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Am i thinking right>>>Fuel Pump advice?


Jersey

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Hey all. This is where i'm at -

 

'73 240 running a stock L28ET, stock ECCS, stock fuel pump, stock injectors, stock FPR, elec fan, 3/8" supply line, 10Ga wire to pump from relay, running @ 9psi. This is right at my limit of boost before she starts to ping. I ran a 13.33 with this setup...and i want 12's :twisted:

 

Last night, I took her off the road and back onto the jackstands to fab a 45deg SS downpipe and will start the NPR I.C. install tomorrow. I was thinking, hoping i guess, with these two things to bump the boost up a bit...maybe 12-14psi, and getting into the 12's. I have a feeling i'm running right at the edge of lean at 9-10psi because a little more psi than that and she starts to ping lightly and, the temp rises quickly on WOT runs. So, here's a few questions i have -

 

1. Should i upgrade from the stock ZXT pump? Is this what's causing my leaness?

 

2. If yes to #1, which one do you suggest? I've read bosch, Walbro and MSD. After these mods, i probably wont do much more (yeah, right)

 

3. I'm using a stock ZXT fuel filter (metal canister type) - Is this restricting me now, or will it if i upgrade the pump?

 

4. Is the stock FPR causing me any leaness now? If not, will i need to upgrade it if i upgrade the pump?

 

I know these are sort of tough to answer because all applications and Z's are a bit different but, if you have some experience and knowledge you could share, it would be much appreciated. Thanks in advance guys.

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1. Should i upgrade from the stock ZXT pump? Is this what's causing my leaness?

 

Seeing that it ran a 13.3 for you, i dont think its the problem, but it could start to be, one its like 20 years old, i dont think they work well over a certain fuel pressure/boost level either. ive heard good things from walbro and msd, both should work. I run a bosch cis pump for a porsche 944, but i went from this right off the bat so i dont know how high you can run the stock pump. best thing about the bosch pumps, i like the bosch pumps best myself, but that is an opinion of mine though. the msd, and walbro pumps are a lot cheaper though, and work fine.

 

 

3. I'm using a stock ZXT fuel filter (metal canister type) - Is this restricting me now, or will it if i upgrade the pump?

 

dont think its the fuel filter, but nto sure.

 

 

 

4. Is the stock FPR causing me any leaness now? If not, will i need to upgrade it if i upgrade the pump?

 

no its not the stock fpr, it should be fine, i have an adjustable, but i have personally seen the stock fpr on pumped up turbo L motors with hybrid turbos and all that jazz, and no complaints. i like my adjustable fpr because its got a guage i can see my fuel pressure at, and its anodized.!

i figure if i run high boost, i would just turn up the rail pressure to compensate, and not use a rising rate regulator, i dont think they work too well for our cars, being a mass air type system that will throw down extra fuel when it senses air.

 

 

what size is the return line on your car?

my buddy with a pretty hot turbo 240z had problems leaning out before he enlarged his return line, not sure what size it is on those cars, but when he elarged it, the pinging stopped.

 

what year is the efi setup on your car?

i learned the ideal year is the 83 manual trans ecu setup, 24btdc compared to 20btdc for 81, and retards timing 6 degrees more under boost.

 

one more thing that may be making you ping--lack of intercooler!!!!!

is it pretty hot in jersey?

that could be it too.

slap that intercooler on and start checking out the deals on ebay for a better fuel pump, and enlarge that return, i think youll be very happy later, and im sure more people will chime in to help you out.

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I agree for the most part with Len.

 

You need a better pump - that stock one flat-out will not flow enough. Take your pick - the Walbro 255 hp is a good choice, or the Porsche application Bosch pump. The Cartech (Pierburg) will work well too, but it's a bit more money. Don't use the MSD.

 

With a good pump, the stock fuel filter should be ok, as well as the stock regulator - the regulator will not cause you to run lean, rather if you are outflowing it, it will cause you to run richer at idle. It works just fine with the Bosch pump - I've run that combination.

 

Your pinging could be either the injectors running out of duty cycle, or just that you don't have an IC. I suspect it's the lack of IC, as I put 250hp to the wheels with the stock injectors, but that was with a Z31 ECU.

 

what size is the return line on your car?

my buddy with a pretty hot turbo 240z had problems leaning out before he enlarged his return line, not sure what size it is on those cars, but when he elarged it, the pinging stopped.

