So, I'm pretty sure I lost a fuel pump. This car is a bit different though, so I'm having some issues. It runs a Holley Projection, but with a stock TBI in-tank pump.

The previous owner (a good friend) told me that when he put this Pro-jection unit on the car, he attempted to leave in the stock TPI pump, and it overpowered the regulator in the Holley unit. Because of this, he went with a brand new (I have no idea which brand) TBI pump.

Considering the car has an L98 long block, open intake, and headers with 3" exhaust, I'm thinking I'm at the limit of the stock pump.

I *really* would like to keep the in-tank setup if possible, but I'm at a loss for what pump to buy.

Is someone aware of a low pressure fuel injection pump that will support the flow I need? From everything I read, the Projection unit itself (a 2D 670 cfm) will only support around 300hp anyway...

And I do believe it's the pump that's the issue, because when I crank the engine, fuel barely dribbles out of the injectors for a second, then stops. I've even bypassed the pump relay so it doesn't cycle off after a few seconds, and still no fuel to speak of. When I put power to the pump, I hear it "thump" as if it's turning on, but I can't hear it run after that. I believe the tank and line were free of crud, as the PO put them in from a donor TPI car and he tends to look things over pretty well...

I was just on the phone with the PO, and he mentioned remembering something about a Dodge truck pump application that supplied the needed flow at the lower TBI pressure...

Can anyone help me?

 

according to the instructions a pro jection system uses 21 psi. a tbi pump will not work. i am using a tpi pump ep241 on my tbi system and it does not over pressure my tbi regulator. it is set at 12 psi.

 

While I noticed that as well, I can tell you that this *did* work, at least for a while. That's why I'm looking for the correct solution, rather than throwing another TBI pump at it.

Is your TBI a Holley unit? I ask because it seems the stock GM TBI unit can handle the higher pressure, while it appears (from my friend's experience anyway) that the Holley unit cannot.

Thanks for any help you can give, and for taking the time to answer.

 

nope mine is a gm unit. you know that the projection regulator is adjustable. they say to start at 15 psi. i would think that is a tpi pump was overfueling it then the regulator is bad. from looking at the pics it is the same design as tbi. iirc there are people on here running the holley unit with a tpi pump. you do have a return line correct?

 

weird that the projection regulator couldn't handle the
pressure of a TPI pump-that pump is a common upgrade
for TBI and CFI setups...The pump that came with my
2 barrel projection i bought in 1993 came with a carter
built gerotor style pump that is very close to the factory
carter pump found in 1991-93 360CI dodge pickups,
besides meant for in-tank use,the dodge pump has a
turbine 1st stage feeding the gerotor 2nd stage while
the external inline carter projection pump is single
stage gerotor.The pump section of the carter pumps is
very well made,but i don't care for the cheap motor
they use with it's tiny,wear prone commutator.
Walbro is the best IMO

 

One92rs- I do have a return line, and it's a mystery to me as well as to why the regulator couldn't handle it. If it is faulty, I'm not sure what I could do to fix it, save getting a whole new unit (which I cannot afford). Perhaps there's a spring internally that could be replaced, but with what?

8t2- I'd prefer a Walbro pump myself (I have a ball-bearing Viper pump sitting here staring me in the face)... Do you think the 91-93 Dodge application will work for in-tank?

 

yes mine has one. these cars came with them from the factory if it was fuel injected. you regulator is also adjustable as well.

http://www.holley.com/types/Commande...ce%20Parts.asp

 

I have a holley tbi.

I ran a walkbro 255lph pump and it overpowered the holley return system.

I went with the ac delco tpi pump with no problems.

I am running 21 psi of fuel pressure.

They offer rebuild kits for the holley throttle bodies. I do not know the part #'s.

My stock tbi pump would not go anywhere over 15 psi and would not supply enough fuel volume for my application.

you need to go to the tpi pump and determine what is wrong. The diaphragm in the regulator could be bad. also the stock regulator will not go over 24 psi. you can buy different springs for higher pressures.

