I've burned the #4 plug 4 times this year and I think I need to do something to the fuel system. I just don't think I'm getting enough fuel to that last cylinder. I have 55lb injectors already and a set of fuel rails. Most of the problem seems to be when I spray nitrous and also when I'm driving fats down the freeway.

I priced the fittings and making the line myself to include the adapters and regulator and filter is around $900. That is using the factory intank pump where I have twin 255lph pumps and using the fuel line as a return line. Prices don't include two Y blocks that I need...These are summit prices...

AEI-12301 Straight through design, flows 1,200 psi, 10 micron element, fuel filter... $79.95 $79.95

AEI-12601 Fuel Filter Element, 10 Micron Paper, Use w/ AEI-12301 Filter Assmembly $14.95 $14.95

AEI-13101 Universal, billet aluminum, adjustable 30 to 70 psi pressure, -10 AN inlet, -6AN return, 1/8 in. NPT... $135.95 $135.95

EAR-005 Plumbing Tool, Vise Jaws, 5" Wide, Aluminum $14.99 $14.99

EAR-300108 -8 AN straight, blue and red anodized Auto-Fit hose end ... $6.95 $55.60

EAR-300110 -10 AN straight, blue and red anodized Auto-Fit hose end ... $8.50 $34.00

EAR-318008 -8 AN 150 degree bent tube, blue and red anodized Auto-Fit hose end ... $21.95 $43.90

EAR-320008 -8 AN, 20 ft., braided stainless steel Auto-Flex hose ... $119.95 $119.95

EAR-320010 -10 AN, 20 ft., braided stainless steel Auto-Flex hose ... $135.95 $135.95

EAR-915106 -6 AN blue, straight female AN swivel coupling ... $5.25 $5.25

EAR-916107 Fitting, Adapter, Straight AN Swivel to Male NPT-8 AN to 1/4 NPT, Alum, Blue, Ea $8.50 $17.00

EAR-983410 Fitting, Adapter, Bulkhead Tee -10 AN, Aluminum, Blue, Each $15.99 B/O $15.99

EAR-984406 Fitting, Adapter, 45 Degree Hose Barb to NPT 3/8 to 1/4`` NPT, Alum, Blue, Each $15.69 $31.38

EAR-9892108 -10 AN female, -8 AN male, blue anodized, aluminum flare reducer ... $10.75 $21.50

EAR-991002 1/4 in. NPT, blue, female coupling, pipe thread to pipe thread adapter ... $2.95 $5.90

EAR-991912 -8 AN to -6 AN blue, male AN to AN union reducer ... $5.25 $5.25

EAR-992410 -10 AN blue bulkhead nut ... $3.25 $6.50


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Sub Total: $744.01

 

When I made up my lines I used hard line 1/2 in feed and 3/8 return.Pulled all the factory lines out and bent the new ones CLOSE to the same.Just omiting some of the sharper bends.Looks almost stock and works great.Going that way is cheaper and safer than using the braided line.since it can flex and vibrate on something and rub thru.Takes alittle longer but I feel that it is well worth the effort.Stan

 

Is that sewer pipe PVC or galvanized?

 

Probably bamboo. Stan is Old School.

 

Its gonna be a beatch if you find out you don't have a fuel flow problem and that you actually have an air flow problem in the intake manifold.

I'm not saying thats the case, but if you already have larger fuel rails then that should have slowed the fuel flow in the line enough to feed that number 4 injector.

Could be your getting the same fuel to all cylinders but the air flow is not equal ??
Dale

 

Bamboo.I am not that modern yet! But seriously i did that since it was down[from the engine fire]and I had the line laying around.PLUS I did not want to have another fire.Especailly when you are running 150+.So now I have 1 less worry and have a fuel system cap of well over 1200 hp with no problems.Stan

 

I have not installed the larger fuel rails yet.

 

Do you think fuel is the source of the problem? You should be able to run mid 10's(+/-600hp) with upgraded fuel pumps and injectors being your only mods. What is your FP at WOT? I am seeing 60psi with my new chip. I am using the stock fuel rails for now. The shot might be taking you over the edge, as I haven't used my nitrous yet.

 

I really don't know what the problem is.
I was running good air fuel #'s earlier this year with just the 55's and Walbro 255's. There are a couple of other things to consider. I had my wideband O2 on bank 2. I switched it to bank 1 recently. So I may of always had the problem and not known it. I have burned the #4 plug 4 times since April. It could be air flow, but since the #4 plug is last to get fuel I'm leaning toward fuel starvation in that cylinder. It happened last week with no nitrous...
I put in new Walbro pumps on Monday and noticed no change. My autometer fuel pressure gauge is low by about 4psi. I used a pressure tester on the schrader valve. I changed the filter a couple of times also. I hit over 60 psi with the boost a pump at 18psi.
Maybe the stock regulator isn't working, but wouldn't that lower my fuel pressure?
Anyway, all of the parts are ordered and I should have this done next week sometime. I don't think bigger lines could hurt and I really don't want a fuel cell in the bed of the truck.

 

I take it you have tested or replaced the injector for #4?

Mark

 

I haven't did that. I have removed the 55's a couple of times and replaced them with the 42's. It is a long shot that the same injector wound up in the exact same cylinder each time. I was also thinking the 55's might be taking out too much fuel and by the time the fuel gets to the #4 maybe there isn't much left in some situations. I don't know know how all of that works...

 

Len, youre definately running out of volume if youre burning up the #4 plug. Sounds like one of your fuel pumps just isnt pushing the volume it claims. I know youre running dual 255's but i would step up to dual 325's. Its much cheaper then this new fuel system you want to build and will most likely never take advantage of.

 

Well, just to be sure I'm going to do the line. It could be the Walbros just don't have the volume I need, but others use them...then again other people are getting along fine with stock lines, fuel injectors, etc...???
It isn't like I'm burning a plug every day. I've driven around 12K miles since April so it is a plug every 3K miles on average.

 

That's still not acceptable frying a plug every 3K or so. You can go dual 325's and also throw in an inline pump. You will have more volume then you will ever need at that point. Just trying to help you save some $$.

 

I wonder if it's not the WOT runs you are leaning on. It could be pulling too much boost on tip in. For instance, when you are in overdrive cruising up a hill and the boost gauge is at 9psi and you barely have your foot in it. Due to the extra load and not pulling enough timing out, mine will ping. My truck used to do that and I'm pretty sure that's how I slowly burned a plug. If I burn a plug during a WOT run, I'm usually backfiring and missing right away. But street driving can slowly destroy a plug if you are pinging just once in a while. It's hard to hear too when you are cruising due to the exhaust and radio. Might be a long shot, but that's my experience w/ lots of boost on these trucks.