 

I highly doubt the restriction of a return line caused pinging (or lean-ness). All a restrictive return will do is raise your fuel pressure at idle and light loads. Of course, if he adjusted his base fuel pressure down because of the restriction, and not watched his fuel pressure drop when he loaded the engine, that could have caused his problem.

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You could always tap into your fuel line and run a temporary fuel pressure gauge (outside the car ofcourse) to watch your fuel pressure under boost to see if and /or when it drops off.

 

Absolutely. I've done that several times to verify proper operation.

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If you don't remember when you last replaced your fuel filter. Might be time to replace it. At 18 dollars cheap insurance :D . You can do alot of upgrades but restricted fuel filter can nullify them!

From my experience after you install your I/C and DP (don't forget 3" exaust. I was running around 11 to 12 psi. (at 93 octane) Don't think fuel pump upgrade will be needed YET!!!!! Now when you install larger injectors or use a RRFPR on stock injectors you may need to upgrade the pump.

An adjustable fuel press. reg. Is always good to fine tune but as Len says you will get 11 to 12 psi without it the direction your going After I/C, DP and exaust.

Len

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I would get a better pump, although if you are using the stock return line on your 240, it may not be large enough, and will cause problems for you.

 

Another thing to consider in the future is the pick up out of the tank. Fuel injected cars are generally larger, and I had mine enlarged on my 240.

 

I don't know what you are using for a coil, but I like the nissan one's from a 300ZX. They work well, and I never have to gap my plugs in tighter, even at 20psi. May be worth looking into. Just use the ZX ignitor, and wire the thing up, if you connect wrong, it won't start.

 

I am using a stock fuel filter, and I also thought it was a restriction, but if you think it is, pull the hose off the top, and turn on the pump. Man alive.

 

I think you are going to be real close to 12's when you get done. The 3 inch exhaust will really perk things up, I assure you. I am sure the NPR cooler will help too.

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I would say the minimum you will need is a better pump (providing you changed your lines, etc.). The aftermarket pump allows you to stay on the stock injectors a little longer. I am going to get the Walboro myself. ScottieGNZ highly recomends this pump. I am basically duplicating his setup since he always had good results. If you want to go to more boost your going to have to change your injectors. Your injectors are going to be maxed out even with the stock turbo. Good luck with the setup and remember to let me know when your going to the track. I want to see this thing run. :twisted:

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Guys, thanks much for all the replies and sorry i haven't replied since my post. Busy with the kids and building the SS DP this weekend.

 

Len - Thanks. I'm going to try and find the Walbro GSL392 for a good price locally. Seems like the pump of choice for the $ and will do the job. If i can't find it in time that i'm done with the IC install, I'll try the stocker and see how much she can handle. I will keep with the stock FF and FPR. Thanks for the info on the AFPR vs RRFPR. I'm using the stock 240 feed line as the return line - i believe it's 5/16". All the stock components are out of a '82 manual - stock 20btdc. Not sure what the stock dizzy retards under boost. Not that hot yet here in NJ. Hottest day we had so far this year i believe was around 80 so far. DP complete, I.C. mounted, firewall cut, waiting for mandral bent pipes and trying to figure out where to get silicon couplers locally. I am impatient, can ya tell??? :shock:

 

Sleeper - I will try to find the walbro pump. Question - why are you against the MSD-2225? Just asking because i saw others suggesting it in the archives. No big deal, just curious. I'm also hoping i'm not running to the end of duty cycle on my injectors. We'll see hopefully at the end of the week if the I.C. and DP will allow me to run more boost without ping. Thanks.

 

Yo2001- Good advice. Thanks.

 

Z-Gad - Will do, thanks.

 

Len - I replaced the FF when i did the T swap which was about a month ago. The DP i just made this weekend (pics for all to critisize coming soon :lol: ) is 2 1/2". The exhaust i currently have is also 2 1/2" mandral with a dynomax out the back. Hopefully, this wont be a major factor not being 3". Thanks.

 

Len - plugs are at about .042. I will try and take them down a bit after i hit the ping wall to see if it helps. Thanks for the suggestion.

 

Lockjaw - 5/16" return, 3/8" supply. I'm using a '75 280 tank so the pickup shouldn't be a problem. Stock '82zxt coil. Are you talking about the coils from the 300zxT or just the 300zx? And which ignitor - from the 280ZXT? I will look into it, just need to get more info. Thanks. Didn't know the 300 coil was that much stronger than the 280ZXT's. I'm hoping to get that last .33 with the DP and I.C. We'll know in a week or so. Thanks.