 

The 91-93 F/S dodge pickup pump i mentioned is an
in-tank pump-in the original dodge app,the pump is
inside a plastic pump/sender assembly that includes
a small reserve chamber.Back when i was thinking about
using this pump as an upgrade on my crossfire z28,i
tried to ID just the pump itself and couldn't find it.
Looked at a ~1994 dodge dakota fuel pump too and it
was close to the 91-93 360 pump but was single stage
without the turbine 1st stage.I ended up using a walbro
single stage turbine meant for an unknown original app
it was fairly close in dimensions and mounting to my
original GM pump.

 

Right, I understand the regulator is adjustable, but according to the guy who built the car, he tried to adjust it and it wouldn't adjust low enough.


UnderCover89TBI- Thanks for the info. At least I know it's theoretically possible then with the Holley unit. I was having trouble confirming it prior to that. Maybe I have some issue with the return system? Also, the pump you're running is the "241" pump that everyone suggests, correct? That's good info about the Walbro pump, as I'm sure the pump I have is at *least* 255, if not larger.


Thanks to all so far for the info. It appears I'm fighting more than one issue here.

 

Update:

Spoke to my friend, the previous owner, today after reading and getting feedback here. Apparently, I misunderstood the issue with the TPI pump. It was not a regulation issue, but an actual physical leakage issue. He could not get the fittings for the inlet and return to stop leaking at the TB, and also had a leak from the regulator. I'm going to get a TPI pump, and then address these other issues.

Has anyone experienced external leaks like that?

Also, what's the cheapest/best place to get the TPI pump? The parts store I use did not have AC Delco, only Airtex and Carter (both do make a pump for the TPI application...). Anyone know anything about them? Also, they do list an "upgrade" pump, which I assume I don't want, correct?

Again, thanks for the help and feedback guys.

 

...

 

look up ep241 on ebay. here is where i got mine.

http://www.ebay.com/itm/NEW-AC-DELCO...ht_1844wt_1270

 

yeah those fittings are a pain the ****. First thing is it the top part of the fitting into the throttle body leaking or where the metal line goes into the fitting? Always put new o rings on the lines going into the fittings. I like to start the lines then mount the throttle body. but yes they are a pain the **** for sure. I am running the 241 pump. i bought it from my local parts store. but other than that I am sure you can find one on the internet somewhere.

 

Thanks! I ordered mine today.

Let's hope I can resolve all the leakage issues.

 

Got the pump Friday, and worked on it for about 4 hours today. I'm still in the middle of things... Fuel pumps suck. I think I can have most everything finished in one more hour, but lying on my back in the dark was getting old, and I have a few extra things I want to do while it's all apart.

I did find out the issue with the old pump. It's locked up. If you give it power, it will "kick" and then lock. The strainer was torn from around the ring, and it looks like there's crap up in there. I think I'll have to give my buddy a call and razz him a bit.

Did I mention I hate fuel pumps? Oh, and I've done quite a few, and this is by FAR the worst.

 

I hate changing them out too. I cut a hole in the back of my car and made a panel for it. Still an hour job but beats dropping rear end and tank out...

 

i really dont see what the big deal on dropping the tank out is. i can have mine out and back in in 4 hours total. no cutting.

 

Different strokes for different folks! it sure was nice when the walbro pump i put in the adapter connector was wired wrong and went negative to positive and vice versa and go to start the car and pump was pumping opposite way. but for the most part it is just being lazy.

 

It lives!!!

 

ha ha undercover just poking you. as for scca junkie good deal.

ok from both of you.

i want to know a lot more on the holley tbi. a lot more. since my 350 in the garage i am building seems to be getting bigger. been thinking about going that route.

 

my advice. holley hp efi whether you want 4 bbl tbi or MPFI. With its self tuning and capabilities to control TCC and other options it is deffinately something I would have went with if I didnt have the stuff I had already.

 

I realized I never did update:

I had no issues with leaks anywhere. I'm hoping that continues (so far so good). Thanks to you guys for help and clarification, as I wouldn't have gone to the TPI pump without your encouragement.

And, as a bonus, the car pulls harder above 4500 rpm. Apparently I was having more of a fueling issue than I thought.

You guys are awesome.

Oh, and one92rs- check out my other thread about the Pro-jection system itself if you want mroe info. I'll be updating that today as well.

 

glad to help! glad you got it done. Yeah my car with a tbi pump would not go past 4000k rpms if I was accelerating from standstill