if it levels out....it doesn't.

Next I was going to check the fuel pressure....

Any ideas?

[masterbrenden]

what year truck we talking about here

[alamogeorge]

Sorry....2002 3.0L FFV 130,000 miles.

[masterbrenden]

that does have a rev limiter at 3000 in park and neutral btw...i think that is the bad year for valve but i am unsure. i don't have ff and mine is a bit older aswell.... the others on here could pipe in and give you more info.... i have just hear that the early 2000's had valve issues and seen it on a friend 04 ranger 3.0l.

[alamogeorge]

So, it's normal to act that way when I rev it? I guess I never revved it in the driveway until I had problems with power on the highway and hills.

[AgPete139]

I'm beginning to wonder if your coil pack is bad...

[alamogeorge]

I was gonna check the coil last night but dinner was ready. I think I'll do that today.

[BeaterMan]

I had this issue with my old 99 3.0 ffv 5speed. I kept getting bank lean and missfire codes ect. I hooked an oscilloscope up to everything, spark plugs, coil, ect. and found that 4 of 6 injectors had bad patterns. I replaced all 6 injectors and the truck ran great after that. No more hiccuping or surging at all and codes never came back. Mite not be your problem but gives ya another place to look.
Good luck

[alamogeorge]

Update: I didn't get to check the coil due to a busy weekend. I tried to drive to work today and had almost no power whereas before it was only noticable uphill and accelerating on the highway. I had to turn around and ride the bike to work...brrrr.

It threw a code of P0171 again (lean right bank) and P0175 (rich left bank). It also had 4 P0000 codes.

[alamogeorge]

Checked the coil. At least I think I did... Got another P0171 and P0175

Checked the pairs (next each other, right?) all read 10.8 k. Compared to the new one at autozone that read 10.6 k. Haynes manual says 13-15k but what do they know. It matched the new one and that's good enough for me.

The primary at the connector was a different story. They all read 0. Said to measure from the center post (there are 4 posts! which is center??) to an outer one. Either way, they were zero across the board.

I did the voltage check on the MAF sensor and that came out good.

I had an issue with the pcv elbow hose. I replaced that and also had an issue with the connecting hose from the elbow to the pcv. I couldn't locate a replacement but I modified it and it has a nice tight seal.

Didn't have access to a fuel pressure guage nor the $150 deposit to borrow one from autozone but I did depress the valve and it shot out like a rocket so I'm assuming that I have good fuel pressure.

Can't find any obvious vacuum leaks... Funny thing is that I just payed it off and was so happy that it was running great and I didn't have a payment.

[AgPete139]

If it's a lean & rich banks codes, then I suspect your problem may lie form the headgaskets. Have you tried the WD40/gas trick to see if your idle changes?

Sometimes, unmetered air gets in after the MAF and causes vacuum surges and idling problems.

[alamogeorge]

Yes. I've sprayed wd40 all over the place. I fixed a leak at the pcv connector but I think I'll give it another try.

Replaced fuel pump and that didn't change anything.

I did find something interesting. I pulled each plug wire off one at a time. The ones on the driver's side make very little difference to the idle if at all.