 

Pete - When you said that i'd need to change my injectors to run more boost, what boost poundage were you refferring to? Thanks for the luck. I'll need it! I should be ready to run at Island next wednesday or friday night. I will make a post to let any local guys know in case they feel like watching. Hope you and some others can make it. Run your Z! I'd really like to see Rags with either of his 2 Z's there! Either of them would be the Z to see, not mine.

 

the_dj - Man, i hoping. Thanks for the confidence.

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Sleeper - I will try to find the walbro pump. Question - why are you against the MSD-2225? Just asking because i saw others suggesting it in the archives. No big deal, just curious. I'm also hoping i'm not running to the end of duty cycle on my injectors. We'll see hopefully at the end of the week if the I.C. and DP will allow me to run more boost without ping. Thanks.

 

Because the MSD is rated at 40 psi. I found no data on flow above that, although I have not contacted MSD. The price is right, and unless I see data, I will conclude flow falls on it's face above that, and you get what you pay for.

 

I also use the 300ZX coil and trigger - it works well, I've encountered zero misfiring at boost.

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Pete - When you said that i'd need to change my injectors to run more boost' date=' what boost poundage were you refferring to? Thanks for the luck. I'll need it! I should be ready to run at Island next wednesday or friday night. I will make a post to let any local guys know in case they feel like watching. Hope you and some others can make it. Run your Z! I'd really like to see Rags with either of his 2 Z's there! Either of them would be the Z to see, not mine.

quote']

 

Jersey,

From what I understand 12lbs of boost on the stock injectors is stretching them pretty thin. That is why I bought the SVO injectors for my car. I didn't want to watch my car do a melt down from running lean. If you try boost higher than 12psi I would be VERY carefull. After all this hard work you don't want to watch it go up in smoke. The better fuel pump is a must for these boost levels with stock injectors. I'm really thinking of going to a higher injector before I even use the SVO injectors because when I go to a T3/T4e I won't have to find another set of larger injectors.

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Guest Zcarsmakemyheadhurt

Hey Jersey, everyone is watching your progress as so far you are ahead of the game with the ET. Now here goes my .02cents. Adding a intercooler alone isn't going to put you in the 12's but add it, the Walbro pump and a FMU that rasies fuel pressure under boost and you will be able to push the injectors a little further. So, I think if you boost that thing between 14-16psi and use the FMU to bring the fuel pressure between 70-80psi with the intercooler you may be able to even bring up the timing for more MPH. I hate to sound like a sales man but I do have pump, intercooler pipes, FMU and just about everything needed to hall some more ass. Good luck and enjoy the ride...

 

Alex C

AIM:boostmyride

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Sleeper - Thanks. Understand on the MSD pump. I will go Walbro if and when i do. Glad to here it's the ZX coil and not the ZXT coil you use that works well fo you. Hard to find ANY turbo cars around here in NJ.

 

Pete - Got ya - Stock ZXT injectors are 260cc/m. I was thinking about the SVO injectors. They run about 370cc/m, correct? I wonder if that's too much for the stock '82 ECCS, even with adjusting the AFM as much as possible? I'd hate to run rich as heck at idle and low end. Looks like i have something new to reseach. Thanks for the info.

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Thanks Alex. Posted the same time you did, why i didn't respond. Email me with a price shipped to NJ 07405 on the walbro GSL-392. Thanks and thanks for the info. Taking all this in Sleeper. Which injectors do you suggest? I will be keeping the stock '82 ECCS right now. I DO NOT have the $ for an aftermarket YET :-D Possibly next year but for now, i'll need to stick stock on this part. Thanks.

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Guest Zcarsmakemyheadhurt

I like big injectors more than a FMU but working large injectors on a stock ECM is tricky. I am sure you can get wide open throttle performance out of them but driveability sucks. Consistancy is also at a loss most of the time. Adjusting the AFM could help maybe at idle but you need to adjust at a spacific rpm and vacume, adjustablility you wount get out of tightening a spring. So many ways to make power I tell ya, FMU's are the way with smaller injector cars I think. I'll get to you Jersey, take care.

 

Alex C

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Cool. Thanks guys for the knowledge. I think the first step is to upgrade the pump and then i'll go from there - injectors/fmu. Alex, shoot me an email with a price on that Walbro when you get a chance unless you just wnat me to call ya? Thanks again all.

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