348 engine right bank not running

On my 95 F355 which has the 2.7 I had over the course of a year, my car go into limp home mode and tried everything--fuel pump and ignition relays, pumps, MAF etc, Turned out it was the cat ECU. Took 5 seconds to unplug it. Now I run with them umplugged and never had a problem. It would run on 4 cylinders. When my car went into limp home mode it did not throw a code.

 

On 348s the engine will run, no slow down light (or maybe that's because I took out those bulbs, or was that for the seat belts??? ), and the ECUs hold a silent code (meaning the CEL does not get illuminated).

 

Have you double checked your ground wires? The cable from the transmission to the frame, and the grounds on the wiring harness to the valve cover, or coolant cross over to the heads?

 

First get the car to run right. Prove that your problem is power to 30 by hot wiring power to start the car. Don't forget these cars have very poor fusebox. It is a multi-layer ribbon board with questionable solder joints and areas where too much transient current is flowing for the circuit which further destroys the fusebox.

 

As i stated previously, i think your fuse box is delaminating and killing power to one of your fuel pump relays. Until you get a new box you might buy a decent quality relay from an auto parts store( little black one with a mounting tab). Run power to the bus bar thats hot behind the fuse box, ground it and then run the output of your good pump relay to trigger the new one to come on and run your pump again. That way your pumps will come on and off together as they do with the stock circuit and you should be safe to go again.

 

If you do end up needing a fusebox, let me know. I have a spare I'll let got for a reasonable price after fixing another one.

 

Replied and sent you some thoughts and schematics that may help. Hope it helps!

 

My friends 1990 car had the exact same problem. We did everything suggested here. Finally took the coil pack from my car and swapped it. Fixed. Took about 4 months of tinkering around to figure it out.

 

Speaking of coil packs, I do believe porphy has some. If you need one or both drop him a pm.

 

Hotwire fuel pumps, one at a time. Listen with a dowel or screwdriver to the pump and your ear. Do the pumps sound different? Perhaps the 1-4 is running full bore? Sometimes the rubber fuel line on the pump will pop off, esp if they've been replaced with hoseclamps at some time. It's also common for the screen to become clogged with deteriorating rubber.

 

Man that was a pain. I remember that from the 358.

 

Had same issue last summer. Turns out fuel pump basket was clogged with a bunch a black crap. Replaced pump. Found the other pump also had a bunch of this black crap in the basket, as well. Seems that US gasoline attacks the black rubber liner that the actual fuel pump sits in.

 

Check the wiring connector that goes to the right bank crank sensor? The connectors get hit with road debris and dont appear to be that great to begin with. Could have a prong backed out or cut wire and no injectors firing on that side?

 

Change filter?

 

Maybe you fly Plugzit and I to Houston...stuff us full of Texas Bar-Be-Que and we will come fix it.

 

Why did you change the R pump? If the old one ran did you put a fuel pressure gauge at the fuel rail to determine if you have the correct pressure? Have you put a gauge to the fuel rail with the new pump? You are 110% sure the right is out not the left? Running starter fluid in a dead side with good spark is very noticeable like the car will idle perfect for a few seconds and you can run the car by continuous spray of the starter fluid then it will die when you stop. Did you do that? You statements about starter fluid sound nebulous and unsure.

Another default is possible connections problem. These electrical connections can be very finicky hence the invention of the gold kit or home brew Tin pin replacements. Sometimes with tired pins you have to bend the bejeezers out of them to make decent contact. The engineered on/off cycles according to Helms is something like 10! A somewhat weak electrical system can mimmick a fuel problem. That is why Ernie mentioned checking your grounds even though you profess this to be a fuel problem.

 

Still sounds like the bank is in limp mode (injectors not firing). Do both bank's cel's and slow down lights illuminate when you turn the key to run (all four should light up before you start the car)? Swap all electricals from one bank to the other bank over, engine ecu, cat ecu, cat temp sensor, maf, o2 sensor, coil etc. Everything. If the problem moves to the other bank, it's a faulty component and you can swap them one at a time until you find the bad one. If it doesn't switch sides, it's an electrical issue, either wiring or connector if you've swapped fuse boxes.

 

nope 348