DIY: Installing Series II Fuel Pump in Series I
 

First a little background on why I even installed a Series II fuel pump. As many of you probably know, the Series I fuel pump is known to have many problems. The problem I was experiencing was fuel starvation on the track on hard left hand turns. Many have reported this problem when their fuel was getting on the low side. In my case, I was getting fuel starvation after only being down a few gallons. I researched many solutions and decided on going with the Series II fuel pump since my car is fairly stock. I am happy to report I just tested the new pump at the track and no fuel problems.

Standard Disclaimer:I take no responsibility on your results following this DIY. Follow at your own risk!

Acknowledgements:
olddragger - For convincing me to go this route and all the help.
Parmer8 - For all the help
staticlag - For post on removing fuel pump

This is my first DIY so hopefully this will be useful.

Before starting on my DIY please read the following post:

https://www.rx8club.com/showpost.php...3&postcount=62

I will say removing and reinstalling the ring holding in the fuel pump is by far the hardest part. I bought a tool from Amazon which didn't work for me and just ended up in me breaking tabs on the ring. The only thing I did not follow, but should have was breaking off the black lock tabs. If you don't do this it will be very difficult to rotate the ring, but is possible. Again, this is the hardest part. Other than the ring everything else is very straight forward so don't let it discourage you. And yes WD40 is your friend! It really seemed to help a lot. Drench that thing! I had to use WD40 on both removing and installing since I kept the lock tabs in place.

If you have gotten the ring off time for a beer! Now onto installing the Series II pump!

Things needed:
Series II fuel pump
Very small flat head screw driver
5 inches of 5/16 submersible fuel hose rated SAE30R10 (found 1 foot at Napa)
2 Worm hose clamps

I bought my Series II (2009) fuel pump used. There are two major advantages to this. First is obviously cost. I paid $110 shipped. The other advantage was the car the seller had was totaled and thus could cut off a connector that is attached to the car that makes this job a bit easier. I will show this connector, and if you can have your seller do the same for you it makes things a bit easier. I do my best to explain what to do if you can't get this connector.

First some pictures of the Series II Pump:

This picture shows the top of the Series II Pump. The good news is the hose that is on the top of your Series I Pump will fit right onto the Series II Pump. The electrical connector will as well. So nothing difficult here.
Attachment 182434

This picture has the connector circled that my seller was able to cut off of the donor car. If you but new you will not have this connector. More on this is a bit. The connector on the Series I cars does not fit the Series II pump in the location where this connector is shown.
Attachment 182435

This picture is where the input fuel hose needs to go. The Series I hose will not fit this inlet (it is too small). This is why you need the submersible fuel hose.
Attachment 182436

Onto the connector you need to modify.

Here is the picture of the connector that should be inside of your fuel tank that you removed from your Series I fuel pump when you removed it. This connector will not fit the Series II pump. You need to remove the wires and pins from the connector.
Attachment 182438

To remove the pins/wires from the connector I used a very small flat head screwdriver as pictured below. If you look inside the connector there is a small plastic tab that you have to push down with the small screw driver and then just pull on the wire. The wire with the pin on it will come right out. Do this for both the black and red wire.
Attachment 182437

Since I had the correct connector sent to me with my pump, I then removed the pins and wires from that connector using the same method. Here is the picture of the connector from my Series II pump.
Attachment 182439

I then took the wires/pins from the old connector that are in the fuel tank and snapped them into my Series II connector. Make sure you put black and red wires in the correct placement so when you plug it into the Series II pump black goes to black, red goes to red. Here is a picture of my wires with the new connector attached to it.
Attachment 182441

So what do you do if you aren't have the Series II connector that fits the pump? See picture below. On the Series I pump there are two connectors connected by two wires. I've tried to focus on it in this picture. Take off both connectors and one of these two connectors is close to what you need. It will require you to modify the connector a bit to make it fit in the Series II pump. I was told by Parmer8 you just need to cut off a bit of the plastic, but not too much otherwise it won't lock. Once you have modified it so it will fit the Series II pump, remove the pins and wires and insert the pins/wires from the fuel tank into it. Sorry I don't have more details, but lucked out by having the connector that actually goes to the Series II pump.
Attachment 182440

Next step is to prepare the input hose. As stated the Series I hose is to smaller in diameter to fit onto the Series II pump.

