Ok, here's the skinny, this truck has moods, and i cant figure out what the deal is here. When I start it up 1/2 of the time when its cold, it acts perfect. Lotta HP, no funny idle or anything, runs great. the other 1/2 of the time, and seems to be more so when its already warmed up, the idle is 'lopey' down to 500 or so, then up to 1100, back down to 525, then 1075.. that kind of pattern until it levels it self out at 750 with a slight ping, or kills itself all together. Additionally i've noticed when its lopey, if i hit the gas at the right moment, it will 'behave' and sit right at 750. I've timed it several times, have new plugs / wires, new o2 sensor, air tube was leaking at the cat, welded that closed. And when i tried to run the codes on it, I came up with a 44. Ran the test a second time, and nothing, 11's all around. Does this sound like an EGR going out? or is there something in the AIR system that could be doing this that i'm over looking? nothing seems to be loose as far as vac hoses go. But i'm running outta ideas. Any help would be appreciated. Thanks

'89 F-150 4.9l 5-speed HD, and 211,000 miles

 

Could be the EGR, or the EGR controller. Do you have a vac gauge?

Off topic...what do you mean by the fivespeed HD?

Adrianspeeder

 

try cleaning the idle air control valve. we have some of those trucks on the farm and they will build up carbon in the iac and have a lopedy idle. take the valve off and clean it with spray carb cleaner and they go back idling normal.
hope this works.

 

Well I have the HD Tranny, out of the 2 that are available in 89. Cant rememer the name... I want to say e4od ? I dont know its early, lol I do remember it tho from doing the clutch a while ago. Had 20 bolts if i remember correctly. And nope, i sure dont have a vac gauage, and where is the EGR controller at? Not too sure i've seen that.

 

Hey, didnt even think about the IAC. Had some issues with that on my SHO. Looks like this one would be a bit easier to take off, than the SHO too. Another quick question I have is about the 'fiberglass' gear on the bottom of my distribuitor. Cant say i've been that deep into this engine, but I've been told this is what they put on these trucks. Could that provide enough 'slack' to be rich on Monday, lean on Tuesday. ? just a thought. And how bad / hard are those to replace? Thanks

 

The E40D is an automatic. The M50D is the light duty 5 speed. The HD 5 speeds started with ZF.


Check for wear in the gears (cam/crank/distributor) by removing the distributor cap and rocking the engine back and forth with a breaker bar on the crank bolt. See how much play there is.

 

lol wow, it was really early wasnt it.. From what i remember my clutch was 1/2 an inch bigger in diameter than the other, and was told that i had the heavy duty one by a friend. I have no sticker on the inside of the door, so its hard to tell a lot of things with this truck. The tag on the rear diff is hard to make out too. Guess thats what happens when you drive around in a state with snow / ice / salt for 16 years. At any rate, how much play should there be? I would think just enough to make it 'hop' the other direction right? This morning I turned the timing backwards just a hair, maybe a degree or too, lost a lil power in the middle, but it wasnt nearly as 'strange' at start up. I had avanced it a little a few weeks ago to see if I noticed any mileage difference, and that part was obvious. On the highway I was down to 13 or so, and before I had nearly 18, and nearly 20 with a nice tailwind. Additionally how much difference could a slightly higher octane fuel have on such an issue? Any thoughts? and thanks again.

 

There were two five speed manuals ford used. The M5OD is what came in the 150s and can be quickly be identified by ribs on the side that go verticle and horizontal. The ZF5 is the heavy duty five speed used in the 250s+. Can be quickly identified with ribs that go diagional. Is that what you have? I would be suprised.

Adrianspeeder

 

That's interesting. The clutch disc used in the M50D w/ 4.9L and 5.0L was 11", but the disc used with the 5.8L was 11.6", at least according to Ford. But when I replaced the clutch in my '95 4.9L/M50D, it had the larger disc too.

 

But the only five speed stick with the 351 was the ZF5 in the 250 and 350.

Adrianspeeder

 

That's interesting too. I don't have the '89 specs in front of me, just the '95 specs. I guess things changed quite a bit between the two. In '95 the M50D was the cheap tranny, then they had two ZF tranny's, a light duty and a heavy duty. Both the M50D and the LD ZF could be ordered in a 150, 250, 350, or Bronco w/ a 4.9L, 5.0L, or 5.8L. The HD ZF was available in the 250 & 350, with either a 460 or a diesel. The M50D & LD ZF had either an 11" or 11.5" disc, while the HD ZF had a 12.25" disc.

What's really odd is all of my 1989 service manuals list E150's, F150's and Bronco's with a 351 and a 5 speed, and list the specs for both the M50D and ZF S5-42.