3800 When I put in the performance fuel pump

[LP 3800]

According to the scanmaster, my injectors are working hard to keep up with the gas that I need. I am installing a walbro fuel pump this week. Will that push more gas out of the injectors?

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[alexgtp]

I think if you are static with the injectors it is time for injectors.
All the pump does is pour more fuel per/sec. SO your injectors would still be the bottleneck.

Or maybe i am totally wrong

 

[BLK00GTP]

Im pretty sure your right Alex. All the fuel pump does is deliever the fuel to the fuel rails faster but you will have to upgrade rails and injectors i believe because they have a (lbs.) rating. Im pretty sure thats how it works.

 

[LP 3800]

Unfortunately I also think you guys are right. Here we come injectors!
Thanks for your help guys

 

[sweetness]

Definitely get the injectors. With more fuel pressure you may be able to go a little longer without them, but eventually your choice will be a couple hundred for injectors or a few grand for an engine.

 

[J.E.T.]

Hmmm, did you get to read the Thrasher post on injectors? Darn, I think its on the old site. Very informative. I think its on the Thrasher site too... let me see.

Here's the qoute:

The production injector for all L67 engines is calibrated from the factory as a 36 lb/hour (4.6 g/sec) injector.  A very rough formula to determine the power level a injector can support is simply to divide the total flowrate of all the injectors (6 in this case) by the BSFC (Brake Specific Fuel Consumption).  If we conservatively estimate our BSFC at an inefficient 0.6 lb/hr/HP, six 36 lb/hr injectors will provide 216 lb/hr of total flow, so this indicates they can support up to 360 HP.  A more realistic BSFC is 0.5 lb/hr/HP (our engines are a bit more efficient than 0.6!), which indicates our stock injectors can support up to 432 HP!  Actual engine dyno testing has shown that the BSFC of our engines is between 0.35 and 0.4, meaning the stock 36 lb/hr (4.6 g/sec) injectors can theoretically support between 540 to 617 HP!

I had a hard time deciding whether to upgrade my fp or injectors. Ended up upgrading my pump first because of several factors:
- Cost me less to find out if it solves my leaning up top problem.
- Advised by members to try the fp first.
- My fp is the orig - might as well replace it for preventive maintenance.
- The worse that could happen is I also get new injectors to work with my new fp.


LP3800: The IC AC uses the stock fuel rails?

J.E.T.
'97 Red GTP

 

[J.E.T.]

LP3800: You'll probably need to upgrade the FP AND injectors. You're cammed, AC IC, 2.8 pulley... I don't think any of the big boys run stock injectors...

Justin: How much for a set of 38lbs?

J.E.T.
'97 Red GTP

 

[LP 3800]

Thanks for the info. The AC IC leaves the rails up to you, for now. I will end up getting some real ones soon.
Do you think that 38LB will do it? I don't want to change them again, nor do I want one's that are too big. How much for some 38LB'ers? I need them soon.

 

[Royalgtp]

I thought our next choice was 42 lb.???

also, how do you adjust if you have to much fuel? ICCU, mini AFC, etc?
I was wondering about this.

 

[imported_Ron Vogel]

38's are better, but 42's are cheaper.

 

[CoolGTX]

Originally posted by Ron Vogel@Dec 8 2003, 04:02 PM
38's are better, but 42's are cheaper.

why would 38s be better choice? For as far as he is going to mod, id think 42s, because you only want to do it once(at least I do), im poor ass.

DHP, can and will programm for the larger injectors, which is the CORRECT way to do it.

 

[superchargedgp]

LP3800 call me tomorrow i need to tell you something about WALBRO pump

call me ASAP

 

[gtphale]

Feul pump will keep your injectors from going static on you,hard to tell for how long though. I have gone to the 42.5's and so far have good luck with them. Need to get the puter programmed for them still. But have other issues i'm dealing with and just don't have the time to work on car right now.. Thrasher's cage car is supposedly running stock injectors and a walbro pump so it will help.Get the 42.5's your going to need them.

 

[LP 3800]

I will get the 42.5's...soon. The next thing I buy(after my car is pumping again) is the input shaft. I think we all know that mine is going soon and I do not want another tow story in the near future. I will talk to Miker for that one and see how his new shaft is going.

 

[J.E.T.]

LP3800 call me tomorrow i need to tell you something about WALBRO pump

Don't be afraid to post it here for Pete's sake. I don't think anyone will bash what you have to say... Maybe we could all learn something...

J.E.T.
'97 Red GTP

 

[superchargedgp]

WALBRO SUCKS ASS lol or my mechanic skills


having fuel pressure problems