Pictured is the input hose still attached to the Series I pump for reference that you should have removed when you took out your Series I pump.
Attachment 182442

Here is a picture of the input hose detached from the Series I fuel pump that is in the fuel tank. You want to cut off the elbow with a utility knife. I've circled roughly how much I cut off.
Attachment 182445

This is what it should look like once you've cut it elbow off.
Attachment 182446

On the Series II fuel pump you should fit your new hose onto it. Here is a picture of the package of the hose I found through NAPA. It isn't cheep! It was $30 for 1 foot! Don't use any other rating of hose though! This is VERY important since this hose will be submersed in fuel.
Attachment 182444

Cut a 5 inch piece of hose and put onto the inlet of the Series II fuel pump and secure it with a worm clamp.
Attachment 182443

Time to install the Series II pump into the fuel tank!

Take the hose you attached to the Series II fuel pump, and put another hose clamp onto it close to the other hose clamp and slightly tighten so it won't move. Slip the new fuel hose over the old fuel hose and then slide the second clamp where the two hoses overlap and tighten.
Attachment 182447

Then you just take the connector you modified and plug it into the Series II fuel pump. Again make sure you've connected the wires correctly. When you plug it into the pump black wire should go to black wire and red to red.

You then just insert the pump into the fuel tank and attach the output hose and the electric connector both of these need no modifications. Make sure when you attach the output fuel hose you hear a click!!! I did not the first time and let's just say when I turned on the car it was not pretty. Luckily I hate a towel around the fuel pump. Arrange the fuel pump in such a way that the output hose is not kinked.
Attachment 182448

Then comes the hell which is that ring. For me since I did not remove the locking taps it was a pain to tighten. When I tightened the rings it did rotate the fuel pump a bit, but since the output hose was still not kinked I called it good enough.
Attachment 182449

At this point time for a test drive. My fuel tank was at just about empty, and things worked out great. When I then filled the tank I had a leak because my ring was not quite tight enough. After a bit more hammering with the rubber mallet (and lots of cursing), I was finally able to get it tight enough to reseal. I did not replace my fuel pump gasket. I had a friend ride in back during the test drive to look for leaks. After I was convinced all was good I put the service panel and the seat back on.

One more picture that may help. Parmer8 sent me this one. It is left over parts he had when he installed is Series II pump. It will give you an idea of how much of the elbow to cut and which of the two connectors he used based on what he had left.
Attachment 182460

Again happy to report my fuel starvation problem is solved. The job really wasn't that hard other than the ring (seriously hate that thing). Hope this DIY helps!

man that is a good write up---points on all the work it took to do this.
Glad it worked for you and mine is still going strong after a few years.

I'm questioning the reliability of this... wouldn't it make more sense to use some type of coupler here so that you can put enough pressure on the clamp that it won't come undone?

The fuel pump isn't moving around for the hose to wiggle out. You could use a stronger clamp/coupletr, but the worm gear clamp works. 3+ years and no issues.

I got most of my info from OD...so thanks to him.

The problem is not the pump moving around, the problem is the amount of fuel pressure going through that hose.

Since there's nothing for the worm gear clamp to brace itself against, it basically doesn't do much. Either it puts little to no pressure on the inner hose making a loose connection - or even a leak, which could go undetected, or it puts too much pressure on it, pinching the inner hose and restricting the fuel delivery.

What you really need is some type of (brass?) coupler between the two hoses, that way you can put enough pressure on the clamp that it won't come undone or restrict fuel delivery.

most credits goes to you.... will be building mine soon ;)

Does anyone know this DIY re-uses the old series I pump assembly with a new series II pump, or a an entire series II pump assembly???

i believe he used the whole series II pump assembly and its pump as it is better as well as it is made by Denso not like the series I, made by Arram.

any updates on that mod? does fuel starvation still occur? i might give it a try if it fixes the problem

update??

will the stock series II pump be good enough to suport 330whp F/I, or would one still need to upgrade that pump as well?

id suggest going for the aeromotive pump insteadz...

So series II assembly and aeromotive pump or series I?

series II pump is a better option for those still on NA and on series I car...


aeromotive pump with series I assembly is ur answer with ur boosted application...

^^thats what I was thinking about doing, I just wanted to get all my ducks in a row....thanks y'all

for the connector you need to modify when you dont have the serie 2 one, is it the one that goes on the fuel pump of the serie 1?

With the changes to the wiring...and the suction assembly needed to use the Series 2 pump..it is much easier to just put in the aeromotive pump and leave it at that.

If you want you could just run it at the lower voltage setting to drop the output to a more manageable level for NA

I want the fuel starvation to stop the easiest and most simple way, i dont think the aeromotive will fix it but 2 pumps would or maybe a serie 2 would
Just want to be sure

Even with 2 pumps it doesn't "stop"....

It's good to about 1/8 tank if you are cornering really fast.....

