I may be able to make it work if it comes to that. I already have a wideband sensor in my exhaust manifold. We'll cross that bridge when/if we get there.
Working out the kinks on the fresh build
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Alright, I just finished swapping injectors 3 and 4, I added an oil catch can between the PCV and intake manifold, and did the relearns. I let it idle for about 15-20 minutes now, no check engine lights yet. AFR has gone down from 14-15.5ish yesterday to about 12.5-13.5 right now. I’m about to take it for a ride to see what it does.
Edit: I want to note that there was a decent amount of oil at the bottom of the intake manifold. I’m hoping the two catch cans will prevent oil from being added to the air/fuel mixture.
Edit again: Just finished about a half hour trip mostly around 50 mph. Car seems to run smoother than before. Power at low RPM seems more consistent so I’m able to cruise or go up hills easier at high gears and low RPMs. Gas mileage seems better too for whatever reason. The highest I got this month up to this point was 27.2 mpg, and after resetting it went up from 0 to 28.6 mpg. A/F ratio at idle and all driving conditions seems to be much richer than before. No engine codes yet. It’s strange that swapping two fuel injectors could do all this, but I really don’t want to think about it too hard yet lol
Edit: I want to note that there was a decent amount of oil at the bottom of the intake manifold. I’m hoping the two catch cans will prevent oil from being added to the air/fuel mixture.
Edit again: Just finished about a half hour trip mostly around 50 mph. Car seems to run smoother than before. Power at low RPM seems more consistent so I’m able to cruise or go up hills easier at high gears and low RPMs. Gas mileage seems better too for whatever reason. The highest I got this month up to this point was 27.2 mpg, and after resetting it went up from 0 to 28.6 mpg. A/F ratio at idle and all driving conditions seems to be much richer than before. No engine codes yet. It’s strange that swapping two fuel injectors could do all this, but I really don’t want to think about it too hard yet lol
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I have to wonder if the PCV is bad...and if oil was coming in at quantities that favored the condition you had on #4.
I would hate to think the PCV was bad. The valve covers and PCV valves I had installed post engine swap were all brand new. When I was looking for vacuum leaks a couple weeks ago, the PCV and vent from the valve cover were routed to the same catch can to the intake pipe. I when I separated the PCV from the catch can and ran it back to the intake manifold, I connected it to the port on the Altima plenum behind intake runner #1, so I would think cylinder 1 should’ve been most affected by oil but the misfire remained on #4. The amount of oil seemed about equal on all intake runners when I was looking at it earlier today. The oil definitely wouldn’t help, but I don’t think it’s the main cause of my misfire.
I want to believe that the injector I swapped from 4 to 3 is flowing more fuel than the others. My narrowband O2 sensor going to the ECU is on exhaust runner #4, so the ECU should be adjusting A/F ratios based off the information from the MAF sensor and the cylinder #4 A/F. My wideband O2 sensor is lower on the manifold where the runners collect so it’s seeing the A/F ratio of all cylinders. What I believe is happening is that the injector I swapped from 4 to 3 is still flowing more fuel, but the ECU isn’t seeing it since it’s on cylinder 3 now. So the A/F ratio looks good and theres no misfire according to the ECU, but the wideband sees the richer A/F ratio from all cylinders collected.
I’m a little irritated by the inconsistency of the fuel injectors. There’s no check engine light anymore, but I don’t really want to leave them alone now that I know they aren’t right. I think I’ll get a brand new set instead of a remanufactured set this time, but I’m going to take some time to consider whether I should go stock size or upgrade for e85.
As for the coil pack issues, I want to believe that the fuel injector was spraying a large enough mass of fuel to make it difficult for the plugs on cylinder 4 to make spark. The extra resistance at the spark plug would put more load on the coil pack and “make it work harder,” pushing more current and wearing it out prematurely. High current and high temperatures (like the engine bay temps) kill the lifespan of electronics.
Edit: I’m going to email the 2JR guys and see what they think. I bought the injectors from them so maybe they can send me a good one, or give me advice on whether upgrading and going to e85 is a good idea.
