pauly383
Daddy383
If you want to spend a 285 bucks , Quick Fuel makes a piston pump that will bolt in place of the stock motor driven pump , and work for fuel injection 
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
Fuel pump for TBI conversion
- Thread starter bp71k5
- Start date
A Bosch 69100 or Airtex E2000 works quite well and they don't have to be mounted below fuel level. Use a 80- 100 micron screen on the inlet to keep the big stuff out. The original sock will work fine as long as it is in good shape. Don't install a regular fuel filter before an inline pump because they will restrict inlet flow and ruin the pump especially when the filter gets a little bit of dirt in it. Install a high pressure style filter after the pump to protect the injectors.
bp71k5
3/4 ton status
That fuel pump might actually be a good option, but kinda pricey. Does the pushrod for the mechanical pumps run off the cam or the crank? I've got a "TBI friendly" cam in there and I'd want to make sure it'll even run a mechanical pump. Thanks for the tip Pauly!
I'm sure you have reasoning for this. But I have seen literally thousands of inline pumps running filter before pump with no ill effects. I have always ran two filters when doing a conversion, one before pump, one after pump. Although many do not run a second filter after the pump and still no ill effects.
If your going to run an inline filter before the pump take the sock out of the gas tank and clean the gas tank. It'll work fine.
I have also run a couple of these pumps after a mechanical pump in the engine compartment with no ill effects. Steady fuel pressure. Many miles. May not work well on more than about 250 HP.
pauly383
Daddy383
The Quick Fuel pumps boplt right to the block and require 25 pounds of force from motor , so its a no brainer if you got the cash .
All cams through at least the end of TBI had an eccentric and the fuel pump boss drilled and ready .
When the Vortecs came I dunno . Sooner or later we will wreck our 99 Sub , and I get to take a Vortec apart
The Quick Fuel pumps boplt right to the block and require 25 pounds of force from motor , so its a no brainer if you got the cash .
All cams through at least the end of TBI had an eccentric and the fuel pump boss drilled and ready .
When the Vortecs came I dunno . Sooner or later we will wreck our 99 Sub , and I get to take a Vortec apart
So far i haven't seen a cam without the fuel pump lobe, however i have seen a couple pre 1996 engines that were not drilled for the fuel pump pushrod.
My vortec block (unsure of year) has no block off plate but the boss for a fuel pump.
My guess is it's an easy drilling job to convert to mech. pump.
Scott, are you saying even the Vortec motors had a fuel pump eccentric??
My guess is it's an easy drilling job to convert to mech. pump.
Scott, are you saying even the Vortec motors had a fuel pump eccentric??
I have no idea on the vortec engines, but every engine 1995 and earlier have it.
Also it would not be an easy job to drill for the fuel pump pushrod. The hole must be a precise fit and at the correct location and angle. The only way you would be successful is if you were doing it in a mill and knew the exact location. I have also seen 1995 and earlier blocks that had the boss for the fuel pump but had no pushrod hole drilled. Obviously they were a TBI block (87-95).
I ASSuMEd that the hole was at least partially started, so you could simply finish it up with the proper drill. I guess it doesn't matter when you are casting.machining them for a finished product. Never turned the engine on it's side to look.
- Joined
- Mar 3, 2000
- Posts
- 9,123
- Reaction score
- 7,077
My 93 TBI motor out of a suburban has a blank boss no hole for fuel pump rod.
Thunder
3/4 ton status
I dont know why anyone would want to spend almost $300. Plus another $60.00 or so for a regulator. On a mechanical pump for TBI. When you can get an electric one that does the same thing for 80.00?
bp71k5
3/4 ton status
I've actually seen one on a few web sites for $170 which is just a few bucks more than the electric. The only reason I'd consider it would be that I assume the mech pump is better at sucking the fuel out of the tank and would be able to recover better if the fuel in the tank gets sloshed around away from the pickup tube. I'm still checking on those assmptions.
pauly383
Daddy383
I a
1. People who want it to look like a regular motor when you pop the hood and see chrome valve covers and chrome air cleaner .
2. Racers .
3. Those of us like me who want to be different , and not deal with a non rebuildable pump when it dies . This one can be field stripped and fixed .
Price is an issue , which is why I have a carburetor ( I am piecing together a TBI setup myself now , slowly ) ( and I own two injected rigs already ) , but if I could afford this , I would do it in a heartbeat and carry a very light rebuild kit .
I dont know why anyone would want to spend almost $300. Plus another $60.00 or so for a regulator. On a mechanical pump for TBI. When you can get an electric one that does the same thing for 80.00?
1. People who want it to look like a regular motor when you pop the hood and see chrome valve covers and chrome air cleaner .
2. Racers .
3. Those of us like me who want to be different , and not deal with a non rebuildable pump when it dies . This one can be field stripped and fixed .
