I just got a series II pump in place on my series I; it went very smooth thanks to this write-up! Thanks to those that have contributed.

For the fuel line that goes to the other side of the tank, I used an AutoZone fuel line repair kit - FORD 3/8" quick connector with 5/16" nylon hose.

Reusing the Series I pump connector is a brilliant solution. It will be obvious once you disassemble everything but the connector that's referred to by Skywalker is the one that connects the fuel pump to the fuel pump assembly. I just used a razor knife to make the slot. Getting that actual wires/terminals off is easy; just insert a small flat screwdriver perpendicular to the wire between the wire and the gray plastic tab that runs parallel to the wire.

One note on the fuel bowl design: It seems as if (note the "seems as if") the siphon system is designed not only to pick up fuel from the right side of the tank but also from outside the bowl (near the bottom). On the Series I assembly, the bowl fills up only by a small hole with an orange rubber "float" at the bottom. My thinking is that the bowl refills quicker with the Series II design.

Bumping this thread as I'm considering doing this myself. Anyone have any notes or things they wish they did differently during the install?

Not really. Just make sure you are very low on gas, get new plastic rings and you're good to go.

Glad the post had helped others. My fuel pump is still going strong. Biggest thing as noted is make sure gas is low when you do the switch. And make sure the ring is tight enough when you put it back on. I made such a mess when I went to fill the car and found out the ring was not tight enough...

Another word of wisdom.....if you buy a used Series II pump assembly, clean or replace the fuel filter before installing it. This might seem obvious to most, but it is easy to do and can prevent future issues. The Series II fuel filter is also a serviceable part number, if you want to just replace it instead of clean it.

I made the unfortunate mistake of not replacing or cleaning the fuel filter before installing a used pump assembly I bought off of eBay. Started having lean conditions and soft fuel cut at high RPMs. Turns out it was a clogged fuel filter.

The Series II fuel filter part number is LFB613ZE1. Cost is only $20-$25.

Good stuff. Just recently haveing the problem. And knew there was a problem when car started shutting off just under 1/4 tank. Researched and yeah was a comments issue. Blah blah blah. And bang found this post today just need to get paid and buy the stuff.
So where do I get the s2 from? Yeah budget is still issue but for new. Have a family so budget is issue.

Also I'm em currently under 1/4 a tank at a inclined drive way. Haha but don't want to put fuel in just in case the pump is shot. The car starts when cold but hard after been ran.
Idles fine unless revved. But in mind 1/4- tank. Don't want to put gas in and then have to much to due the job...

Does anyone know if the S2 fuel pumps are the same between auto and manual models? I have a local wrecker S2 thats an auto and I'm looking to snag the fuel pump, just need to know if it'll work the same.

There is only one fuel pump

Thanks Team. Looks like I'll pick it up tonight.

Just did this today and got a few things to add.

This swap would be complete plug and play with no modification necessary if you obtain:

- Series 2 fuel pump and assembly
- Left side series 2 fuel level sensor
- Right side series 2 fuel level sensor

I didn't have a chance to take pics bc my gloves had fuel all over them but the left side fuel level sensor has the wiring connector that plugs directly into the fuel pump assembly so you don't need to cut it off and de-pin it and connect it to your series 1 level sensor.

Also the right side level sensor has the fuel hose that crosses over into the left side tank and connects to the pump assembly so you don't have to cut the connector off your hose.

I ended up using the series 2 left side fuel level sensor and connector so I did not have to de-pin any connectors. Just plug and play.

But my right side ring of death to remove the assembly was giving me a hard time so I stayed with the series 1 Fuel level sensor on the right side and cut my fuel hose and used 5/16th hose to connect to the assembly.

All in all a very easy swap and having both side fuel level sensors makes it a direct drop in. Although the right side level sensor is not necessary at all.

Thanks for your post and work summary :)

Not certain if you are aware but the Series II RX-8 has a slightly larger Fuel Tank(s), from memory about 5-6 litres, just around a gallon larger when compared to S1.

Anyway since you installed S2 specific Fuel Level Sensors with attached floats, how has the accuracy been with your dash meter fuel gauge?

Have you noticed errors in actual fuel levels from the dash reading in your S1.