Safest way to fix it is just to keep the tank above 1/2 on the track if you can...and above 1/4 at worst

got my s2 pump, came with the level sensor and connectors so no hassle for that. only need some fuel hose to instal it. might do it this weekend and try it on monday at local track to see if it works

update :

installed, took about 1h total to do it. was very easy to do with the right parts and tools. hardest part for me was to reinstal the ring (still not very hard)

started it, works like a new one. hope it will fix my issue

tried it on track today with a full tank and did not starved at all like my oem one. :D when i was done, i was at 3/4 of a tank and was still ok. next time ill try it from 3/4 to 1/2 to see when it will start to do it

Just wanted to report I've been using the pump at the track all year and have had no fuel starvation problems! I've was even down 11 gallons and still no issues! Well worth the time spent.

correction

I'm searching now for other threads that might have specifics but I thought this was as good a place as any to ask this question. I recently swapped my pump for the 2009 model to remedy the starvation problem but I can't get the seal at the union nut to quit leaking. I tightened the last nut so tight it still leaked but I couldn't get it off without cutting it in two. Ordered a new nut, replaced it last night, drove around the neighborhood and all seemed well, went to work this morning (slightly longer trip) and have fuel seeping from below the union nut. Anyone else having problems getting thing to seal? I lubed the gasket and the nut itself before installing. Am I missing something?

You talking about the (friggin) ring? Make sure its not cross thread and the gasket is ok. There is 3 tabs that need to be in a certain position. Removed mine 3 times and did not change anything and its not leaking

I thought the gasket went under the pump flange, now I'm starting to second guess myself and think it goes on top? Maybe that's the issue? What is the CORRECT location?

Took it off and replaced it again last night. I have the gasket (which is in good shape) under the pump flange like it shows in the exploded diagrams. I tightened the ring by hand until I couldn't tightren anymore then used a wrench to turn it until it quit. I also lubed the ring when I installed it as someone else suggested. Still leaking slightly under hard and fast g loads.

I'm a bit late to the party, but I put my Series 2 pump in a few days ago. Here are a few notes from my experience that may be useful to others.

On re-using the connector from the Series 1 pump:

The difference between the S2 socket and the S1 connector is that the key slot is on the wrong side. What I did was use my Dremel tool with a cut off wheel to carve a new slot on the opposite side of the connector.

First, I labeled the wire colors on the connector before removing them. To me, they looked green and black, so I wrote "G" and "B" on the connector. However, I believe the "green" wire was blue discolored by gasoline.
Attachment 196179
Then, there is a little white locking piece (at least that's what it seems to be to me) that I pried out, then removed the wires using a small screwdriver as mentioned in the original write-up.
Attachment 196180
Then I used the Dremel to carve the new slot. I was afraid I would go all the way through and end up with a loose fit, so I took it in stages and test fit in the socket in the pump until I had it right. The cut off wheel made a lot of plastic slag, so I cleaned it up with a razor knife.
Attachment 196181Attachment 196182Attachment 196183
Once I was happy, I went to the car and swapped the connector. The wires in the tank were smaller and the terminal seemed slightly different, but it fit and my gas gauge works fine.

On installing the new pump:

The outlet of the S2 pump comes out at a different angle than the S1 relative to the FRONT arrow. I feel it would be to your advantage to rotate the pump to take any strain off of the outlet hose. I would suggest having the FRONT arrow on the pump indexed to about 2:00, where 12:00 is the indicated position facing the front of the car. This seems to jive with how the OP's pump ended up. Mine turned to about 1:00 during tightening and I may go back and adjust it to take some of the strain off the hose. I believe if you actually have the S2 pump installed according to the FRONT mark, it will be hard to get the outlet hose snapped back on without the risk of kinking the hose.

On tightening the ring nut:

As stated, this is a PITA. I used a rubber dead blow hammer and a concrete chisel to loosen/tighten mine. Look closely and you will see that there is an extra tab in one spot on the ring, between the regularly spaced ones. I marked that position before removing the nut so I'd have an idea of where to go back to. Mine was initially at approximately 1:00-2:00 (again where 12:00 is facing the front of the car). When reinstalling, the start position for that mark is about 9:00 and there is the word "START" imprinted on the gas tank. I assume that is to help get the nut started when you put it back on. There is "MAX" or "MAXIMUM" imprinted on the tank around the 3:00 position - apparently that is as tight as it will go - about 1-1/2 revolutions. I was only able to get mine to go to about 11:00 - not quite 1-1/4 revolutions. I've checked it twice this weekend with a full tank and so far, so good.

