Injectors Vs Fuel Pressure

**Roadknee** · 08-05-2014

Either install it in the left header and extend the harness, or install an O2 bung in the right header or Y-pipe just downstream of the connection to the right header. That will take less time than trying to tune it out. Your existing bung in the Y-pipe will be a great location for a wide band if you ever install one.

**brian617** · 08-06-2014

Originally Posted by Roadknee

Have you noticed any low rpm, low map surging, like 1,500 rpm in park? It can happen sometimes with the narrowband O2 in that location due to increased transport delay.

Thats actually real close to the factory location for the heated o2 in his truck. It was the earlier trucks and manual versions later years that had the single wire in the left manifold.

**Roadknee** · 08-06-2014

That is true. I think the headers and aftermarket pipe have quite a bit more volume compared to exhaust manifolds and the small factory Y-pipe. Also, the VE at part throttle, low rpm with performance cams is less compared to a stock cam so it takes quite a bit of time for the O2 sensor to see a change. I've reduced the surge some on a similar application by messing with fuel trim parameters, but have not completely done away with it. It's not my truck, so I don't get a lot of time with it. I suspect it would be easier to just relocate the O2. That said, part of me would like to see BLG355 tune it out so I could at least learn how it's done.

**BLG355** · 08-08-2014

Originally Posted by Roadknee

That said, part of me would like to see BLG355 tune it out so I could at least learn how it's done.

Well, after looking at this more closely, the left manifold is out of the question for right now, I'm not sure there is enough room for the sensor with the floor pan heat shield right there, it's sort of tight. but I am going to try tuning it and seeing what happens. The worst thing is I am going to have to weld a new bung in, no big deal. I did modify the current bung, I attached a picture of an O2 sensor I took, and put a line showing where it sat in the pipe before I cut the bung down. it was about 5/8" tall. I did run the truck after making some slight adjustments, the cold idle is getting more inline I feel and the only major issues I am going to tackle is the part throttle surging, which isn't quiet as bad now while driving, but after coasting and going into the throttle a little it is really bad. but the fuel map is all over the place, I decided to start over since I put headers on an changed fuel pressure with larger injectors and such.

Once thing I did notice that I had in another thread, I am still down to 90kpa by 5300rpm at WOT on the pedal, it's the same with the lid normal or flipped. maybe it's a candidate for a larger bore throttle body, since I opened the intake up I can consider that now. According to cfm calculators, it needs anywhere from 470-540cfm, 470 being stock and 540 being performance built. I'm not sure they a stock TB flows but I'm probably maxed out. I may bore one I have here and either buy or make some new butterflies for it and see how that works.

I am also taking the roller rockers off and trying a set of roller tip rockers. I had these one an engine in the past and they were silent, especially compared to these full rollers. I am still getting what seems to be excessive knock count, even though it isn't pulling any timing, the knock counts are still high. I have a set of from pro mag stainless roller rockers, the there quiet too but they need guide plates and the shaft rockers definitely won't fit these heads. So I am hoping roller tips and ball fulcrum will work better for less noise.

I will post again once I do more testing and tuning and get some parts swapped out.

BLG

**BLG355** · 08-15-2014

is it normal to have a spread in range like this?

range.JPG

BWT, I swapped out the roller rockers for roller tip rockers, knock counts went from 3000 to 30 over a 10 minute run. sometimes more, sometimes less, but overall, knock counts are way lower. Also, the surging is still present under no load conditions, but seems to have improved greatly while driving. Each time I run a log and mess with the fuel table, it seems to get better. I'm just not sure about some of the cells, I have such a large spread, I guess once I get it in the middle it will be ok.

BLG

**BLG355** · 08-18-2014

Originally Posted by Roadknee

That is true. I think the headers and aftermarket pipe have quite a bit more volume compared to exhaust manifolds and the small factory Y-pipe. Also, the VE at part throttle, low rpm with performance cams is less compared to a stock cam so it takes quite a bit of time for the O2 sensor to see a change. I've reduced the surge some on a similar application by messing with fuel trim parameters, but have not completely done away with it. It's not my truck, so I don't get a lot of time with it. I suspect it would be easier to just relocate the O2. That said, part of me would like to see BLG355 tune it out so I could at least learn how it's done.

Do you think adding a catalytic converter could help with the surging? I am emissions exempt, but i have been thinking about installing a high flow catalytic converter anyways.

**brian617** · 08-18-2014

Did you ever get a wideband hooked up Barry?

**BLG355** · 08-18-2014

Originally Posted by brian617

Did you ever get a wideband hooked up Barry?

I have not. I wanted to get the manifold glowing issue under control before I attempted anything else. I have a bung I need to weld in, I figured I'd weld it in while doing the converter perhaps. As far as the wide band O2, is there any one setup or brand that works best? I want to get one but I'm not sure what to get.

BLG

**brian617** · 08-19-2014

I just went with a cheap AEM, seems to be holding up well.

**BLG355** · 08-29-2014

I have been playing around with some minor changes, the surging never went away until tonight. So, I decided since back in June I installed the Napa injectors to try to solve another issue I though I might be having, that it was time to put the 5.7 injectors back in since it ran the best with those. I upped the fuel pressure to 22psi, I probably should have made it 23 or maybe 24 but it's ok for right now. It goes a little lean, like 800mv at WOT, but it's only at 84% IDC at 5200rpms so it should be fine for now, once I adjust the tables it will come up. I will up it again when I upgrade to a larger bore throttle body. I had a old problem come back, with is the rolling idle, mainly when it is cold. but that may be because its lean in cold loop. But the surging appears to be gone. completely gone. I ran a log, about 15 minutes long, and I didn't notice a surge once. The engine seems so much more responsive with the 5.7 injectors. So I guess it's back to the VE tables again and trying some other things out, it is running pretty good right now so it shouldn't take much. I am also running Brian617's timing table he posted earlier in the thread, it's not pulling any timing so I'm glad that issue is behind me too. It is a little more aggressive than the one I got from Mark, so far knock counts are very low.

BLG

**brian617** · 08-30-2014

I've reworked my maps a bit more trying to get the timing to come in faster at WOT. I'll post my latest .bin when I get back to my lap top. Be great if you tried it and gave me some feedback to see if I'm improving or not LOL!

**brian617** · 08-30-2014

This is my latest .bin, remember it's $0E. Criticism constructive or destructive welcomed. Anyone welcomed to copy and paste any part you like!

**Roadknee** · 08-30-2014

Originally Posted by brian617

This is my latest .bin, remember it's $0E. Criticism constructive or destructive welcomed. Anyone welcomed to copy and paste any part you like!

Brian - are you running any initial timing, or is that table what you see at the crank?

**brian617** · 08-30-2014

10* Intial, but it's accounted for in my .bin, so my engine sees what is on map, or that's what I presume lol.

**Roadknee** · 08-30-2014

Originally Posted by brian617

10* Intial, but it's accounted for in my .bin, so my engine sees what is on map, or that's what I presume lol.

You're correct. You have initial timing set to 10 in your bin so the PCM will add what is shown in your table less initial.

I like your BIN. I spent some time looking at it and you've worked with a lot of the parameters.

I'm curious if you've tried any more ignition timing. I'd think your engine could use 4° more across the map unless the chambers of those heads are ultra efficient. Also, how high do you rev the motor? Does it pull pretty clean through 5k? Have you tuned with a WB at all?