Hi I swapped in a1995 4.9l into a 1997 F350 4X4 that originally had a 5.8l and an E4OD tranny. I have the new engine all in and hooked up, the donor truck had a manual tranny so I found a pcm from a 1993 F150 with a 4.9l and E4OD tranny. I got the engine wiring harness with the motor, no MAF sensor. I am now in the process of getting it running but so far no luck, looks like a no spark condition so I am starting to diagnose all the related parts, have I done anything wrong with my parts selection with this swap?

 

Before I get the why didn't I stay with the 5.8l I want the 4.9l I am not hauling loads or trailers very much, I bought the whole truck for $400 minus the original engine. I do not want to stop at every gas station I pass and the 4.9l is admittedly one of the best engines ever and will last a long time if taken care of, I want to get this working. Oh I should also say that in my state this vehicle doesn't need to pass emissions so I removed the air injection and no cat.

 

In an F350 the 4.9 won't do any better on gas than the 5.8, but that's besides the point now. I see one problem right away with the engine wiring, that F350 was not MAF so the chassis portion from the block connector back to the PCM is missing a lot of wires you need. So your options are an I6 engine harness for a 92+ SD motor(same block connector) or if you happen to have the original V8 engine harness you could make that work, just take all the tape and loom off and connect up everything except 1 injector connector from each bank(chop those off later once you know you ave the right ones), and then tape it all up again.

 

Hi no the harness is correct as my 1997 F350 is not Cal emissions so the original 5.8l did not have a MAF sensor because it is over 8500 GVW and NOT OBD II. On the highway at 65 in OD the 4.9l will most definitely be better on gas than the V-8 I also am running an electric fan.

 

People think there is a significant weight difference from an F150 to an F350 it is only the unsprung weight that matters. In an empty unloaded truck of the same vintage and configuration i.e. regular cab long bed are the rolling mass is not that significant but most people do not have an F350 unless they need the load capacity, I like the old school solid front axle and manual locking hubs. One thing is for certain the 4.9 is a better choice than a 5.0

 

I reversed your message about wiring harness, the 1995 4.9l I used did not have a MAF sensor it was an early production.

 

Well once you get it running report back on the fuel milage, I suspect you won't do any better than the 15mpg I know a 5.8 can get. There is a hugh difference in curb weight between a 1/2 ton 2wd reg cab and a 1-ton 4x4 with the same body, and that will impact fuel milage. You will probably have to see this for yourself to believe it but that truck weighs every bit of 5500lbs empty whereas the 1/2 ton 2wd was only 4300lbs. And the F350 also has deeper gears than all those 1/2 ton I6 truck got so the motor is gonna be turning more rpms than it would at the same speed in the 1/2 ton, so again more gas burned.


No spark suggest a problem with the PIP module inside the distributor or a wiring mixup, but as long as there isn't a TFI module on the dizzy it should be correct. To change the PIP module the distributor has to be completely dismantled so you may be better off just buying a complete reman unit.

 

Hi, thanks for the tip I suspected the PIP and am going to do some diagnostics. You cannot compare fuel from 2wd to a 4wd of course that would be the biggest weight difference. To be fair you must compare trucks that other than the GVW are as close as possible in configuration so 4wd to 4wd, from experience I had a 1978 F150 4X4 with a 300 six that got 19mpg highway and that was carbureted and back then they used heavy steel frame and all cast iron transfer case etc so I am pretty confident I can get 18mpg highway, I am under no delusions that I am creating a fuel sipping truck, just trying to make an full size 4X4 reasonably efficient.

 

I have another question, because the truck sat for a while until I installed the 4.9l engine it took a while for the fuel system to purge and start building pressure, if the regulator is not seeing the right pressure will that not let the engine fire? I also do not have the O2 sensor hooked up but figured that would not prevent it from starting, I am just trying to get it running right now and then work out the bugs with emission's later. I do have the EGR hooked up, as stated earlier no Cat or air pump both removed as they are not needed in my state. Just trying to make sure I have the systems needed for start up working.


Brian

 

That suggests a weak fuel pump and/or a restricted fuel filter which wouldn't be surprising for a vehicle that has sat for extended periods. There is a shrader valve on the fuel rail that is used to test fuel pressure, with the I6 you should be seeing upwards of 60psi within 2 primes of the pump and the pressure should hold, and this should happen regardless of any potential sensor issues since the computer simply turns the pump on or off it has no other control and does not control fuel pressure.

 

Hi , I have a gage with bleeder on the fuel rail and installed brand new filter during engine install. With dual tanks do they share one pump?

 

If the fuel pressure is low would that stop the engine from getting spark or that is a separate problem? I do not have a garage so I am outside and cannot work on it every night mostly just weekends

 

What pressure do you see?

No, separate pump in each tank.

 

Not related at all.

 

It took a little while to purge but the pressure starting coming up and last I looked it was a little over 40psi. When I turn on the key I can hear the pump run. I used the bleed feature to get most of the air out until it looked like nothing but gas at least up to the shreader valve, no gas showing on plugs so I am not sure if the rails are fully purged back to the return yet. When it did not start I pulled a plug to check for spark and did not see anything so I did not keep trying to crank it and that is where I am now. I bought a good spark tester and now I am going to make sure all the systems needed for a start are working i.e. coil, distributor, ICM, once I know that is good then I will look further into the fuel but seemed like the longer I kept trying to crank it over the pressure was building. The original lines were cut by the previous owner who removed the 5.8L for another project so I used the ones along with the 4.9L I installed and took them apart at the connection at the filter so everything was completely drained dry back to the tanks for around 6 months until I tried to start the engine last weekend. I figured it might take a bit to purge the new lines, maybe I am wrong and the pump is going bad but I tried both tanks and got same result in pressure. Nothing rarely ever goes smooth with these things but I will get it, thanks for the help so far I will keep you apprised of my progress. If you think of anything I am missing please let me know.


Brian