Hello,
I have a 93 F150 and am pulling Code 41 out of my ECM. My symptons are missing under load, stalling from idle to accelarating transistion. Just overall runs bad. It has the 5.0 engine and automatic. If anyone can help I would greatly appreciate it.
Thanks In Advance,

 

I had been chasing a 41 code on my 1988 F250 for 4 months. I had pretty much the symptoms you descibe - lean misfire. In my case the injectors (or some of them) were bad. I had them refurbished and they still went bad. I have 185,000 on my truck. Finally, after replacing the injectors, (I took the intakes off 4 times) the 41 code left.

You have to see if the fuel pressure is correct and maintaining pressure. Obviously the fuel pump and the filter have to be good. You can't have any unmetered air leaks either.

 

Thats really not what I wanted to hear but kind of makes since. I had a fuel induction done I while ago and noticed absolutely no differnece in running. Which is very uncommon since every time I done the induction I always noticed some difference.
Anyway is the ohm test on the injectors a valid way to check them? If so what is the reading I am suppose to see?

 

What do you mean by "I had it done"? Do you mean you had them cleaned/flushed? How many miles on the injectors?

Mine tested fine 14.5 ohms each and they clicked nicely when I put a 9 volt battery on the connector. They still were bad.

I would have a mechanic test to see if the pulse to the injectors is about 4 to 5 mil-seconds. Check all the other fuel related stuff and then decide.

 

Fuel induction cleaning is what I mean. As far as the onm test my experiance and what I heard of is very inaccurate & not precise. Was hoping for another form of troubleshooting. The truck has 180000 miles and am most likely just going to gamble and say they are no good just hate that method of repair is all.

 

Have a peek at this. Two dealerships gave up on mine exhibiting similar symptoms, because their little mouse and keyboards couldn't find the problems (especiallly since dealerships no longer keep OBDI testing equipment). A vaccum gauge helped me find this. The EEC NEVER threw a code unless I disconnected something to check and see if the EEC was actually still monitoring it.



It's a common problem on the 5.0, because you have a pretty heavy tall intake on top of something that's got a lot of vibration with a pretty small footprint at the sealing surface. When you put the plenum back on, make sure that you don't tighten the support brace until the intake is torqued properly. Then, when you do tighten the brace, make sure you don't put any stress on the plenum. Look at the other photos in my gallery about the leaking plenum, too. Like the other poster said, I didn't replace my injectors, but I did clean them. (135K when the problem showed up) Clean the throttle body and IAC, replace the plenum gasket, TB gasket, IAC gasket. All those gaskets come in a top-end kit from Felpro. Don't remember the part number for the kit, though.

Then, when you're done with that, make ABSOLUTELY certain that the plug wires are routed correctly. Make sure #5 and #6 stay between #7 and #8 as long as possible. Your 5.0 will have the 15426378 firing order. It's hard to do this and keep them looking neat, but neat is a lot less important than elimination of cross-fire. If #7 and #8 get close, you'll get cross-fire on those two cylinders, and some horrible missing and pinging. Most of the pinging and detonation will show up under acceleration or load (climbing a hill), and especially at higher RPM. Make sure you're running Motorcraft or Autolite plugs as recommended on the underhood sticker. Stay away from gimmicky sooper dooper spark plugs. Make sure you're running Motorcraft 8mm or 9mm wires. The Ford TFI will EAT anything else. I had a set of MSD 9mm racing wires, and Bosch Platinum II's. Both were shot in 5000 miles. Park the truck in a dark place, start it, and look for any arcing from the ignition. Quickest way to test an ignition system's integrity. If there's a bad wire, or leaky coil, you'll see it. If it's inside the dizzy, well, that's a little harder to see. Normally, it shows up as black spider-web looking traces inside the cap though. Safest bet, get a good quality cap and rotor, preferrably with copper electrodes. I do like the MSD cap/rotor set. They're red and look good on the engine too. I've had no problems with those either. Just the wires.

Now, after you've done the plenum fix, and ignition tune-up, one more little step. You'll probably want to reset the KAM tables by disconnecting the battery for a minimum of about 15 minutes. Hey, take it loose when you start to pull the plenum. It'll be done when you're done with the plenum. Your truck will have learned some really bad habits if it's an intake leak. Let it learn new habits. You'll probably see slightly reduced mileage/efficiency for the first 100 miles or so, but you'll definitely know when it's figured out what's going on. It's really neat to hear the ECM learning on the first start too.

 

Well started today on checking a few things out to find my problem. First was going to remove the EGR valve and check make sure everyhting is clean. Well of course the EGR valve broke off in the pipe. No this required me taking of the plentum to get the rest of the pipe off to straighten it out. So the plentum gasket was in good shape.
So now I replaced the plentum gasket and of course the EGR valve and it still misses when under a light load. Also wants to stall if you transistion from idle to slow. Starting to have a feeling I am chasing multiple problems.
My next question is would spark plugs already be bad at 25000 miles. This would be a first for me but this ignition system I know is very picky about certain things. Never seen another vehicle that would have a crossfire condition with any brand new plug wires before. I can testify that this one does though (Been there).

 

You pulled the codes wrong. A 1993 truck will have three digit codes, not two digit codes.

 

i think 93 has 3 digit codes also.

are you doing paper clip or a reader?

this is where a reader surpasses the paper clip.

 

1994 was the last year that some trucks had the two-digit codes.

If has an AOD or C6 Transmission with MFI and a MAP then will have the two-digit code.

 

but some in 93 do have the 3 digit also?

 

My 93 uses 3 digit codes.

 

Yes and even trucks before 92 with the E4OD transmission and cars back in the 80's with SFI & MAF had three digit codes.

 

this code stuff makes me dizzy.

 

The codes where puleed with a Snap reader. Will have to try it again and see what comes up since they where cleared yesterday.