Price is an issue , which is why I have a carburetor ( I am piecing together a TBI setup myself now , slowly ) ( and I own two injected rigs already ) , but if I could afford this , I would do it in a heartbeat and carry a very light rebuild kit .
mr_blasto
1/2 ton status
So maybe I was totally misinformed, but... I just put in a TBI system from affordable fuel injection on my '72. Their install instructions said to put the in-line fuel pump lower than the tank (as mentioned) OR after a mechanical fuel pump, but in either case to put the fuel filter before the in-line electric pump.
Granted I only have about 50 miles on the setup, but my fuel line is stock from the pick-up in the tank to the mechanical pump, but after the mechanical pump it goes to a fuel filter, then to an electric pump, then to the throttle body. Seems this setup would work for you too, unless there is something really bad about running the system this way (in which case someone please let me know).
Granted I only have about 50 miles on the setup, but my fuel line is stock from the pick-up in the tank to the mechanical pump, but after the mechanical pump it goes to a fuel filter, then to an electric pump, then to the throttle body. Seems this setup would work for you too, unless there is something really bad about running the system this way (in which case someone please let me know).
bp71k5
3/4 ton status
So your saying you have an electric pump and filter between the stock fuel pump mounted on the engine block and the throttle body? Can I see a picture by any chance?
Thunder
3/4 ton status
You also need a adjustable regulator too. So add that to the price.
You still have to run a regulator before the TB with a mechancal pump.
The TBI regulator MUST have a steady flow that does not pulse. The pulsations from a mechanical pump will drive the regulator in the TBI nuts. So you need an additional FPR to smooth out the flow.
I dont know where you are getting prices for pumps. But you can get a Walbro inline 225 LPH pump that will support 500 HP for $120.
Rebuild a mechanical pump on the trail??? Sounds like a friggin hassle to me. It is a very simple matter to carry a spare electric pump and install it in a few minutes.
I bet the kit to rebuild that mechanical quick pump costs more than an electric pump.
As far as fuel slosh goes.. Just run the fuel return next to the pump pickup in the tank and you wont have a problem.
They run fine this way, up until 200-250 hp and it's easy. Check the fuel pressure at all RPM. If for some reason it does not work then you will need to mount the electric back by the tank and have high pressure line from the pump to TBI unit.
The p5001 pump will work three feet from the tank and a foot from the bottom of the tank! No sock, metal filter, good 3/8 line! Yes it will!
Other cheap POS pump with 1/4 lines won't.
When using the mechanical pump try to have the output 3/8, then give it a big high pressure filter, then more 3/8 to the TBI unit.
I've never seen a mechanical pump made for EFI operate, or seen what kind of steady pressures it will run at what RPMs? But then again why re-invent the fuel delivery for EFI? Electric pumps that are designed for EFI are to easy and cheap...
mr_blasto
1/2 ton status
Too wet to get some pics right now, but from the mechanical pump on the block fuel goes to the filter and then the electric pump mounted on the fenderwell and finally to the throttle body. I will try to get some pics tomorrow. Again, I dunno if this is kosher or not.
mr_blasto
1/2 ton status
Why won't this work beyond 250hp, and what can you do to make it work?
I agree with thunder on everything he said. I'll also add that it may take a pulsation damper to get a consistent enough pressure to get a TBI or any other injection system to run right. Some EFI systems use a fuel pressure sensor which could compensate for pressure variations.
Electric inline pumps are way too cheap and easy to make work to fight a mechanical pump. Fuel slosh is not a problem above a 1/4 tank, even in extreme angles.
I will try and further clarify the fuel filter issue. A regular fuel filter will work in front of an inline pump but it will cause problems sooner or later. Any amount of dirt in the pre-pump filter restrict the fuel into the pump enough that it will cavitate the pump causing low fuel pressure at high engine loads (the more power the bigger the problem) and will quickly ruin the pump. You can work around this problem if you can change filters often.....very often. A simple 80ish micron filter or sock alleviates the problem and makes the pump a lot happier and have a lot less chance of failure out in the middle of nowhere.
Electric inline pumps are way too cheap and easy to make work to fight a mechanical pump. Fuel slosh is not a problem above a 1/4 tank, even in extreme angles.
I will try and further clarify the fuel filter issue. A regular fuel filter will work in front of an inline pump but it will cause problems sooner or later. Any amount of dirt in the pre-pump filter restrict the fuel into the pump enough that it will cavitate the pump causing low fuel pressure at high engine loads (the more power the bigger the problem) and will quickly ruin the pump. You can work around this problem if you can change filters often.....very often. A simple 80ish micron filter or sock alleviates the problem and makes the pump a lot happier and have a lot less chance of failure out in the middle of nowhere.
