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DIY Fuel injection thread.


yoeddynz

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Braided sheathing and heat shrink looks a million times better than tape.

This is true but it's an absolute cunnyhole when you decide to change your wiring later on haha.

 

Although most people dont like it, I like the split wrap loom stuff for a good compromise between not looking like a taped up mess but also being easily accessible later on to tinker with.

Depends on how complex the loom gets I guess.

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Oh, completely forgot about that. I did actually order braided sleeve, lol.

 

Ill be following the layout of the standard loom as much as possible, but ill take note and care to keep sensors away from noise. TPS has shielded wire, and there will be zero solder joins if i can help it.

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Who knows about proper O2 sensor placement? Once my leg is working again, and i have fixed the fuel leak on the Rover ill be getting the bung for the wideband welded in.

 

My plan was to install the bung just after the Y-Pipe, so it reads both banks, but due to the design of the exhaust the Y-Pipe is damn near half way down the car. Is it still a go to install it there, or is it too far away? If i cant install it there, what are the implications of tuning the engine using only one bank of O2 data? Ill have the engine running as well as possible, so hopefully no/minimal differences between the two banks.

 

This is the layout of the exhaust (albeit not my car, mine is no where near as tidy lol)

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At the Y will be fine, you actually dont want it too close to the head. An increased risk of air leaks ahead of sensor is the only major downside.

 

I've burned through a few sensors for various reasons, the main advice re: widebands I can pass on is:

 

1. DO NOT LET WIDEBAND RUN WHILE ENGINE IS NOT RUNNING.
This was #1 reason why I was blowing up sensors.
The sensor gets to 700deg or so, and then first crank of the key blows this big woosh of cold air past it and cracks it.
Better to have engine start first and then start the oxy sensor heater from then onwards.
A previous good suggestion from someone here was to wire o2 sensor power to a relay that's triggered by your oil pressure light.

 

2. Do not run the engine with the wideband powered off / unheated. It clogs them up.

 

3. You need to mount it on a 90 degree angle to the pipe or preferably higher if there is space. So moisture doesnt condense on the sensor, from memory i think on a 45 degree angle to vertical orientation was best. This is more important than how close it is to the head. 

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As Roman Dave said.  in the y pipe will be fine,  closer to the top of the pipe the better.  

 

Tuning off one bank probably isn't much of a drama.  you're not going to know which cylinders are running leaner/ richer either way.  unless you run 8 o2's or egt's.   if you do go pre y pipe,  put a bung in both banks and swap the sensor over once you've tuned off one side. then recheck

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Thanks for the replies guys. The Y-Pipe isnt too far away and will cool the sensor down or anything?

 

Reading about your experiences made me plan my wiring differently, Roman. I will be wiring the O2 sensor so that it only has power when the fuel pump does. This will mean it gets a small pulse when the pump primes initially, but wont be powered unless the ECU turns the pump on.

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The sensors are heated. so no drama about cooling it.     

 

they usually  die from condensation on a hot sensor  (hot sensor on cold start as roman says)

overheating being too close to head.

vibration  will also crack the ceramic's

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I wouldn't risk it with the Wideband being powered up on initial fuel pump prime - probably still enough time to heat right up and then have cool air cranking past on start up. If it were me I would use a delay timer that activates the Wideband say 5sec after the oil pressure lamp goes off.

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I've got a datalog of it somewhere (Davelife)

 

But it takes a good 10-15-20 seconds sort of thing to warm up, a 2-3 second prime I doubt it would even get to 100 degrees.

The problem I was having was when I would sit there for 15 mins with key turned on, wideband steaming hot on a dead cold motor because I was fiddling around on the laptop or something.

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At the Y will be fine, you actually dont want it too close to the head. An increased risk of air leaks ahead of sensor is the only major downside.

 

I've burned through a few sensors for various reasons, the main advice re: widebands I can pass on is:

 

1. DO NOT LET WIDEBAND RUN WHILE ENGINE IS NOT RUNNING.

This was #1 reason why I was blowing up sensors.

The sensor gets to 700deg or so, and then first crank of the key blows this big woosh of cold air past it and cracks it.

Better to have engine start first and then start the oxy sensor heater from then onwards.

A previous good suggestion from someone here was to wire o2 sensor power to a relay that's triggered by your oil pressure light.

 

2. Do not run the engine with the wideband powered off / unheated. It clogs them up.

 

3. You need to mount it on a 90 degree angle to the pipe or preferably higher if there is space. So moisture doesnt condense on the sensor, from memory i think on a 45 degree angle to vertical orientation was best. This is more important than how close it is to the head. 

Ha ha ha...so topical to me at the moment. I have only just killed my second wideband sensor and most likely for the same reason as Dave has posted above. My first sensor I think got a bit iffy from a lot of excess fuel when I was trying to tune the 12a carb turbo. Possibly killed it with reasons above also. Second sensor which I put in a couple of years ago finally started throwing up the E8 error code. I only just happened to ring NZ performance where I bought my MTX-L kit and will get another sensor. Funny enough, since I was annoyed Ive killed another I did some reading and found this info here which backs up what Dave has just said..

 

http://www.nzefi.com/bosch-lsu-wide-band-airfuel-ratio-lambda-sensors-fail-often-aftermarket-performance-applications/

 

I have mine installed on one bank. Its possibly too close to the head although its actually no closer than where the factory mount them. I will move mine down to after the Y pipe but last time I looked it wasnt going to be easy as fuck all room around in my tunnel (little car life)

 

Dave - that idea of rigging the sensor up to a relay powered by the oil light is fantastic! I shall do that. For now I have disabled the sensor on the ECU and just running off the maps. Will be interesting if it makes much difference to economy or running.

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I wouldn't risk it with the Wideband being powered up on initial fuel pump prime - probably still enough time to heat right up and then have cool air cranking past on start up. If it were me I would use a delay timer that activates the Wideband say 5sec after the oil pressure lamp goes off.

I was wondering about a timer as well. From what I read in the link I put above most factory ecus will know, I guess according to coolant temp, how much potential condenstaion there might be at start up. They then delay the O2 sensor from heating up for a few seconds.  So yeah- a timer based off the oil switch seems like a neat idea. But Diy timer? Jaycar kit I guess?

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This is true but it's an absolute cunnyhole when you decide to change your wiring later on haha.

Although most people dont like it, I like the split wrap loom stuff for a good compromise between not looking like a taped up mess but also being easily accessible later on to tinker with.

Depends on how complex the loom gets I guess.

Fabric loom tape like Tesa tape is amazeballs for stuff in the cabin.

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if you space the sensor out so only the very tip is in the exhaust flow, will help if you have over temp issues.  and can put piece of copper plate or something between the sensor and bung to pull a little more heat away from it.

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