Jump to content
SAU Community

Recommended Posts

Hi,

Ever since I have had my car (4 months), I have noticed it behaves differently as the level of the tank changes. Around half way, it seems to run rich (sluggish) and goes through the fuel FAST. When almost full and getting low, the car seems to run leaner and respond well to boost and spools up quickly, responsive and alive?

It's an r33 skyline S1 by the way.

What could it be?

Link to comment
https://www.sau.com.au/forums/topic/229355-half-a-tank-sluggish/
Share on other sites

Think I might go with something like a Tomei Fuel Pump - 255L/H for skyline. Do I need a tune after the new pump is installed if using the same regulator?

Thanks.

How exactly do you tune a fuel pump? If you install a large fuel pump with stock injectors, there are gonna be issues as the pump wull not fully be filled before going to your injectors. I may be wrong.

Yeah could be mate, I'd replace it to be safe.

Mine went without warning, My R33 s1 wouldn't start at Autoone one day, so I tapped the bottom of the tank to get her started and speed home. $180 for a walbro 400hp ( I think thats the brand?) and 30 minutes to install it myself.

They are piss easy to replace. Theres a guide on here somewhere.

I wouldn't waste my money on a brand like that. It just pumps fuel. A bosch 040 or 044 would do the trick. I only say bosch as it is a proven good brand and not too expensive either. Walbro isn't too bad depending on how much modification you want to do, but I hear they dont last anywhere near as long as a bosch. I am changing mine next week just for safety's sake anyway. Car starts properly and all, but I dont like the weird noise it makes sometimes when it primes.

Cheers.

I get the weird sounds when I am starting my car, and the pump is priming; but - I also getting a raising electronic sound from the pump when slightly lifting the rpm above idle.

Looks like it's time for a new pump.

Where can I find these bosch pumps for a decent price you mention trel?

Walbro isn't too bad depending on how much modification you want to do

And what do you mean about 'modifications' with the Walbro - mods to the pump itself or engine wise?. I here the Walbro's are made to operate at 15v? - Does anyone know if the flow will be fine at 12v or does the voltage need to be raised?

Noob question = How can my car get tuned with stock ECU and uprated fuel pump?

From what I'm thinking it can't be done without an aftermarket ECU (eg.Power FC) - Will an SAFC suffice?

Thanks everyone.

Sam.

I get the weird sounds when I am starting my car, and the pump is priming; but - I also getting a raising electronic sound from the pump when slightly lifting the rpm above idle.

Looks like it's time for a new pump.

Where can I find these bosch pumps for a decent price you mention trel?

And what do you mean about 'modifications' with the Walbro - mods to the pump itself or engine wise?. I here the Walbro's are made to operate at 15v? - Does anyone know if the flow will be fine at 12v or does the voltage need to be raised?

Noob question = How can my car get tuned with stock ECU and uprated fuel pump?

From what I'm thinking it can't be done without an aftermarket ECU (eg.Power FC) - Will an SAFC suffice?

Thanks everyone.

Sam.

Ok well, bosch pumps can be found anywhere, repco, bursons etc. Try Kudos Motorsports on here he has them pretty cheap.

Modifications with Walbro I mean engine mods, I hear they shit themselves easily. The bosch pumps are best by what I hear.

You can get your car tuned with stock ecu by doing a re-map on it. SAFC is a fuel cut defender. Why do you want an SAFC? Are you getting fuel cut issues with your car?

Hope this answers some of your questions.

Ok well, bosch pumps can be found anywhere, repco, bursons etc. Try Kudos Motorsports on here he has them pretty cheap.

Modifications with Walbro I mean engine mods, I hear they shit themselves easily. The bosch pumps are best by what I hear.

You can get your car tuned with stock ecu by doing a re-map on it. SAFC is a fuel cut defender. Why do you want an SAFC? Are you getting fuel cut issues with your car?

Hope this answers some of your questions.

Hi mate,

No fuel cut issues with the car at the moment. I think the ecu has been remapped and wiring loom has been modified - posted a thread a while back 'What the hell is this?!'. As per running the stock pump, which I think is going to go soon, I am anticipating a decrease in air: fuel ratio which I think can be resolved using an SAFC to moderately tune the engine due to the increase in pressure with the new pump, due to the fact the car was remapped with a dodgy pump.

