Hey all,

95 F-150 with the 4.9L, 5-speed.

I've gotten her all back together after a timing gear swap. I took her on a little trip to a customer's yesterday via the interstate. She ran well. For a while.

Then, she started bucking and losing power while in OD. I downshifted and she did better, but not great. If I kept it under 55 in 4th gear, she ran like she ought to.

On the way back, I got gas and switched to the front tank. The problems disappeared. So long as I was on the front tank, she ran well. The instant I switched to rear tank, she started bucking again.

Today, I had her stall on me a time or two. When I crank her back up, it sounds... demanding, almost as though there's a low battery. But only after a stall. Otherwise, she cranks just fine.

She idles around 1100rpm.

Last night, I ensured my vacuum lines were routed correctly after I pulled a bunch of codes.

I pulled these codes:

KOEO: 327, 522
CM: 122, 172, 211, 327, 332, 542
KOER: 311, 213, 327, 411, 167

However, once I got all the vacuum stuff straightened, she stopped throwing codes, but will still buck at low rpm.

I'm going to have to take off the timing cover again because I can hear the gear tapping the cover at low rpm. Once I get that taken care of, I'll put a timing light to her.

My question is, could this be due to a cracked EGR tube? The valve does actuate when I raise the rpm, but I'm concerned I may have cracked it at one point.

Also, in the event this is a fuel issue, I've replaced both tanks and pumps, along with the filter. I checked the fuel pressure a bit ago and she was normal.

Could this be the result of a PIP sensor in the distributor?

Any info you can provide would be great. She's starting to **** me off because I've put a bunch of time and money into this "free" truck. Every time I think I have her fixed, some other little gremlin crops up.

As always, thanks for the help. She's very close to being finished!

 

Under light throttle conditions EGR is applied so if the tube is cracked it can act as a "vacuum leak" aka..unmetered air into the intake.

 

Well, after pressing the timing gear further on, I've elminated the bucking at lower rpm.

What I traded for, however, is there is a power loss right around 1,500-2,000 rpm in every gear. It feels as though an invisible hand grabs the bumper.

I just don't think the truck is making the power it should.

My EGR tube is intact. She times at 10 degrees. She idles pretty well, but still around 1,100 rpm. At times she'll idle at 800. She's smooth as glass at that point.

Any thoughts on what's afoot? I'll check fuel pressure tomorrow, but as my pumps have less than 500 miles on them, I can't imagine they've gone bad. I guess I'll buy another fuel filter just in case, as I can't remember if I changed that before or after I put in new tanks.

Anything else I should check?