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Well I have some vq37 injectors hint hint wink wink
What size are those?
I’ve been playing with fuel injector calculators a bit recently to try and feel out what size would be appropriate, but I honestly have no idea what power gain to expect after upgrading. Can Uprev data log duty cycle? If it can then I could see how close I am to pushing the current injectors to their limit with my current setup, take a guess at what power I’m at, and then figure out what injector size I need for increased power from there.
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VQ37 Injectors
Off loading them, was going to hold on to them for back up but clearly decided not to. $120 shipped for all 6, basically $20 each. Injector 2 (357) and 3 (356) Injector 1 (361), 2 (360), 3 (360) & 5 (364)
www.b15u.com
I don’t think those will be big enough. From what I’m reading, you have to increase fuel consumption by about 30~33% to make the same amount of power on e85 as gasoline. Then after advancing ignition timing and adding more fuel for more power, you end up needing even more flow.
VQ37 Injectors
Off loading them, was going to hold on to them for back up but clearly decided not to. $120 shipped for all 6, basically $20 each. Injector 2 (357) and 3 (356) Injector 1 (361), 2 (360), 3 (360) & 5 (364)
330cc x 33% = 108.9
330cc + 108.9 = 438.9
So I want to say that I need about 440cc injectors minimum to make the same power as the 330cc injectors are capable of, but then I still need a larger size depending on how much fuel consumption is necessary to make more power. It may not be much since I’m N/A so the only way I can use e85 to make more power (without rebuilding an engine or going FI) will be by advancing ignition timing.
I’m thinking about swapping my Altima plenum for a Rouge plenum, I’ve heard that those perform better and I should be able to find one in pull-a-part easy and cheap. I’m also thinking about upgrading to a 70mm throttle body.
2JR got back with me and advised me to go ahead and swap all 4 injectors. Here’s what they said about e85 and the throttle body idea;
“E85 and a larger TB are a no go in a QR25. Limited power gains, bad idle quality and a hunting idle. Also E85 is not consistent in quality and Uprev cannot compensate for ethanol percentages leading to very poor performance.”
They also just let me know that the Rouge plenums have clearance issues with the hood closing. I still want to grab one and test fit it, but my Altima plenum already has clearance issues with the Spec-V strut bar, so it may not work. If I like the Rouge plenum then I’ll probably go ahead and get 2JR’s throttle body spacer.
My plan is to order new fuel injectors from Rockauto. If all goes well then the car should be ready to tune by next week.
“E85 and a larger TB are a no go in a QR25. Limited power gains, bad idle quality and a hunting idle. Also E85 is not consistent in quality and Uprev cannot compensate for ethanol percentages leading to very poor performance.”
They also just let me know that the Rouge plenums have clearance issues with the hood closing. I still want to grab one and test fit it, but my Altima plenum already has clearance issues with the Spec-V strut bar, so it may not work. If I like the Rouge plenum then I’ll probably go ahead and get 2JR’s throttle body spacer.
My plan is to order new fuel injectors from Rockauto. If all goes well then the car should be ready to tune by next week.
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Not saying this item is still available from the forum member, just pointing out that there is Flex Fuel stuff available so this might give you a clue to getting e85 working despite 2JR comments. Worth investigating if you really want to do this.
www.b15u.com
E85 Setup Content Analyzer, Pressure Sensor &...
Hey guys, my part out continues, sold my ProEFI harness but still have my E85 equipment for sale. The following is for sale: Flex Fuel Sensor : $350 shipped (believe this thing was $600) ProEFI 150PSI Pressure Sensor : $125 shipped Zeitronix Ethanol Content Analyzer : $150 shipped Fuel...
www.b15u.com
I’m just going to leave it alone for now, I really just want to get the car closer to a finished state. It might be something I revisit down the road if I happen to take the car to a higher power level.Not saying this item is still available from the forum member, just pointing out that there is Flex Fuel stuff available so this might give you a clue to getting e85 working despite 2JR comments. Worth investigating if you really want to do this.
