My dad owns a 1995 F150 XLT 5.8L. He's had it for many years, but kept it around the acreage for most of those years driving it a handful of times a year when he was back in town from his other homesteads riding horses pulled by his newer truck. It sat outside and always had mice in it. Recently, he drove it up because it wasn't running right and I found mice had built a nest under the intake plenum on the passenger side bank of injectors. I blew it out with air and realized they'd eaten one plug wire off completely and nibbled on the other two badly and even into the IAC wiring connector a bit two. I took of the plenum, rewired in a donor injector to the loom, coated the other wires in brush on insulator, lots of coats, and then electrical taped and friction taped them all up. Put it all back together and it would start, but still ran like crap with a major hesitation between idle and 2000rpms. It was so gutless that it even wouldn't go up the driveway incline from a stop in first gear. I had to take a run at it in first and still floor it to get it to inch up the driveway. My dad never did any basic maintenance on it besides oil. So I replaced the badly corroded cap and rotor. Still no change. I tested the first plug on the drivers side with a light and it is weakly flashing the inline test light. It won't even start now that the temp has dropped to 20 degrees, it seems like it barely even fires on occasion the colder it gets. The plug wires were stuck to the rusty plugs on the drivers side and I pulled them all and wire wheeled them clean to test it out before I'd even bought a new cap, wires, and plugs. That didnt help either. I plan on changing out the plugs and wires this weekend when its warmer and I have time. I pulled code 213 and 172 while running it before I changed the cap and rotor, but I'd cleaned them up with a wire brush first. I tried starting it with the MAP unplugged, then the O2 unplugged, and the IAC unplugged. No start when cold. I can hear the pump come on in the tank every time. Tonight I'm getting the old coil checked out just in case and I'm buying a Harbor Freight fuel pressure gauge tester to check the rail pressure. I have a fuel filter, but that's going to get changed this weekend when I again have time and the sun is out so I don't freeze my *** off on the creeper. I'm wondering if running it with those shorted wires caused some shorts in the system. I can't find any vacuum leaks when I had it running. I bought a couple of cans of starting fluid and sprayed a bunch down the disconnected brake booster line and it didn't help it start at all. I did it 4 times with no improvement whatsoever. I'm gradually eliminating things instead of throwing parts at it, but this is stumping me. This is kind of reminding me of the problem I had in my chevy TBI system that I put on my 76 Jeep CJ7. It stopped starting one day after sitting for a month. Couldn't start it in the cold. Next spring it started up, but had no power/idled erratically/no acceleration and after a few days or so of working on it realized that it had a bad ignition module. Replaced that and it ran like a champ! This likely happened when I was cobbling the system together from the junkyard setup I got and might have shorted some wires will getting it all setup in my Jeep. So am I being biased by my own experience or does all this sounding like the Ford ignition module has had the same thing happen to it due to the shorts in the wires caused by the mouse nest?

 

So today I changed out the drivers side plugs, wires, and the coil wire. The old plugs that I took out last week and cleaned were now coated in black carbon residue. No oil, just dry carbon. It was much warmer today, so it fired better but still would barely run and idle around 600rpms while I held the gas pedal to the floor. If I let off of it, it would die. I had to use a few shots of starter fluid into the throttle body plates to get it to start it, held the pedal to the floor, and after a few minutes or so, it gradually came up above 1000rpms. I kept feathering the pedal back until it got up to around 2000rpms and eventually warmed up enough to start with just the key. The temp gauge still said cold. After about 20 minutes of this the temp sender hit the middle operating temp. I then let it idle, checked the exhaust, it was clear and strong. I crawled underneath and looked at the cat, it seemed to be fine, no glowing. Took it for a test drive, still no power whatsoever, chugging and wanting to die a little under load. Got it back, switched through both tanks of gas, no change. It revved up in idle much better when finally warm, but still sounded like it had an occasional miss. I'd checked the fuel pressure on the drivers side rail before I'd started it and it was getting around 40psi. So after it was warmed up, I ran the self test to get codes while it was running. I did it all right, reving above 2000rpms for 2 minutes before restarting and connecting the jumper. Got codes 632, 536, 538, and 172. So I didn't hit the brake in time, no biggie, Traction control, who cares, that leaves me with a lean bank on #1 from O2 senser, just like I'd gotten before and the insufficient rvs during the Dynamic Test. It was too late to attempt the passenger side wires and plugs today, so that'll be tomorrow, but I doubt that's going to help much. Any thoughts? I've got fuel, plugs are firing, it just doesn't run or start worth a **** cold right now. I did try spraying the starting fluid around the engine and vacuum hoses and intake, but nothing happened while it was running. I doubt I have a vacuum leak. I'm wondering if it could be a bad Coolant sensor or perhaps the TPS is fried from the previous mouse chewing. I just cant understand how it barely starts or runs with the pedal firmly to the floor. Too much gas when it's cold?

