I've tried 2 different widebands and had them one on each side and both on the same side and get the same results no matter where they are installed.

Fuel trims are very close to perfect and just bounce + or - a little. This is for idle and cruising and light acceleration. All of which the A/F does just fine. But, am I wrong, or doesn't the computer ignore fuel trims at WOT and just reference the MAF flow and load

 

So the truck is fine anytime except at WOT?

Do you have rails? How have you routed the fuel lines through the rails?

 

No aftermarket rails; I have used both stock L rails and some 97~98 F150 rails with an aeromotive adj regulator. Currently have the adj rail setup on the truck because it's been the only halfass way of making the A/F come within reason.

Another note about the situation; with the adj regulator set to a base FP of 44(39 didn't work) I was able to get the A/F to match the tune when I was running a ported heads/cams/6# lower eaton truck. BUT; the drivers side was still a good bit richer than the passenger side.

It seems the more power I try to make(currently have the KB on top of the heads/cams built motor) the leaner it wants to get on that side. Like there is a fuel supply problem, BUT I see over 60 pounds of FP.

 

And yes the truck holds 14.7~14.8 A/F idling, cruising down the road about as nice as you can get. Tip in and it does a very slight lean(high 14's to very low 15's A/F)jump but instantly comes back down. Then when you get more aggressive with the throttle the A/F gets richer. At this point I see mid to low 13's on the lean side while seeing good into the 12's and dropping on the rich side. More gas you give it(not going WOT) the A/F continues to drop, but still has the difference side to side. Then if you pin it WOT the A/F will jump lean and not recover unless you lift. Or, if it's a run where it's not a really lean condition(say about 12.1~12.2) and you stay in it it will finally drop into the 11's where it should be after it shifts into 3rd gear. Does about the same from a stop or role, but from a stop it has traction problems so you can't get a good 1st and part of 2nd gear reading. But, it's actually not bad bad spinning.

And yes it will do different things different times you go WOT.

 

Just in from playing with it some more...... It brought the boost down; havn't looked at the boost guage because busy watching A/F, but should be in the 14~15 range.

That helped the A/F a little, but still lean. For the hell of it I brought the 48 base pressure I had down to 42 and ran it; the lean got worse. So, I brought it up to 52 base and it got a lot better till WOT(could go almost to the floor and it would be great looking) With the lower base FP it would be lean during part throttle.

With the base FP I see just over 60 FP when I am in the safer A/F, but it is flucuating a little bit(pound or two) but this doesn't add up taking the 52 base under 12~14 boost I should be seeing almost 65#'s correct?

I also tried running a jumper wire in the Hi/Lo relay place and what's strange is it didn't change the FP much if any.......

I also before I started it(cold) cycled the key to prime about 10 or so times and started it watching the exhaust. I saw no black or blue or any form of smoke so I would say the injectors are leaking down.

Looks like I'll order another set of pumps and drop the tank.

Sal; got any 255 pumps in stock?

 

Initially I saw that you have 60 psi FP at WOT so if it's lean you need to bump the maf transfer. But then you said you bypassed the high/low relay and saw no difference in fuel pressure. Are you sure you jumped it right? You jump the #30 battery terminal to the #87A terminal instead of the #87 like most relays. The high/low doesn't use #87. Reason I ask is because jumping that should have put you at near 60 psi and it shouldn't have run at idle very well, if at all without re-doing the maf transfer to compensate. Or are you re-doing it every time you bump the pressure? Just going from 30 to 52 should have given you fits without re-tuning.

Jody

 

It changes NOTHING about the idle or anything by moving the FP up and down. That's what's got me dumbfounded! I mean I had it as high as 57#'s at idle and it was sitting there bumping off 14.7 A/F without a problem. Only thing changing FP does its make the A/F when almost and at WOT get richer and leaner.

I really really really think I have a pump problem. Either a bad pump(what I think) or a cracked hose, crushed "Y" fitting, or something. I got a lead on some pumps to try locally; maybe it will work out.

 

Well I was running open loop (no computer compensation) when I tried that and it wouldn't even run. But in closed loop the trims can pull 25% so it would still run. Hadn't thought of that when I typed. I had to change my maf transfer about 22% or so to compensate for the extra pressure; that's withing the limits of the computer so you could still have seen 14.7:1 a/f, but the trims would have shown what was going on.

Have you tried bumping the maf in the 700+ range for wot? I mean what a/f are you seeing and what do you want? I know you know this, but commanding 11.8:1 at wot does nothing if the maf transfer isn't adjusted to get you there.



I had the pumps installed on mine with the engine and they crushed the "Y' fitting by having the clamp right on the end of the "Y". One pump couldn't pump anything basically, but it showed by only going to 35 psi at wot.



Jody

 

Well; I didn't watch the trims, but still it should have been wacked out by that change atleast at first. Way back I jumper wired the hi/low and it did wack out the A/F at idle, but this was when all was doing ok.

No matter what it should be holding pressure.... So, I am gonna start with doing pumps. My question here is IF that "Y" fitting has a probem where can I get a replacement! I have been looking around a little as I would like to find a metal one, but can't find anything like it.

 

Get a hold of Promodlightning (Pete) I bought my set up from him. I think he has the Y fitting your looking for also.
Pete is a great guy and makes a kick azz fuel set up.

Peace,

Suavy