1992 F150 5.8 E4OD

I just finished building a 5.8L in my 92 F150 and just can't get it to run right. It runs terribly and will not idle, I have to feather the throttle to keep it running. It smells strongly of fuel like its running rich and if I run it for too long it will make the headers glow hot. It backfires air out of the intake random and erratically too.

The modifications are:
-Fiveology racing mass air kit with a junkyard 95 MAF ecu
-24# injectors and matched PMAS maf-Summit k4400 cam and lifters
-Ebay gt40p aluminum heads
-1.6 Roller rockers-Shorty Headers-Full emissions delete
-9mm spark plug wires and MSD cap and rotor

So far the things that ive diagnosed and tried are as listed:
-Verified base timing with spout disconnected at 12° btdc-Verified strong spark
-Verified spark reaching cylinders
-Verified firing order from distributor
-Verified firing order at injectors and ecu
-Verified all 8 injectors were firing
-Fuel pressure around 30 psi (will probably try this again as the oreilly fuel pressure test kit wasnt reading reliably)
-Vacuum when running was a somewhat stable 18 inhg while running but it was difficult to tell because rpm was bouncing due to running conditions
-Verified all ecm pin locations and quality from fiveology kit
-Reset preload for all rockers at 1/2 turn past 0 lash-Compression was at 120-130 psi at all 8 cylinders
-Tried running the truck with and without the MAF sensor plugged in and there was no significant difference in running.
Some other notes
-I have yet to 100% verify the cam timing. I assembled it dot-to-dot and when I put it at tdc both valves seam closed on cylinder 1.
-I am unable to pull any codes from the ecu and I believe its due to the fact I have an LED in for the CEL light and it hasnt worked since. And as far as I know there has to be a functional CEL to pull codes.

I've been diagnosing this truck for over a week now to no avail and I've hit a roadblock I'm hoping someone here will have some helpful feedback. I included a video of the engine running.

Here's a video of the engine running

 

Have you double and triple checked that you got the distributor installed correctly? The spark plugs may all be firing, but are they firing when they need to be?

 

Backfiring tends to be the mixture is burning with the valve opened. Make certain the firing order of the ignition system matches the camshaft.

120-130 psi is fairly low compression [hot/warmed up engine].

 

Yep the firing orders match up i have the distributor set up for the 351/HO firing order which is what the cam has.

1-3-7-2-6-5-4-8

It is a fresh new build and the piston rings have not been broken in yet. Plus the engine inst usually up to operating temp as I run it only for a few minutes at a time.

 

So you have a 5.0L / E4OD PCM?

Since the computer is programmed for 19# injectors why did you choose 24# injectors?

That cam is listed as not compatible with the factory computer system. Is that why you tried a MAF conversion?

GT40P heads are iron so what heads did you actually install?
How did you perform the “full emissions delete”?

Gt40P heads have pedestal mount rocker arms so there is no rocker arm lash adjustment. The bolt is torqued to spec.

 

Is the ecm tuned for 24lb injectors?

 

How are you cooling the engine?

 

30 year old junkyard ECU? Are you sure it's good?

 

Quote:

-Fiveology racing mass air kit with a junkyard 95 MAF ecu

You PCM has to be modified. Why did you not use their PCM?

If the headers are glowing, it is most likely running lean.

You need to call their TECH LINE for advice.

 

Using eBay brand aluminum heads, did you do a leak check on the valves?

 

So many things....

This is a flat tappet cam & not a roller?

Don't know anything about Fiveology. Was there re-pinning involved?

Adding of injector wires?

No tuning, just plugged in & run?

 

Either the PCM has to be scaled for new injector size or that MAF meter. Tuning MAFs is weird, we used Pro M ones back in the stone age. There was another brand/style with different size sample tubes to deal with injector sizing.

Agreed, what heads did you buy? Ps also take a near impossible to find header now. I too would have seen if they actually sealed if ebay specials

 

I chose 24# to increase the power ceiling. The ecu doesnt need a tune for NA 24# injectors, it just needs a MAF thats calibrated for those injectors.

I didnt choose the MAF specifically to expand my options for cams, mostly for its improvements to mpgs and more capabilities for power adders, which allowed me to use that cam.

I used generic gt40 "style" aluminum heads. That use rocker studs which allowed me to use roller rockers which needed to he properly preloaded

The emissions delete was performed by capping off all unused vacuum ports, wiring in line resistors where needed, and capping off the egr ports. The Smog pump is still in pace but acts as an idler pulley pretty much. I had done the emissions delete a while before the engine build and it gave me no issues so I don't suspect anything in that regard is causing issues.

 

Stock fan setup with an aluminum radiator.

 

They did not have any in stock ECU's at the time but I was in touch with Brian from Fiveology and I bought an approved junkyard ECU. I also replaced the capacitors in the ECU.

I do think its likely its running lean, I'm thinking not all of the fuel is combusting for some reason or another because, like I said before, it smells strongly of fuel after running it.

I have been in touch with Fiveology troubleshooting my issues and they have been very helpful but I have not yet been able to get it to run correctly.