Fuel pump pressure??

hello there again everyone...

i have another quick question....... i put a pressure gage on my fuel line .......i cut the line right after the fuel filter just to see what the pump was puttin out and i got around 40 psi ....and while the pump was holding about 40 psi i turned the pump on again and it shot up to 80 psi.

I was just wonderin if the pump should be pumpin 80 psi right from the get go ...?????.....i know thats what there rated at ...does this mean that my pump is bad....because my car has been reallllllllllly hard to start...and once it gets warm it stays started ..


THANKS AGAIN!!!!!!

IM ABOUT TO GO :eek7: :banghead:

a 5sfe should have a base FP of 36..... 80 is EXTREMELY high... thats probably part of your problem if not your problem

Is that inside the fuel rail ???........because i cut the incomeing fuel line thats goin into the fuel rail and just put a gage on the end ....im tryin to find the fuel pump total pressure..... to see if its bad....

thanks

whyed u cut the line?!?!?! just pull the main fuel line coming off the fuel pump and attach the guage there, it should red about 36 psi

if a stock Fuel pump has a top PSI rating at 70 psi then the pump should pump to 70 psi ....i get my info from a new fuel pump from napa

Link http://www.napaonline.com/cgi-bin/ncommerce3/ExecMacro/NAPAonline/search_results_product_detail.d2w/report?prrfnbr=15547201&prmenbr=5806&usrcommgrpid=63890136

Whats happing is when i try to start my car i turn the key to on.. and the pump starts running then i try to start the car.....it runs for about 1 second....then it just cranks ...i do that over and over again until it finnaly starts.....but if i turn the key on and off "X" amount of times it runs for longer period of time like 4 seconds and stops ......

so i have come to the conclusion that the fuel pump is only gettin that 40 PSI into the rail the first time i crank and then the PSI is falling off so the car doesent start...until i do it again.... ALSO when the car does start for that breef second the Fuel pressure reg kicks in and alows fuel to bypass the rail back to the tank ...........

im just tryin to see if that sounds right to you guys

i know that the fuel rail has to have at least 44 psi to run

thanks again guys

um no the main FP pressure should be 36, anything over that is suicide, ask jeff in the mr2 froums, he runs his mr2 at 42 psi and thats only to get more boost outta it

If you have a pump ....of anykind... We will say a water sump pump rated for 115 psi for shits and giggles... when you hook a hose on the end of the pump, and at the end of the hose ther is a psi gage... when you drop the pump into the water and turn the pump on it will read the maximum psi that that pump can put out, it should be around the 115 psi mark...then the pump will keep running and push no more water because it cant...........

this is the same test that im trying to do on my pump

i understand that in order to have the a 1990 celica gts running right that the fuel pump, fuel line, fuel filter, fuel rail, fuel pressure regulator, and return fuel line has to be at the total 39 psi.....but thats not what im checking .....

thanks..

then what are u dtrying to check? be a lil more specific

im just tryin to find out if my pump is bad......but i guess i answerd my own question.....haha....

another thing to consider is the fact that i changed my 5sfe to a JDM 3sge

the 5sfe was a bit on the blink.....after my bro :loser: had the thing smoking...HAHA ....and after i replaced all the melted plug wires, Cap and other stuff......the 150k mile 5sfe dident start right ....the same problem i am haveing now....so i just bought a JDM 2nd gen 3sge with 45k on it for $165 and put it in

i personaly think that the fuel pump is bad because i ruled out every else ..... i just wanted to get everyones opinion...

thanks

haha yeha bro that woulda been a little more helpfull... ?'s

1. did you use your existing wiering harness
2.how long ago did u do the swap/has it ever ran right?
3. are uusing the 5sfe or 3sge fuel pump

well i am using the same fuel pump that came with the car 150K miles on it

I am also useing the wireing harness that came with the engine and the JDM ECU 3s-ge M/T

I have done the swap about 8 months ago ..worked on it every other weekend....never ran right.....

well my thought prossess went like this....

......New engine with more power that i can turbo later $165...

$200 fuel pump on a engine that i dont think is ever gonna run right again....


so i got the engine...haha i think it was worth it

i can already tell you....have you re chipped the ecu? u know that s its meant to have 100 Ocante right? it probably thinks its not getting anough fiel so its upping your base FP and thast was making it idel like shit

yea i found that out when i was looking for info on JDM engines......so i put about 5 gal of 93 octane in and added one full can of 104 octane booster ....hahaha....im hopeing that thats ruleing that situation out

tonight im making up an inline fuel pressure gage and seeing if my FP is droping off ater i crank it over ......im hoping that it does because i just bought an $ .99 fuel pump on ebay haha

yeah im guessing thats your problem, your probably either starving your fuel pump or its bad....what fuel pump did u use? please dont say the 5sfe one

well i have found out that my fuel pump is ok and now im just gonna bang my head off a iron post :banghead: ......i mean its just silly!!!!

after i get the car warm it runs good.... but its just the cold start thing... i am at a loss ....is there anything else i could be missing??..

i have a 4 wire o2 sensor that could be the prob ...????

i dont know....