I should have taken more pictures. If anyone would like me to get the pictures, just say so and I'll go get them. I'll probably do it anyway eventually . . .

great detailed writeup on the connector!!!

heres a vote on getting those extra pictures~!!! Goodjob!

Thanks! I'll get the pictures and try to edit them into my post above. Hopefully tomorrow evening, but definitely sometime this weekend.

Where did you get the pump?

I finally reached the end of my fuel pumps life last summer and just put in my order for my Series II pump. I will be performing the swap within the month (its cold here right now so Im not very concrete on the actual time frame)

If anyone is interested in doing this swap themselves and would like any further information and/or pictures that hasnt already been discussed/posted let me know and I will gladly post them here on this thread.

Well here is some useful data

Finally got around to installing the Series 2 fuel pump in my 2004 RX8. Here are a few pictures, hopefully they help the next guy looking to do this.

In these you can see where the electrical connector is located to use in the new pump. You can see where the connector needs to be modified to fit into the socket of the new pump. In doing this you shouldn't have to cut or splice any wires on the vehicle, just pop out the pins from the factory connector and put them in the modified connector. The pins will not snap in tight in the connector but with care you can get them to seat on the pins on the fuel pump, they will be snug when plugged in. Pay close attention to where the two wires went on the stock pump to ensure you do not mix them up. Pretty simple stuff here.

Ok so here we have the inlet hose. I did not particularly like the way others had been doing this. If using submersible fuel hose and worm clamps is your only choice then ok but that isn't really the way to do this. I have the luck of having a fuel line repair kit at my disposal though my work. Basically you cut the factory quick connect elbow off the inlet hose right at the quick connect making sure you have a good clean and straight cut. Install the tool to the cut line and crimp on a new quick connect elbow that fits the nipple on the new pump of course. This way you have a solid mod that has no way of leaking, unless of course you mess up the crimp, but in that case you can just cut off your new elbow and try again making sure you cut off as little of the hose as possible.

I didn't take any pictures of the stock inlet hose, as they are on this thread already, but in the second pic on this post you can see the new larger quick connect elbow cleanly crimped onto the the factory hose, now it snaps right to the new pump like it was meant to be.

The hose in the tank is from the siphon assembly on the other tank saddle. It has no pressure. An orifice in the internal bypass of the main pump assembly siphons fuel from the other saddle side into the side with the pump through this line inside the fuel tank. While an OE style connector is nice as per the post above, it us not really critical if performed properly as described in the DIY procedure.

I still don't get why guys are still buying used S2 pumps to modify and install in the S1 when brand new Walboro's can be had for $100 and Deastschwerks for about $120 from BHR.

Because a Walboro or Deastschwerks in a S1 assembly doesn't work as well as a S2 pump assembly. I still had fuel starvation at 1/2 tank with a 255 Walboro from BHR in my S1 pump assembly.

Just want to clarify the wire pin positions. The red wire would go in the position of the original green wire on the modified connector and the black to black. Is this correct?

Correct, black to black

Be advised that the parts listing for the S2 fuel pump has changed from what was originally posted on the forum back in 2009. In addition to buying the entire fuel pump assembly you can also buy the following individual fuel pump components separately; the main filter housing, the bypass regulator, the fuel pump, and the sock. Initially the pump was not available separate as it is now and the part numbers changed for the entire fuel pump assembly and the pump itself.

I recently installed a Deatschwerks pump in my S1 and still have a starvation issue when there is less than 1/4 tank of fuel. If I find an S2 pump assembly can I just reuse the DW pump since I already paid for it?

The pump isn't the problem...and the S2 basket isn't significantly different enough to fix the issue.

Do some research and then come back and ask different questions

lemme break out my silver-plated spoon here :)

what would you do to the OE fuel pump housing assembly to try and improve it's performance in low tank volume situations

Well in my case the fuel pump motor was a major contributor of the problem. I couldn't drive for more than 30 min without starvation issues even at very low demand such as light acceleration. The car would fall flat on its face.

With the new pump the issue is mostly resolved but it's still not perfect. Before I replaced the pump I read this thread, the Esmeril DIY, and the MazdaManiac thread and since my issues only started after a track day with 96 degree ambient temps I thought the pump was fried.

I'm really not asking to be spoon-fed but thanks guys. I'll look around for more info.

The easy answer...keep the tank above 1/4 :)

There are a few options.....a passenger side pump filling the drivers side cup will work for a bit longer...but will still starve out long before the tank is empty in high G loads

The only sure fix I have found is a surge tank and an external pump...with enough volume it can survive when the low pressure pumps slosh out of fuel

Or a fuel cell with a proper sump...

Problem is that there are rules for a lot of racing series that won't let you do either