I have a 1994 F150 4X4 with automatic E4OD tranny. When I take off from stop with light throttle the truck seems fine but when I start off with heavy throttle it seems to lose power. When the rpms raise up they seem to drop back a little then back up just before it changes gears. Anyone know what would cause this?

 

check your atf is it low? Does it smell burnt? If that seems OK then change your fuel filter(s), their cheap if it keeps up lets us know.

 

Is it RPM related? Does the truck's engine lose RPM, or is the RPM ever-increasing while it seems you go slow all of a sudden?

 

Pull the codes.

 

The RPMS drop back without slackening the throttle. Here's what I have done so far....new trans fluid and filter, full tune up, absolutely no codes coming up, cleaned intake, replaced the sensor on the rear end (was told that was the problem...not), cleaned and checked every wire harness connector for corrosion. I also noticed that when the truck starts to run loagy that the oil pressure switch goes to low and fluxuates there until I put on the throttle again. Replaced oil pressure switch and wire connector....didn't fix the problem. I am at my wits end. Thinking about selling the truck. Does anyone know what is going on? The local FORD dealer doesn't. HELP!

 

Yes, I think I can help.

If you RPM's drop after getting on it from a stop, you have the symptoms of what few Ford garages recognize (but then some of them came up with this fix, too). I suggest that you may need to make a restrictor, or blocking, plate for the EGR.

The EGR's on these trucks were designed for the 400 cubic inch engines. Ford decided to use it after blocking off one of the two EGR holes and they called it a day, but this turned out to not work for many of us as our engines got more miles on them.

(The old Ford Garage fix was to stuff tin foil down the EGR's pipe, but a metal plate between the EGR and its mount is more reliable.)

It seems that most auto tranny truck drivers don't notice it, but some do. Manual tranny drivers have a much harder time with it.

Search this Inline Six forum for EGR AND RESTRICTOR (or PLATE), and you'll find plenty of info on it.

It takes a metal plate, a drill, and two new EGR gaskets (cheap at FOrd dealerships) to do it.

Buy the gaskets, and use one as a template for the bolt holes you'll need to drill. Unbolt the EGR, pull it (or pry it) apart, totally clean off the old EGR Gasket from the EGR and the plenum mount, then place a gasket, the plate, and the other gasket inline between the EGR and the plenum, and carefully bolt it together.

It's up to you - some of us drill one 1/8" hole to restrict the flow, and some of us block it off entirely. I chose to restrict, and now wish I had just blocked it.

It worked for me (or the truck would have been sold - too many stalls from stopsigns with a manual tranny and 2.73 gears (and I can drive anything with a clutch, as can many of the others around here, so it isn't us)). You and I both know these trucks didn't run like that from the factory, or no-one would have bought them.

Best,

 

MY EGR is leaking. I can tell because when I spray carb cleaner at it, my idle changes. Isn't it supposed to be closed at idle? If I put on a restrictor plate wouldnt I also want to plug up the exhaust tube going to the EGR to keep exhaust from escaping from the leaky valve?

 

Are you sure that blocking off my egr won't hurt my engine or auto trans? Have you ever heard tell of this causing premature lock-up in the trans?

 

Just a little added information.....I replaced the EGR valve about 3 monthe ago (aftermarket not dealer) but made no difference except to erase the code for insuficcent EGR vacumn.

 

guitar_god2003, replacing the EGR wouldn't have an effect on your overall plenum vacuum - there would still be too much EGR gas flowing into the plenum.

If you want to be sure, first check your engine for a vacuum leak. None found? Next, I did my bit of typing (above), and I'm going to leave the rest to you. There are too many posts on this subject for me to go on to prove to you one way or another. That's what the 'SEARCH' function of this site is for.

You may find a little of the info in the other forums, but this specific EGR problem is an Inline Six problem, so I'd limit your search to here.

