Is anyone running a TPI fuel pump with their TBI? I'm swapping my rearend for a disc brake setup and figured since the rearend is out of the car I might as well try to replace the fuel pump for a higher pressure pump. If anyone has done this, do I need to change the rubber TBI fuel lines or can they handle the high pressure? Thanks dudes or dudettes.

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92' Camaro RS 305 TBI
Best 1/4 mile - 14.6 @ 96 mph w/NO NOS
Best 60' - 1.9 secs
Check it out
https://www.thirdgen.org/rides/index.tgo?action=view&rideid=4860

 

Anyone? Going once, going twice?

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92' Camaro RS 305 TBI
Best 1/4 mile - 14.6 @ 96 mph w/NO NOS
Best 60' - 1.9 secs
Check it out
https://www.thirdgen.org/rides/index.tgo?action=view&rideid=4860

 

Putting a TPI doesn't raise the pressure at all. The TBI regulator sets the pressure. The pressure will be the same UNLESS the new fuel pumps volume is greater than the volume handling capability of the feed lines/regulator/retun lines/filtre(s), but I think you're good.

 

Well the TBI puts out 9-13 psi and the TPI pump puts out about 45psi and was wondering if the TBI lines would be able to handle the higher pressures. Don't want to find that out the hard way with a real flame job on my car driving down the road.


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92' Camaro RS 305 TBI
Best 1/4 mile - 14.6 @ 96 mph w/NO NOS
Best 60' - 1.9 secs
Check it out
https://www.thirdgen.org/rides/index.tgo?action=view&rideid=4860

 

I don't think you can do that without breaking something. That system was meant to handle 9-13 psi, pumping 45 in there will prolly just blow some seal out or push WAY too much fuel thru the injectors.

 

I'm only going to say this once. The fuel pump doesn't "put out" any pressure. It puts out flow. Some pumps are just biult to handle higher pressure.

By restricting the flow of a pump with a regulator, you increase the pressure to whatever the regulator is set to... ie, if you take the TPI pump, place the input side in some water and just put a hose on the output side and aim it towards your buddy, there is essentally NO PRESSURE in the line as there is no restriction. That, too, is why the "return" line in an EFI system has little to NO PRESSURE!!! Ie, All fuel pumps (electric AND mechanical) are rated at "free-flow" rate in GPH, and also at a pressurized rate because the flow decreases proportinately with pressure. Ie, most flow at "free flow", lesser flow at 11psi, like TBI, least flow at 45psi, like TPI.

the major differences in TBI vs TPI pumps are the levels of flow and the ability to maintain high levels of pressure for long periods of time. ie, the TPI pump is more durable of a pump... If you use a TPI pump FOR TBI, it will last longer than the TBI pump. If you use a TBI pump for TPI, it will fail prematurely, get hot enough to melt stuff and will probably not not even be able to attain the appropriate 45psi+/- pressure at all!!!

Once again, your fuel system PESSURE will NOT INCREASE, unless you have the problems with restricted flow that I mentioned in the earlier post.

TRUST ME ON THIS!!!


[This message has been edited by fast_broker (edited October 24, 2001).]

 

fast broker doesnt know what hes talking about.

JUST KIDDING. Dont worry about replacing the pump unless you NEED to. ie, your oem isnt cutting it anymore. besides if you do a rearend swap, then find out you need a new pump, youll be able to do it much quicker because youve already done it once. doing it all at once seems to be fixing something that isnt broken.

 

I swapped a walbro TPI 255l/hr pump in for my OEM TBI pump. It ran just fine with the TBI and it still runs just fine now that I'm running a carb.

Steve

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Steve's Trans Am Temple

 

I am running the Walbro 255LPH TPI pump in my Camaro for 6 months now. Runs fine no increases in pressure. Getting prepped for horsepower though.

 

Well I decided to not mess with the TBI pump and just put the rearend back in. It's been a little over a month now since I did that and guess what...THE MOTHER F'ING PUMP BURNS OUT ON A FULL TANK OF GAS!!! !!!!!! Anybody want a Camaro?

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92' Camaro RS 305 TBI
Best 1/4 mile - 14.6 @ 96 mph w/NO NOS
Best 60' - 1.9 secs
Check it out
https://www.thirdgen.org/rides/index...ew&rideid=4860

[This message has been edited by pwdbychevy (edited November 30, 2001).]

 

Of course it did!

Fuel pumps are very intelligent, and like to break when they are swimming in a sea of gas. Nothing like trying to lower down a full tank! Try that on an Astro van, 27 gallon tank. Forget siphoning 27 gallons, you'd be old and gray by the time it was done.