E85 Setup Content Analyzer, Pressure Sensor &...
Hey guys, my part out continues, sold my ProEFI harness but still have my E85 equipment for sale. The following is for sale: Flex Fuel Sensor : $350 shipped (believe this thing was $600) ProEFI 150PSI Pressure Sensor : $125 shipped Zeitronix Ethanol Content Analyzer : $150 shipped Fuel...
I think the reason it’s avoided with Uprev is because even if you have sensors giving you information on your ethanol content, our early 2000’s ECU’s don’t have any function to adjust timing based on that data. The e85 pumps say that the ethanol content can range anywhere from 51-85% ethanol to a remaining percentage of gasoline so you can add sensors and a display to see what level you’re at, but the ECU won’t know the difference. If I had to guess, you could probably still tune with Uprev for a specific ethanol content (e85, e100) if you can control it, but the wide ethanol range from the pumps is more of the problem. Might be worth researching ethanol fuels vs racing fuels at that point to see what makes sense if I end up being that conscious of what’s going into the tank.
If I come back in a couple years and go turbo then I’ll start corn feeding it lol 😂
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Bad idle and hunting idle isn't just a e85 issue in that area....just saying...
I think the idle issues were more of a reference to the larger throttle body idea?
I know there’s a forum topic here where someone was able to use an Apexi piggyback to tune for a VQ throttle body. Shouldn’t be impossible to figure out on my own with Uprev later on if I decide to try it anyways..
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I'm talking with my own experience from my initial tune and issues I'm still having that is based from some where...vq tb is something completely different but I don't want to dance around that to much...
I replaced the 2JR injectors with Ultra Pro injectors from rockauto. Also replaced the Altima plenum with the Rouge plenum. All new gaskets and O-rings. Car is misfiring just as badly if not worse than before I swapped injectors on cylinders 3 and 4. Getting a check engine code for multiple/random misfire. I tried looking for a vacuum leak and tightening up hose clamps, but no luck. This car is really starting to piss me off. I really wanted to be done with part today so that it would be ready for tuning, but it doesn’t look that’s going to happen and I’m probably not going to have much free time in the near future to diagnose what’s wrong with it due to my full time job ramping up with work this coming month.
It could be that I’m having bad luck with cheap fuel injectors. I may have some time tomorrow to use my smoke machine to try and find a vacuum leak if that’s the issue, it was just too dark to try it by the time I thought I was going to be finished working on the car today.
Coil packs and connectors were never moved so that shouldn’t be an issue.
Car was running and driving fine yesterday. Super frustrating.
It could be that I’m having bad luck with cheap fuel injectors. I may have some time tomorrow to use my smoke machine to try and find a vacuum leak if that’s the issue, it was just too dark to try it by the time I thought I was going to be finished working on the car today.
Coil packs and connectors were never moved so that shouldn’t be an issue.
Car was running and driving fine yesterday. Super frustrating.
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Pull your plugs and post a pic, look down your plug tubes as well...
I'm starting to think your timing is off a well by a tooth or two on the intake cam, sounds silly but improperly timed you will get some where from a no start to misfiring.
I'm starting to think your timing is off a well by a tooth or two on the intake cam, sounds silly but improperly timed you will get some where from a no start to misfiring.
Checked for vacuum with the smoke machine and didn’t see any leaks.
Checked fuel injector resistance;
1 - 13.8 ohms
2- 14.0 ohms
3 - 14.3 ohms
4 - 14.2 ohms
All injectors came with a test report like this (looks like the numbers are all copy and paste across all sheets);
![Finger Font Material property Thumb Gesture]()
Going to check spark plugs next. I ran the engine and pulled connectors just to verify that it’s not a no spark issue.
Checked fuel injector resistance;
1 - 13.8 ohms
2- 14.0 ohms
3 - 14.3 ohms
4 - 14.2 ohms
All injectors came with a test report like this (looks like the numbers are all copy and paste across all sheets);
Going to check spark plugs next. I ran the engine and pulled connectors just to verify that it’s not a no spark issue.
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