How much do the bosch's go for? - I am looking for a direct in-tank replacement.

Thanks.

Sam.

ok there is a DIY on how to install the bosch 040. They are a good pump, but i dont know what you lot are complaining about the priming noise. ALL good pumps will make the noise when u turn the key on. My 040 humms all the time, i have done the 14v mod to it too.

Just cause ur fuel pump makes a noise it is in no way stuffed.

EDIT Written by: Choku_Dori

Edited by blck32

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
    • I would put a fuel pressure gauge between the filter and the fuel rail, see if it's maintaining good fuel pressure at idle going up to the point when it stalls. Do you see any strange behavior in commanded fuel leading up to the point when it stalls? You might have to start going through the service manual and doing a long list of sensor tests if it's not the fuel system for whatever reason.
    • Hi,  Just joined the forum so I could share my "fix" of this problem. Might be of use to someone. Had the same hunting at idle issue on my V36 with VQ35HR engine after swapping the engine because the original one got overheated.  While changing the engine I made the mistake of cleaning the throttle bodies and tried all the tricks i could find to do a throttle relearn with no luck. Gave in and took it to a shop and they couldn't sort it. Then took it to my local Nissan dealership and they couldn't get it to idle properly. They said I'd need to replace the throttle bodies and the ecu probably costing more than the car is worth. So I had the idea of replacing the carbon I cleaned out with a thin layer of super glue and it's back to normal idle now. Bit rough but saved the car from the wreckers 🤣
    • After my last update, I went ahead with cleaning and restoring the entire fuel system. This included removing the tank and cleaning it with the Beyond Balistics solution, power washing it multiple times, drying it thoroughly, rinsing with IPA, drying again with heat gun and compressed air. Also, cleaning out the lines, fuel rail, and replacing the fuel pump with an OEM-style one. During the cleaning process, I replaced several hoses - including the breather hose on the fuel tank, which turned out to be the cause of the earlier fuel leak. This is what the old fuel filter looked like: Fuel tank before cleaning: Dirty Fuel Tank.mp4   Fuel tank after cleaning (some staining remains): Clean Fuel Tank.mp4 Both the OEM 270cc and new DeatschWerks 550cc injectors were cleaned professionally by a shop. Before reassembling everything, I tested the fuel flow by running the pump output into a container at the fuel filter location - flow looked good. I then fitted the new fuel filter and reassembled the rest of the system. Fuel Flow Test.mp4 Test 1 - 550cc injectors Ran the new fuel pump with its supplied diagonal strainer (different from OEM’s flat strainer) and my 550cc injectors using the same resized-injector map I had successfully used before. At first, it idled roughly and stalled when I applied throttle. Checked the spark plugs and found that they were fouled with carbon (likely from the earlier overly rich running when the injectors were clogged). After cleaning the plugs, the car started fine. However, it would only idle for 30–60 seconds before stalling, and while driving it would feel like a “fuel cut” after a few seconds - though it wouldn’t fully stall. Test 2 – Strainer swap Suspecting the diagonal strainer might not be reaching the tank bottom, I swapped it for the original flat strainer and filled the tank with ~45L of fuel. The issue persisted exactly the same. Test 3 – OEM injectors To eliminate tuning variables, I reinstalled the OEM 270cc injectors and reverted to the original map. Cleaned the spark plugs again just in-case. The stalling and “fuel cut” still remained.   At this stage, I suspect an intermittent power or connection fault at the fuel pump hanger, caused during the cleaning process. This has led me to look into getting Frenchy’s fuel hanger and replacing the unit entirely. TL;DR: Cleaned and restored the fuel system (tank, lines, rail, pump). Tested 550cc injectors with the same resized-injector map as before, but the car stalls at idle and experiences what feels like “fuel cut” after a few seconds of driving. Swapped back to OEM injectors with original map to rule out tuning, but the issue persists. Now suspecting an intermittent power or connection fault at the fuel pump hanger, possibly cause by the cleaning process.  
×
×
  • Create New...