Boss 302 Manifold Issues
- Thread starter 121AK
- Start date
Ya baby, lots of positive knock towards the top of your RPM rangeLooks like you're hitting +6 from 6500 until you let off the gas.
Thats a LOT of knock.... no wonder you so far down on power... i'd definitely say its bad fuel. or at least a big contributing factor. i cant look at it until i get home.
Wow this log looks crazy in livelink lol, your shits jacked up lol, on the initial WOT hit it adds timing up to -6 sub 3K which is normal on a base tune then its just chilling at 0 till 6K when it has two blips of +2 and then at 6500 all hell breaks loose and holds +6 till you let off at 6800ish, which is also super low for a boss to begin with but I imagine it would have just been knocking more if you continued. Man I think you have more issues than just fuel, usually bad fuel causes issues on the initial hit which yours adds timing.
since its easy, toss a socket on top the knock sensors, make sure they are tight.... could induce false knock. also make sure nothing is bouncing around in there.
Will do.
It’s worth noting my Boss 302 manifold came with a fuel rail and injectors. The previous owner had 20k miles less than my original so I used his.
I have an extra set of stock injectors I’m thinking about swapping out just to check that off the list.
Dont just tighten the knock sensors they have to be properly torqued.
177inch pounds. I have a torque wrench.
Mine came loose, and when your at a race, ripping the stock intake manifold out as fast as possible to try to make the qualifier, you dont use a torque wrench to tighten them.
i dont think a little more torque is going to hurt them. im not saying to go nuts but make sure they are not loose. I was getting false knock, and kept getting worse and worse and that was found to be my issue.
Nobody said that op is not currently at the track lol. Im just saying properly torquing them can save you alot of headache down the road. Im not sure how they respond to over torque but it could causue them to read improperly.
Got the torque wrench out. I loosened them up with a socket and then torqued them backed down. They did seem kinda loose when I first touched them.
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have a new data log? did the knock go away?
I’m still putting it back together. Got late last night and I called the quits. I’ll have a new datalog here soon.
your A/F ratioos are off bank to bank with the passenger side being quite a bit leaner, the STFT is trying to compensate but is unable to correct it. since you replaced the plugs already do a compression test with the motor warm. if that checks out try cleaning the injectors and swapping them bank to bank a relog to see if the problem moves. Your MAF lb/min shows 35 which indicates around 350hp. Also getting alot of knock in the upper RPM most likely due to running out of fuel.
Is that log on your nitrous tune? 18deg timing at 6k is way low for an n/a 93 tune.
Is that log on your nitrous tune? 18deg timing at 6k is way low for an n/a 93 tune.
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Yup, I'm an idiot. That was a nitrous datalog. Attached is a 3rd gear pull on the NA tune.
I attached a new datalog. Seems like lots of knock still.
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Lund finally got back to me and we made a discovery. Fueling from bank to bank on the WOT pull has over a 45% difference. Bank 2 shows a 25% rich correction and Bank 1 shows a 20% lean correct. They think it’s like the O2 sensors are swapped. I did mess with those when I removed my X-pipe a few weeks back. So this could explain it.
I remember hanging them on their respective sides when I took the x pipe off but maybe I damaged them or didn’t put them in back correctly.
I knew it had to be something I did as the car ran great before I did these mods.
I remember hanging them on their respective sides when I took the x pipe off but maybe I damaged them or didn’t put them in back correctly.
I knew it had to be something I did as the car ran great before I did these mods.
I wouldn't think that the O2's being swapped would make any difference. Now, if you have the pass side harness hooked to the drivers harness, and viceversa , well that could cause an issue. I just don't see how that would be possible. I could see them maybe being damaged during removal as being likely.
I removed the sensors and x pipe when I installed the blowfish trans bracket as it made things a bit easier.
What should my next step be here? Be a good idea just to order 2 new O2 sensors?
Anyone have other ideas? I'm going to order 2 new O2 sensors as they currently have about 84k miles on them and Lund suggested they could be the fault.
The tuner at Lund did not specify front or rear however when I installed the blowfish transmission bracket, I removed my X pipe to make installation a bit easier. When I did that, I removed the rear O2 sensors and temporarily hung them up. I swear I put them back but maybe I messed them up. I'm not sure.
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