I know a guy here a few years ago installed an S2 specific Dash Cluster/Meter gauge assembly in S1, and he got it to work 'reasonably' well, however the outcome was reversed as he did not change the Tank Level Sensors, he was getting false dash readings, saying car has a 1/4 of a tank of gas when in fact it was almost empty.

Outcome, eventually he went back to his original S1 Dash Cluster.

No problem man. I actually did read earlier that the S2 fuel tank was a gallon larger than the S1. As far as fuel level accuracy I can't say for now as I just did the swap today with about 3/4 tank left. So I'll have to report back on that as I get some mileage on it.

I actually didn't replace both fuel level sensors. Just the left side. The retaining ring on my right side pump was giving me a hard time so I just used the method in the OP to make the fuel line fit the assembly. If I have any problems with fuel level I still have my S1 fuel level sensor that I can de-pin and retrofit with the S2 connector.

^ I can't imagine a gallon of fuel really throwing off the S1 level sensor by much. With 1-2 gallons of fuel left only you are sitting damn near empty on the gauge regardless...

Exactly what I was thinking at a gallon of fuel or even 2 gallons left you'd still have the gas light on. I doubt it'd throw off my gauge significantly.

No it is just going to tell your dash meter you have more fuel in the tank than what you really have, remember the S2 gauge you installed is designed to float and read lower (range of its bi-metal strip) than what it is actually doing in your S1 fuel tank.

The tank gauges measure levels in milliamps to determine actual fuel reading levels, let alone the fact that owner has mixed up the two tank units (one S1 and one S2).

Whether it will be or is an issue, I am merely helping and pointing it out based on facts from an owner who change his fuel gauge at the dash end, in his case it was the opposite, he had less fuel in tank than what dash meter was telling him.

Yeah I know I was a bit worried about putting one S2 level sensor and leaving one S1. I know it won't be completely accurate as it will read I have one extra gallon in the tank than I really have. So I guess I just have to eye it and make sure I stay above empty. Don't wana risk running dry.

Plans for now are to keep it above a quarter tank and just keep a reading of the trip meter on each fill up so I can get my own general idea of how much fuel is being used. Thanks for pointing it out Ash.

I find that hard to believe. It's just a position sensor. Empty should be empty regardless. Most gauges read full even though the tank might be a gallon below full. Only if they changed the sensor output should there be an issue. Those values are listed in the chassis/bodywork section at the end of the service manual. I have the S1 info posted on the forum somewhere.

Here it is. You can get the dash to display the sensor output values to compare against

https://www.rx8club.com/series-i-tec...3/#post4600065


All we need is the S2 info. I probably have it on my computer, but am on my phone at the moment.

Yes it is 'just' a position Sensor and the S2 float has a longer travel/movement as it is a different Sensor for the larger gas tank, graded readings on sensor strip (in m-amps as each segment changes it reads a different m-A setting).

So tell me why was a S1 member who install an S2 Dash Cluster in this forum always showing a lower gas reading when he knew how much he put in?

It is all posted in this forum, you can search.

Here is a S2 Fuel Sender which is not an S1.
F190-60-960+970 S2
F151-60-960A+970A S1

BTW, and it is not ""empty is not empty regardless"", if the smaller S1 tank is empty (with an S2 float) the float would still be reading as it has fuel when it does not, look at my picture of S2 float.
The S2 fuel tank is deeper than a S1, but the 'S2 Float Senor' mounts in the exact same hardware bracket (parts) as used in a S1 tank.

5 liters volume spread out over the whole bottom tank area cannot be that much "deeper" unless they changed the entire tank profile, which I suppose is possible. The float arm could be bent to allow the zero point to be achieved. There could be any number of reasons why the S2 dash is not indicating correctly. Without going through the whole thing in detail i can't say for sure, which I have no reason to do.

Boring!

Sorry. Also meant to say that in all liklihood it would be easier and probably make more sense to stay with the S1 sensors as Ash suggested.

Where can you get hold of an s2 assy these days ... I can't seem to find it available anywhere (except Mazda). Mazmart have stopped stocking them .

Probably your best bet to scout your local wreckyards, although I know Partsgroup has some good parts from time to time. Might have some luck with them. Or even eBay.


Troubleshooting your fuel level sender

On another note this writeup ^^ is extremely helpful and sheds alot of light into the fuel starvation problem that plagues the 8 and how the fuel system functions. Read up guys.