just installed 550cc injectors car doesnt want to start, but it turns over.

[grnappletree14]

i just recently upgraded my injectors to 550cc, i installed them in my sr20det but when i went over to turn it on all it did was turn over. i never got it to run so far that they are in. does any know why. do i need to tune my ecu or get a safc to make the car turn on or is it something wrong with my wiring because just recently i installed a boost gauge and boost controller while the injectors were getting ship to me, so i dont know what is causing the problem. if any know please help thanks

[Z U L8R]

first. make sure you have the fuel lines on correctly. the hose that comes off of the fuel filter is the fuel feed hose, it feeds the fuel to all the injectors, THEN the fuel goes to the fuel pressure regulator, and the hose coming off the fuel pressure regulator is your fuel return line back to the tank (there's no filter on that line). i say this because even though your cars gonna run rich as hell...it should still start. second. yes you need an safc or some other way to adjust the air/fuel ratios because now you're dumping almost twice as much fuel. if you MUST drive the car, don't boost it, cause you'll foul your plugs out very quickly. for the money, get an safc2 and spend $100-150 to get it dyno-tuned. and if you got the cash get a 300zx maf while you're at it that way when you're getting it tuned and turning up the boost, you won't be limited to 260-270ish horse because of the stock sr maf. if you're still running the t25, you prolly should have waited to put the injectors in, but if you have a t28 or something similar 15psi should put you around 250-260 horse depending on your tuner. stuff like tuning you should definately NOT be stingy with the money on. if you don't spend the money to tune it, i will kill you till you die from it =]
good luck

[kidswole]

hey i bought some 550's from venom and they were garbage. dont remember if you said you an ecu tune of not but if you didnt have it tuned for 550's it should still run (not very good) and if you had an ecu flashed then they could have screwed up. happened to me the first time i had one flashed.

[longdy]

welll its seems that there are either a couple of things that you have not done right!!

1. just like ^ was saying maybe the fuel lines are put on incorrectly and was flipped around.

2. check to see if you have any pressure build up from the fuel pump and also check to see if it still holds pressure. this was a problem for me one time.

3. check to see if your ignitor chip is clip in properly for some reason when my car was acting like this when my 555cc Nismo injectors were in, it was the ignitor chip that was kind of messed up so it would turn and turn but no start.

try these first and if it still doesnt start up post again!!!!

good luck dude:rawk:

[Z U L8R]

ya, besides the fuel lines being backwards, the only other thing i can think of is the two o-rings on each injector. if those aren't there, on correctly, or not sealing properly, it's gonna POUR fuel into the cylinder, flood the cylinder, and/or hydro statically lock the motor (the cylinder is filled with fluid and the piston can't travel up because there's fluid in the way)

[Silverbullet]

once you get the car to run, go and invest in a Z32 MAF and a ROM tuned ECU for those injectors. You CAN adjust it with an SAFC however its not the best option espeically for injectors that much bigger than your stock ones. SAFC FTL unless its fine tuning after u have a ROM tuned ECU.

[Justin Bernstein]

Simple answer to a probably more complex question but when I began messing with my fuel pump/injectors/regulator I was running so rich that it instantly ruined my spark plugs. Try swapping them and adjusting the fuel pressure down. Maybe this way it wont flood the injectors.

[RYAN_S-14]

and for the wiring there is no polarity in fuel injector wiring, so you can really mess up the wiring, I always try to keep it the same accross the board

[statik]

i never got it to run so far that they are in. does any know why. do i need to tune my ecu or get a safc to make the car turn on

:ugh:

its pretty obvious he installed larger injectors with nothing to compensate for them...im sure your wiring is fine, you are just flooding the crap out of your engine. Also when you install injectors make sure to lube the crap out of the o-rings before installing them (vasoline/petroleum jelly works well)

[grnappletree14]

if i did flodded how can i tell and how can i fix it.

[statik]

if i did flodded how can i tell and how can i fix it.

Your running larger injectors, the ecu tells the injectors to spit out n% amount of fuel, but those numbers on a stock ecu are meant for stock sizes injectors. Now you put in larger injectors, and the ecu still says put out the same n%, except your injectors are larger than stock, thus you are putting out extra fuel.

I suppose it may start with those injectors on a stock ecu with no correction but you will run stupid rich, as stated, other things to check for are reversing the fuel lines, make sure the line coming off the fuel filter is going to the back of the rail near the firewall. Also did you install the o-rings properly and lube them up? If you didnt and you tore an o-ring then you are dumping even more fuel.

Pull the plugs, im sure they are soaked with fuel, if you want to burn it off you could disconnect the cas and crank the car a bit or pull the fuel pump fuse and crank it with the throttle open till it turns over and then dies (no more fuel coming in), I would honestly put the stock injectors back in. You clearly don't know what you are doing, get a rom tune, or at least an safc. Get a z32 maf, though its not necessary to make the car run with larger injectors, but without it the injectors are pretty useless since the stock maf is limited to ~270whp. Once you have someway to control the larger injectors, put them in.

[grnappletree14]

im buying a safc today so when i get it im going to install that with my q45 maf. i just was curious y was it starting, becuase i bought these off of someone and i thought that he might of sold me some broken ones. so yea im going wait to latter to see the problem. thanks everyone for all the help

[EnthusiastMan]

The car WILL run with a stock ECU. I know because my previously tuned ECU craped out and I had to buy a stock ECU to try. It ran, but damn did it run rich. I also have 550's.

[DJ_Sunrise]

simple answer. 550 divided by 370 = tada! that many times more fuel than before. you're lucky if the car starts. of course it wont run after a couple times, u will foul everything out. unflood the engine before you blow/wear the piston rings.. make sure the cars not sitting around for too long like this, otherwise it could happen. <-- identical to when you compression test an engine.. you're supposed to pull the fuse for the fuel pump, and release pressure from the gas tank. uncombusted fuel in cylinders = big no no. replace the plugs and o2 sensor, more than likely they're shot. and yes, u do need some form of correction, big time. no, SAFC is not the answer :). its just a cover up. :down:

[grnappletree14]

yea i got it to run today. i had to unplug the cas and crack the enigne over. then i put my spark plugs right in and pluged every thing back in and i started it up. the only thing now it runs rich but also it doesnt let me go past 4000 rpm without bogging. so every time i have to shift at 3500 rpm to make it run smooth. it runs smooth but it doesnt let me go past that certain point. on the boost guage it show that i have a vacumn leak because the vaucumn read at 10-20 it depends. i also moved my timing around that caused the vacumn to run high so i had to adjust it. will the injectors make my car bog at 4000 rpm or is it a vacumn prob. also i was just woundering if i should buy a safc, will that make my car run way better. or should i just tune my ecu.

[kognition]

A good mechanic in your area? I wouldn't waste my time if did not know what the problem was. Learn it from the mechanic. You will be amazed. Money well spent.

[statik]

i have a vacumn leak because the vaucumn read at 10-20 it depends. i also moved my timing around that caused the vacumn to run high so i had to adjust it.

get a boost leak tester or make one, and i really hope you know how to set the timing properly...