 

Trying to start it with the pedal to the floor shuts the injectors off. This is by design to clear a flooded engine, just like we used to do with carburetors.

 

I read where you have a fuel filter, but not where you changed it. I also read where you had 40 psi before you started it, it's heard to tell about the volume and pressure with the engine running.

I would be inclined to change the fuel filter especially beings the truck sat so much. But don't expect that job to be easy, I read you need a special tool and it is still a great challenge.

I also read the injectors will get gummed up when a vehicle sets too much. Maybe that is your problem. Anyway good luck with it.

 

thanks! i'm hoping that when I change the spark plugs on the pastor side of the engine things get a lot better but I'm not holding my breath . I would've done it the other day but realize that with these coolant lines running right in front of the spark plugs this is going to probably take me three or four times longer than it would on the other side and likely I'll have to remove the tire on the passenger side to get to some of them . at least now it seems to be starting right up and idling but still has the same no power problem . and the fuel rail had 40 psi when I turn on the ignition before I started it and while running . I do plan on running at least one or two bottles of fuel injector cleaner through it at some point because I know they are probably a little gummy. Im trying to be logical and not throw parts at it. when I bought my 99 prism it had a hard time starting it's cold and Woodfell the plugs up I did a tuneup on it that help for a little while and then it had the same problems and . I bought a new airflow sensor for it thinking that was the problem because I had read about other people having that problem that fit the symptoms . Well it turned out to be gummed up EGR valve that I cleaned up and reinstalled and then had to remove and clean my brand-new plugs because they have become so file they didn't work well . I'm just hoping new plugs and wires on the passenger side fix this, but I have a suspicion that it's something else and the spark plugs are taking the brunt of it .

 

mine sat for years and after changes of fuel and gas cleanup it is running much better. You might consider the fuel is not so fresh..just a thought in addition to the needed parts.

 

Ok. We finally got a break in the weather so I've had time to work on it outside . I finally completed the full tuneup by getting the spark plugs changed on the passenger side . Looks like the plugs hadn't ever been changed as they were 40 to 50% off in gap from wear. Did the feel filter is well which was a little dirty but not too awfully bad . No change. I used some short pieces a vacuum line between the spark plug wire and cap to test for a dead cylinder. Thought I'd only found two underneath the Plenum so I decide to order two rebuilt injectors and swap them out in case they were bad because I didn't want to have to take about Outagamie and I heard the injector working closest to that side with a mechanics stethoscope. thought I'd only found two underneath the Plenum so I decide to order two rebuilt injectors and swap them out in case they were bad because I didn't want to have to take it off again and I heard the injector working closest to the front on that side with a mechanics stethoscope. Tested the old injectors with the intake off with the multi meter . They appear good and I had power going to all the injectors on the passenger side. I dug through the wiring on those two dead injectors and rewired them with mechanical splices just in case . Put it all back together and still had the same problem . Well I had the warm weather I performed another test on the cylinders and discovered I had missed two more dead cylinders. It was cold and dark out when I first checked it so I think I may have not quite notice so cylinders were dead and shorted the cylinder next to it in the dark without noticing. So now I definitely know I have one bank of injectors not firing . Remove the PCM and inspected ever any physical damage of which there was none . Looked great. So now it can only be one of two things which is a really bad short in the wiring loom where I can't see it or the PCM has gone bad ion that injector bank and just doesn't show any physical damage. Considering that the mice only ate the wires underneath the Plenum where they made the nest and that they'd totally consumed the insulation on several inches of the wiring for the fuel injectors and in one case eaten it back completely 6 inches including the wires, I have to believe that when we tried to started up and move it the injector wires shorted out something in the PCM but didn't burn anything on the circuit board . What do you guys think?

 

Finally remove the inner fender and remove the PCM from the firewall . Did a resistance check on The injector grounds and then manually grounded the injector banks with the PCM removed and the ignition on to power the injectors . The missing bank fired. The PCM showed no visible damage whatsoever and wasn't throwing any injector error codes . I decided to order a used PCM for 50 bucks as this is the last possible problem it could be. As soon as I plugged the replacement OCM in and it started up and ran perfectly. So the only parts I bought that I didn't need to were the two rebuilt injectors that were located under the intake Plenum . I made a mistake was trying to do the dead cylinder test on the distributor cap and putting the two vacuum lines on the plugs next to each other. Since the missing bank of for all next week so there when I shorted it out I didn't notice the other two being shorted out in the dark. It was dark and cold and I wasn't focusing properly so that's on me . The day I went to remove and replace the two injectors it was very warm out and I got a chance to do a little bit more diagnosing and take my time in the light of day . It's all good though and everything else everyplace is part of the badly needed tuneup so now the truck runs like a striped *** ape! So if anyone ever has a wiring sure problem on any feel injector on their V8 F150, keep in mind that it is very likely that you could have shorted out and injector bank on the PCM and it may not show any physical signs of damage once you remove it .