(edit: hmm... can we not search the old forums from the new SEARCH tool anymore?! But some of these may help:

https://www.ford-trucks.com/dcforum/...mID9/2110.html

https://www.ford-trucks.com/dcforum/...mID9/1875.html

https://www.ford-trucks.com/dcforum/...mID9/1559.html )

okla_stampede, just where is your EGR leaking? If you sprayed it, you could have closed a vacuum leak from the vacuum line that goes to the EGR (easily fixable of course), or you could have hit an area before the EGR (the Exhaust Gas pipe that feeds it), or you could have hit the EGR gasket area (maybe it's just your gasket?).

Yes, if you do block it off, seal it up with two new gaksets, and it is still leaking, you will want to fix the leak for safety's sake (assuming it is an exhaust leak). If it is a vacuum leak at the EGR, you may be able to just plug the vacuum line that runs to it, but you may get an error-code and a check engine light in the cab to come on.

That's the rub - to avoid getting error codes and engine lights, sooner or later we have to buy a new EGR valve, but for our engines to run properly we have to block them off (even the new ones) anyway. Go figure.

Best,

 

GammaDriver, I blocked off the EGR like you said but it didn't make any difference to the problem that I am having. When the truck is warmed up, and I start off from stop with a heavy throttle, then when it hits second gear that's when it goes loagy. Like I said it seems to crap out around the same time that the oil pressure guage acts up (might not be related). What could cause this?

 

Second gear only?! I thought you had problems at the beginning of each gear (especially first).

(Still, what type of plate did you use, and which gasket? did you clean off the old one? Or was there an old one left to clean?)

What mileage does the truck have?

Interestingly enough, your oil pressure guage really can't indicate too much - it's an 'enough pressure/not enough pressure' guage that really acts as a fancy idiot light. If it is going down, you either really do have serious pressure problems, your RPM's are really, really dropping, or you have some electrical problem there. Any chance some wire (regular or ignition) is moving, then shorting out, when your truck shifts hard into second? (This could be due to the forces of acceleration, or the forces of the engine twisting over in its mounts.)

I believe Ford stopped putting actual working oil pressure guages in the trucks in about 1988 or 1991.

It would be nice if you had an RPM guage to hook up to it to see just how low the RPM's are really getting during your second gear. (Not first nor third, eh?)

This is all in the hopes, of course, that your tranny isn't messed up. For it to do it in only one gear is ominous.

Best,

 

GammaDriver..lets recap. When the truck is cold, the transmission shifts perfect with no loagyness...lots of power. When the truck warms up, and I apply a moderate throttle, first gear is fine, hits second gear (not hard) it seems to go into some sort of lock-up or loagy (rpms drop), and the same thing through the rest of the gears. I checked all the postings you mentioned about the EGR/RESTRICTOR and made on just like it said to do but it didn't change a thing. I have replaced everything that I was told so far that it could be but to no avail. Is it possible that the computer could be causing all of my trouble?

 

I suppose the computer could be it.

You recapped, but you left out mileage.

If it is a warm vs. cold thing, it could be a closed-loop/open-loop problem, but I would expect to see that in first gear as well. Yet that isn't happening.

Have you tried running it throught the gears with the overdrive button on and off? Not sure what that would do...

But I'm at a loss. You do need to look into what is making your oil pressure switch let the guage go down.

Hmm, I wonder if you have the speedo problem some others have had? When you do get up to speed, does your needle jump a lot?

 

Did you ever pull the codes? Have you tested any of the sensors as described in the Haynes manual? It may be as simple as a bad ECT or MAP. The codes will probably tell you, but you need a multimeter to confirm before you buy parts.

You can swap your non-tach cluster for one with a tachometer with almost no effort. It's totally plugNplay. You can find tach clusters in the classifieds, on eBay, or in your local junkyards.This site shows how to R&R it.

If you search, you'll find several threads that tell how to convert your oil pressure idiot gauge to a real working gauge for only a few bucks.
Here's most of what you need to know about your speedometer.