Hey, we were about to switch AutoGon350's TPI for TBI. That's great news! I wasn't looking forward to the fuel pump thing. If your sure the TPI pump will work, then we'll just leave it in there.

[This message has been edited by V8Astro Captain (edited November 30, 2001).]

 

Well I contacted the Summit Tech guys and they told me that I wouldn't have a problem if I went with a TPI pump. He also said that I can run an inline pump and it will pull fuel through the dead pump in the tank but the pressure might be slightly lower. If you have an adjustable regulator then you can counter that pressure loss. What to do? Should I drop the rearend (again)or go with the inline pump?

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92' Camaro RS 305 TBI
Best 1/4 mile - 14.6 @ 96 mph w/NO NOS
Best 60' - 1.9 secs
Check it out
https://www.thirdgen.org/rides/index.tgo?action=view&rideid=4860

 

I thought that in order to run the inline your intank needed to be running? It acts like a pickup. I remember Damon saying something about it over on cz28.com. Hopefully someone can clarify?

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Chuck Kulchar
1991 RS
Open Element w/K&N
3" cat and Force II cat-back

 

I did some more research and found out that the inline pump will work but only if the motor in the bad pump can spin. I'm not about to purchase a $140.00 inline pump only to find out that the in-tank pump is seized or something and won't allow fuel to pass through. I guess I gotta do what I didn't want to do in the first place and drop the tank. I just bought a TPI pump to take its place. Wish me luck.


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92' Camaro RS 305 TBI
Best 1/4 mile - 14.6 @ 96 mph w/NO NOS
Best 60' - 1.9 secs
Check it out
https://www.thirdgen.org/rides/index.tgo?action=view&rideid=4860

 

Good luck. I'm waiting for my pump to die. It's original with 150K miles on it and the last 5K have been with a 330hp 350.
If you went with an inline pump you could just remove the intank pump, gain like a 1/4 gallon capacity and just run a pipe inline where the pump used to be. That's what lots of guys have done. Personally I'm going with a $98 255gph Walbro intake replacement when mine goes south. I probably should just get a 190gph but the extra flow might come in handy after some future plans.

 

Well it took me about 8 hours but I did it!!! I dropped that tank and it was full to the max! I had no way of draining the tank because it has an anti-siphon thingy at the end of the filler neck. It was alot of fun I put in the TPI pump and everything works fine however my inline pressure gauge still reads 13 PSI like the TBI pump read, WTF?! I don't know if this would be the appropriate message board to ask this but why is the TPI pump reading 13 psi when it's supposed to be 45psi? I'm positive that it's a TPI pump just incase anyone asks.

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92' Camaro RS 305 TBI
Best 1/4 mile - 14.6 @ 96 mph w/NO NOS
Best 60' - 1.9 secs
Check it out
https://www.thirdgen.org/rides/index.tgo?action=view&rideid=4860

 

The guage should read the psi that you have the regulator set at.

Did you leave it set where it was?

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91 RS 5.0 TBI....LT4 cam....Edelbrock headers....3"Dynomax exhaust....5spd.... 3.08.....Ultimate tbi....afpr...ZR 255-50's...Koni's

 

I haven't touched the regulator yet but I have the pressure gauge mounted before the regulator. It's the only place I could mount it since it's on the throttle body on a TBI. It's an adjustable regulator from Turbo City. I've never really messed with it much but when you screw it out does that lower or increase pressure? I would imagine that it lowers pressure. Correct me if I'm wrong.


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92' Camaro RS 305 TBI
Best 1/4 mile - 14.6 @ 96 mph w/NO NOS
Best 60' - 1.9 secs
Check it out
https://www.thirdgen.org/rides/index.tgo?action=view&rideid=4860

 

That's what Broker was trying to tell you. The line pressure will only be whatever the regulator permits. If it didn't your pressure would be way to high for the TBI. Congratulate yourself for finishing and having a system that should work well.

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93 9C1, Torquer heads, Comp Cams,TBI spacer, injector spacer, cut front springs, SS rear springs,F-body sway bar, Jacobs ignition, drain pipe intake in works.

 

Yeah fastbroker was on the money with this one. I never doubted his (or her)'s input. I just assumed that since the pressure gauge was mounted before the regulator that it would read 45 psi. I'll mess with the regulator tomorrow. Thanks peoples.


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92' Camaro RS 305 TBI
Best 1/4 mile - 14.6 @ 96 mph w/NO NOS
Best 60' - 1.9 secs
Check it out
https://www.thirdgen.org/rides/index.tgo?action=view&rideid=4860