I can run mine down to one dot and it still won't starve.

Me too, but that get a little scary on the track as I don't want to be that guy! I will add fuel at three dots to be safe. If I am doing time attack I will go down to two or three dots and add five gallons.:tiphat:

I been down to less than 20 miles to E aNd didn’t starve

Is everyone's Z1 systems still 100% operational without failures including secondary fuel pump?

Do the fuel level senders remain "accurate" as they were OE?
I know they're not the best to begin with but I read post #37 above which seemed to note a worsening issue when using the kit.

Before I pull the trigger on a kit that is exorbitantly priced, I'd like to make sure everyone's still happy with its performance.

Thanks for any help you can lend.:tiphat:

I haven't had any issue with mine since install and I am into my second year of running it.

Thanks! Are you running a switch or the like on the secondary pump from Z1? I saw a discussion on doing so so it doesn't have to run above 3/4 tank but didn't see final word or "how-to".

I do not have a on off switch since it sees mostly track time. On the track even full I was getting the affects of fuel starvation once I burn five gallons of full. I know some that said they were going to do a switch but none have posted up that I know of.

Ok hope someone chimes in with how they incorporated a switch.

Cut the relay control wire, or its ground, then connect the 2 ends you created to opposite terminals of a toggle switch.

Thanks for the response; however, I'm speaking of Z1's kit which doesn't include a relay. Simply piggybacks off of the OE pump wiring, which is suspect in and of itself.

Kit Includes:

Hydramat, magnetic mounts, and associated fittings
255lph in-tank fuel pump, vibration insulator, and associated fittings
Submersible fuel line for connecting Hydramat to pump
Submersible fuel line to connect additional pump to basket with hard line
Additional fuel pump harness with connectors to splice in to your existing wiring
Constant tension fuel hose clamps
Installation manual including diagrams and instructions

Figured they included a relay.

But since they dont, you can get a fuel pump relay kit. P/N FPHWK will do it.

For the price a relay, switch & battery harness should be included rather than piggybacking the Oe circuit. Doesn’t seem safe nor reliable especially for a street car.

Seems like you have lots of concerns and are talking your self out of Z1 kit. You should get phunk's kit as it is top notch. Those of us that have the Z1 kit have not experience any issues or at least I have not heard of any.

Yes I do, one of which being throwing part$ at an issue which might not be the fix.

I've also yet to hear from anyone with the Z1 kit that is using it on a street car running the auxiliary pump 100% of the time.

http://www.the370z.com/engine-drivet...runs-fine.html

I drive mine as a sometimes daily driver. I'm not sure what the issue is other than fuel economy which I have never been concerned with, because it is a sportscar lol. What part of not being a real fix are you speaking of. There isn't anyone in this thread that has said their issue with fuel starvation was not eliminated with the kit. You are in the track section so maybe people who don't track aren't committing because they have found a fix and moved on.


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:iagree:
I use my Z has a DD in the summer. With phunk's kit. Both pumps have to run all the time. No issues with the pumps.

Isn't that what they are designed to do run all the time regardless if you have one or two! Really the only kit I have heard issues with is the AAM twin pump system.

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Yeah, both pumps have to run.

I read the thread on the AAM kit.

The concern with running the Z1 second pump full time is that the driver side of the fuel tank in a Z is generally empty during normal driving, if the fuel gauge is at 1/2 or below.

This is because the factory fuel pump housing has a venturi jet pump that is recovering fuel to the passenger side of the tank so that the fuel pump can pick it up and send it to the engine. The recovery of fuel is quicker than the consumption of fuel, thus if you were to pull over the average Z on the average drive with a 1/2 tank of fuel and open both sides of the tank, you will find that the driver side is empty and the passenger side is full.

The reason the Z suffers starvation is because the fuel sloshes to the driver side of the tank on hard turns, and then there is none for the fuel pump to grab. The venturi jet pump is literally "powered by" bypass fuel leaving the regulator. So when the pump starves, the jet pump dies also. This is why a real bad case of starvation can leave you on the side of the road even with a significant amount of fuel in the tank. If you slosh it bad enough, there is just none for the pump, and the jet pump is dead due to no fuel leaving the regulator.

The Z1 kit eliminates starvation by "supercharging" the recovery of fuel to the passenger side by pumping it there with an actual fuel pump. This will make the driver side of the tank far more prone to just being entirely empty when driving the car at 1/2 tank or below, especially on the street where you will rarely turn hard enough to slosh fuel back over to it.

Electronic fuel pumps dont have a great lifespan when they run dry because the gasoline is what cools and lubricates them.

So if you DO use your Z1 kit on the street, I would highly recommend you put a toggle switch on it so you can turn it off. On the track it should be fine as it will constantly get sloshed fuel. On the street, it will run dry for long period.

The CJM RRP is a surge can system that operates under an entirely different principle and it is normal and required that both pumps run all the time.

I apologize in advance because I know this has got to sound rude over the internet: But you do realize you can purchase Hydramats and fuel pumps just about anywhere right?!

Thank you sir for the explanation as you have taught me something new and I appreciate your insight and experience. :tiphat:

Don't know that about the Z1 kit.

Wow, I was seriously considering Z1 kit for the price, but Phunk’s explanation pulls me back to the darker side lol.

