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1990 F150 4x4 wierdness. Need advice please.

I have a 1990 F-150 4x4 5.0L with 118K miles on it and E40D tranny. Had it parked for 7 months before I needed it for a camping trip on the 4th of July. The transmission seems to be having problems since I started it up. I noticed that it had a delay when selecting (D), so I checked the fluid level and had to add about 3 quarts to get it to the safe zone on the stick when hot and running. Before and after adding the ATF, here is a list of the problems I am having. The tranny was shifting fine when last driven, but the idle has been rough for 2 years now.

Symptoms:

Transmission will not upshift until engine is really revving. Say 35MPH in first then slams into 2nd. 2nd to third at about 70MPH and no OD engaging.

There is also no "drag" when I let off the gas from the drivetrain. It's like the tranny gets put into neutral when in any gear. I can then rev the engine back up the the matching tranny speed and I can accellerate fine.

If I start in 1 then manually switch to 2 then it shifts into 2nd fine. But 2 to 3(od) still needs excessive engine speeds to shift into 3rd.

Engine idle is very rough when starting cold. It will die if left unattended.

Once engine is warmed up though, idle is very high. Probably about

1500-2000RPMs.

If I shut off the engine when it's revving this high, it will NOT start. It cranks over fine, but will NOT start unless starting fluid is used into the air intake tubes. (lame, but saved my ass from being stranded at a gas station).

I pulled the battery overnight to clear the PCM etc, but it made no difference. I am not getting any check engine lights, but it does work when I start the truck.

I was told to replace the fuel filter as leaving the tanks empty most of the winter caused rust to form, and filling the tanks moved the rust to the fuel filter and restricting the flow of gas, causing the engine computer to freak out and causing the tranny not to up-shift properly.

Any ideas? I really hope my tranny isn't wanged. It was shifting great till I let it sit for the winter.

TIA!

Reply to
ECS
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Check all your vacuum lines. Much of this is vacuum controlled in that model year. If dry rotted or broken, it will cause bad idle, rough running, etc.

Reply to
Marlin Singer

The idle speed gives it away. You've got a huge vacuum leak. These trucks have a systemic problem where you usually get huge vacuum leaks between the upper and lower intake manifolds. Probably that's where the trouble is.

Reply to
Joe

I agree that this is the first place to look.

----------------- The SnoMan

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Reply to
SnoMan

Would that cause the latent shifting problem with the tranny too? As far as the vacuum leak- you mean between the air plenum and the intake manifold? Or between the intake manifold and the valley?

TIA

Reply to
ECS

Yes (regarding latent shifting). The transmission uses engine vacuum to sense throttle input, and aggregates this with the roadspeed indicator (governor or output shaft sensor) to determine when to shift. Typically, low vacuum tells the transmission that you've really got your foot into it, so it delays the upshift (tries to wring more acceleration per gear vs. economy per gear). In addition, low vacuum and low roadspeed makes the transmission think you're pulling something heavy or ascending a steep grade- yet another instance where you'll want to stay in a lower gear.

So in this case, the huge vaccum leak is confusing the transmission, and making the engine run like crap.

-phaeton

Reply to
phaeton

Yes and look for a leak in line going to tranny or a bad vacum modulator on tranny itself.

----------------- The SnoMan

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Reply to
SnoMan

I would look carefully at all the vacuum lines. You stated this sat for quite a while. Mice and squirrels love to chew on things like that.

Reply to
Marlin Singer

Between the two parts of the intake manifold. I guess you could say between the plenum and the intake manifold. There's a big gasket in there with 8 holes in it. When you take the manifold apart you'll see where a big chunk of it got sucked into the motor (probably).

Reply to
Joe

you can spray some wd40 around the manifold and when it finds the vacuum leak, the engine will rev up. this will narrow it down so you can see the bad place or even fill it with a good sealer that will harden and stop the leak for awhle. old john

Hello, ECS! You wrote on Mon, 10 Jul 2006 10:56:20 -0500:

E> SnoMan wrote: ??>> On Sat, 8 Jul 2006 23:44:12 -0400, "Joe" snipped-for-privacy@dontspam.net wrote: ??>>

??>>> The idle speed gives it away. You've got a huge vacuum leak. These ??>>> trucks have a systemic problem where you usually get huge vacuum ??>>> leaks between the upper and lower intake manifolds. Probably that's ??>>> where the trouble is. ??>>

??>> I agree that this is the first place to look. ??>> ----------------- ??>> The SnoMan ??>>

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E> Would that cause the latent shifting problem with the tranny too? As E> far as the vacuum leak- you mean between the air plenum and the intake E> manifold? Or between the intake manifold and the valley?

With best regards, snipped-for-privacy@comcast.net. E-mail: snipped-for-privacy@comcast.net

Reply to
ajeeperman

Ok, after more troubleshooting, here is what I found. When the engine is doing it's high RPM idling and I pull the control cable to the IAC the engine will shut down. Something is telling the engine to rev that high I believe. If I did have a massive vacuum leak, wouldn't pulling the IAC have no effect on it then? Any ideas?

Reply to
ECS

The IAC also add fuel as well it bypass for idle control and when you pull it this is lost. YOu need to find vacum leak between engine and tranny or if modulator on tranny is bad because it wiull shift exactly like your is when there is a problem in these circuits or devices.

----------------- The SnoMan

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Reply to
SnoMan

Okey. I will pursue the leak some more than. I had a visit from a neighbor yesterday who suggested pulling the IAC.

Now all I need to do is locate my missing shop manual for this truck. Last time I used it was for the waterpump fiasco a few years ago. Suppose I gotta clean the garage then. crap...

Reply to
ECS

I couldn't remember if it was WD-40 or starting fluid. ;-)

You can also rent a vaccum gauge from most parts stores too, if you want a second opinion to what everyone says here.

Reply to
phaeton

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