93 running lean

[RonD]

Same pattern as head bolts, from center out, crisscrossing as you go

 

[rathr-b-cruisin]

well, got it all put back together with new injectors. and it freakin runs the same. when i first started it i was like wow that sounds great. then went to get some gas and guess what, chugging, have to floor it to get going then it hauls butt. this is starting to make me think of selling it. I put almost 300 bucks in it today and it's the same problem. it seems to act up when its warmed up more than cold. when cold i think it runs good. after it gets warmed up it starts acting up. like i get 1/2 way to work or 1/2 way home. or drive around a bit then thats when it starts.

New: plugs/wires, TPS, coil, injectors, intake gasket, MAF sensor, O2 sensors, exhaust, fuel filter, fuel pump (before i got it), tested the fuel pressure, replaced both coolant temp sensors, and probably something else i cant remember.

 

[rathr-b-cruisin]

power control module? how would you test that? when the battery went, i had to jump it and my son said that sparks were flying from the positive terminal? not sure if that would do anything. it would not start though we had to have the jumpers hooked up for 10 minutes to get it started.

 

[RonD]

Reads like you are chasing ghosts so it could be the EEC-IV (PCM)
Yes, voltage spikes can hurt the PCM, there are a few "do nots" now when using jumper cables when you have on-board computers.
First is "do not" have engine running when hooking up jumper cables, this causes a voltage spike from the alternator of the running engine when it "sees" the low voltage of the second battery, it can ramp up to 15+ volts, also bad for the alternator, lol.
Shut off jumper engine before removing cables

Unfortunately there is no way to test the PCM outside of reading the codes, which is a "sanity check" but doesn't really test all functions.
Removing it and opening it up will tell you if there have been any internal shorts or water intrusion.

Good info here if you want to test wires while it is hooked up: http://www.auto-diagnostics.info/ford_eec_iv

You can test voltages coming out of the PCM

 

[FloridaGrown]

Yes. If your truck is running Rich your cats will glow red hot like molten lava. I'd crank the truck up in the dark let it run and see if your cats are glowing.

 

[FloridaGrown]

another thing. I've had this problem with my bronco 2. It ran like water was in the tank. It sounds like the tfI. rare but could be. You drive it a few miles and it acts up. The tfI is on the back of the distributor it advances and retards the timing. They where susceptible to heat and would fail when the truck warmed up. just an idea.

 

[rathr-b-cruisin]

well i got home and i was going to take out the pcm to have it tested or at least look at it as i've seen posts where the back of the module was corroded. my wife comes out and says close the hood and take a break tonight you've been out here all week. I said ok i just want to put this back together then. so i put it together and took it for a ride. started off fine as usual but this time instead of bucking and chugging it lost power. before if i floored it it would take off. now if i floor it it loses power and sounds like just air rushing out the exhaust. Now i'm like crap, i'm taking this in. I have lost inspiration and just want this fixed. I think i'm taking her into a shop.

 

[FloridaGrown]

Do you have the inline fuel pump on your frame? I thought the stopped that in the 80s but if you have the inline fuel pump those are some of the symptoms.

 

[Andy D]

Take out the O2 sensor. That should relieve a plugged cat. If it runs better, then the cat matrix is plugged up. A new cat might help. The backfiring exhaust is raw fuel cooking off in the exhaust. If you have the original coil,put it back on. I wouldn't invest in a new cat until what ever is causing the cat to glow is fixed. After mkt ignition coils are iffy. You may have gotten one that was bad out of the box.

 

[rathr-b-cruisin]

i read a lot about the eec having bad caps in them. i took mine out to look at it and took the top off. i found these caps to be bad. I ordered an eec from rock auto. we'll see what happens. i'm sure these are bad. Not sure what they do haha.

 

[rathr-b-cruisin]

so this is the latest. I put in the new ecm today. it started right up and idled smooth. as soon as i took off i could tell a difference. felt pretty good. i can tell that when taking off and making a turn take it easy bcuz she'll turn over the tires. then the intermittent miss started again. it starts to miss or choke out, then if you floor it, it picks up again. engine light came on so i go home and check. got codes 173 , 176 and 177.

then i made sure everything was on. checked the fuel pressure. turn the key on the pressure is @40, start the truck and it drops to 30. haynes manual says key on engine off should be 35-45 psi, which it is. and running it should be 25-35 psi, which it is. then unplugging the vacuum hose it should be 35-45 and it is 40 psi. everything looks good there.

so i go for another ride and it rides fine for a while, then it chugs and i would call it a miss except i get no miss codes. it just chugs and feels rough, then if you give it the gas it picks up and runs fine for a while and keeps doing this.

I'm sure the new ECM has made a difference. however i'm kinda where i was before again.

after i got back i checked the codes again and now i have 172,173,176,177

 

[rathr-b-cruisin]

would you believe that the O2 sensors were cross connected?! it is running great. i've put over 50 miles on it and the cel has not come on once.

 

[huh?]

i enjoy happy endings.......






however.....






i'm really curious how you figured out the O2 sensors?????????????????








also, thanks for the follow up

 

[enjr44]

I am curious how you could tell they were cross-connected!!! And, of course, how they got that way!!!

 

[rathr-b-cruisin]

no idea how it happened. when i had the new exhaust front pipe installed i gave him 2 new sensors so he would not have to mess around with pulling out the old ones. I would blame it on him, but the truck ran bad before it went in. the connectors in the wiring harness were not mounted on the brackets like they probably should have been. they were just hanging down at the back of the engine. you can take the harness and flip flop the end of it. there is plenty of slack to plug them in backwards. my cousin came over and we messed around trying to figure this out. he is a painter at a Ford collision shop so there are mechanics there. he was telling some of them about how when i pulled the plugs they looked the opposite of what the computer was saying. i had codes bank 2 lean, and the plugs showed rich, bank 1 rich and the plugs looked lean. and one of the mechanics said maybe the sensors are backwards and laughed about it. so we got a wiring diagram and followed the wire colors and holy crap! sensor 2 was hooked up to bank 1. the truck is running great!

Big thanks to everyone that helped to work this thing out.