If you are thinking about it. Get Phunk's RRP kit with the billet hat for the right side too. Then your system will be bullet proof. :tup:

A toggle switch could be made for Z1 and run it for track only

Or maybe just run stock pump a Y and a extra line with a Hydramat to passenger side

Yep, I am going to ask Seb about it this weekend as I have been running the kit for about two years without issue. I think what you are saying is reasonable fix.

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Did you happen to read the thread I linked of my issue? I’m not sure that it’s fuel starvation to begin with. That’s just what most members default to when the engine quits on the Z.

Car sputtered to a stop 1500’ after a 500’ right turn on the street which I took moderately at best and with 7 gal. in the tank. Suitcase in the back didn’t even shift. There’s more details in the actual thread.

I came proactively seeking starvation solutions one of which is the be all end all; however, IMO overkill for a street only setup and the other while no failures in the track cars it was meant for leaves ends untied for the street.

The only issue i've had was user error during install from not securing a fuel line down correctly.
Otherwise, the Z1 kit works.

Negatives are that I do still worry about the left pump being starved and running dry outside of track days, and I always keep the tank filled when possible.
And that my fuel lights have read 1/4 tank lower than they actually are ever since the install. (maybe also user error).

CJM's product quality is worth the extra cost, though, if budget permits. More stable solution, and nicer hardware than the Z1 kit.

This is a plague of the 370z, for the fuel level gauge to be off by around a 1/4 tank... often it will bounce between 1/4 off and correct, once or twice a tank. Or for some it just stays wrong, never reading entirely full.

Very often, it happens immediately after molesting the fuel pump housing for modifications.

I am not sure the source of the problem, I would need the car here to diagnose it. But dont feel bad, it is a common occurrence after fuel system work.

One suspicion I have, is the in-tank siphon hose slack interfering with the fuel level float arm travel. But I have in the past run into slightly worn level sensors that do not read correctly.

I did read your thread and I apologize if I was being harsh as I was not totally grasping your situation. I get it, you don't want to spend more money than you need to resolve your issue. From all the threads I have read on this issue regardless of track or street use only it seems there is a wide range between those that have issues and those that don't. I never experienced fuel starvation before hitting the track, even after boosting. Phunk kit was the first to successfully and reliably deal with the issue then came along the hydromats. For now these are the only two good options and one is more expensive than the others and deals with the issue you brought up and I got educated on and so you just got to decide which one is best for the money or live with the issue. Many street only folks have though it was worth buying the rrp system. I just decided to go a different route because of the build I have at the time I was looking to resolve my issue.

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Thanks and no worries; I didn't feel you were being harsh.

I've decided against the pre-packaged starvation kits at the moment.

Instead I'm replacing the entire OE fuel pump assembly with a new one due to the sound of my fuel pump motor prime changing during the issue. I have a feeling the fuel pump motor is on its way out.

I'm currently debating using a Hydramat in lieu of the OE pickup sock but trying to find out the O.D. of the OE pump inlet as Holley only offers 11mm for such a configuration.

Outstanding!

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If you re replace the whole assembly. Get phunk's billet top hat for it. Then you don't have to worry about it breaking.

Later this evening or tomorrow I can give you the part number for the hydramat that will best fit the bottom of th stock pump.

I’m not sure if you have looked at the fuel pump housing yet, but if not... putting a hydramat on there isn’t going to be so simple as just attaching it to the pump. You will need to cut away quite a bit of the bucket for the hydramat to spread out. It also isn’t going to reach to the driver side of the tank so it will only contribute a small bit to reducing starvation tendency because the only benefit will be collection of fuel outside the bucket, but still passenger side of tank only.

Many people who’s top hat is already broken reported a change in the fuel pump sound when it must have occured. With his last post mentioning a change in sound, he might already need the top hat.

Here is a pic of the hydramat that directly attaches to standard in-tank pumps. I just don’t have the P/N handy at the moment. Unless they have increased their line-up since I last looked at them, this is your best bet. But again, it will require a significant slice to be taken out of the bucket for the extended pick-up to reach out towards whichever direction you felt was best to send it.

We use them on our bucketless twin pump setup for some customers. (We might release a bucket add-on for the twin pump later. It’s got mounting positions for it already waiting).

http://host.cj-motorsports.com/products/z34twinpic4.jpg

This is such an annoying issue I am running a swirl pot external which cures my issues with starvation but I don't want fuel in the cabin any more
I was going to go with the cjm rrp and get everything back in the tank the problem is by the time I've imported it to UK and shops here want as much as the pump cost to fit it and run it up on the dyno to check fueling as im supercharged and currently using a 340 this issue would stand me at over 2k
I don't know which way to go :(

The z1 kit may well suit what I use the car for if I was to fit a switch to turn it off when just cruising as I only use the car as a weekend fun car/European road trip once a year and not a daily driver.




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might have to look into this, I realized I can't run more than 1 session without fuel starving

I dropped a small low presure low flow pump in the other side feeding the stock bucket with it's own power supply and a switch by my heated seat buttons

I only flick it on when low and driving quick and it works perfect I have ran down to Almost empty and it still doesn't starve
Stands me at about £60
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Thread Revival

[mention]Hotrodz [/mention] how has the kit been going after these years? Or did you end up changing it for the CJM kit?


[mention]nic370 [/mention] can you link or list the parts you used for your method, and how has it performed after the years also


Assume you both still have the Z.