car starts but dies immediately - running out of ideas

[go240]

i did some changes to my redtop this winter - here's a rundown of the important ones:
cometic hg
arp headstuds
hks 264 step 1 cams
RAS
t3/t4
tial 38mm
650cc deatschwerk injectors
deatschwerk fuel pump hardwire kit
sard fpr
apexi power fc

now the car will fire (it sounds fine - all 4 cylinders, no missfires) but it dies almost immediately. the fuel pump shuts off after the car dies, so i don't think its that. it's not the MAF - disconnected it and it did the same thing. it's not the CAS, i moved it 180 degrees and it wouldn't even start so i put it back. my fuel pressure is set in the low 40psi range. i don't think it's a vac leak either - i put an extra boost gauge into the bov line and it goes down to -15 or so psi before it dies - if i disconnect a line it dies before it even gets to -5 psi. the tps is fine - the voltage is correct and changes as the pedal is depressed.
the pfc has been set for the z32 MAF and for the 650's (lagtime has not been set, i messed with it a bit but it made no difference)

i'm running out of ideas here. the car will run a little better the longer it sits between tries. it dies faster if you start with the gas pedal slightly depressed. if the car starts and you hit the pedal, nothing happens (probably because it dies right awayy)

thoughts? i just want to :2f2f: to the dyno

[go240]

i wonder if the plugs (NGK heatrange 7 iridiums) are getting fouled with too much fuel - but it doesn't smell flooded, so maybe not.

[flamebag16]

alternator maybe just an idea heard somewher start ur car and unplug the battery while its on if the car dies its ur altenator

[go240]

alternator maybe just an idea heard somewher start ur car and unplug the battery while its on if the car dies its ur altenator
well i have my small sealed battery jumped to a fullsized boat battery that's hooked into an a/c charger

[go240]

does anyone have lagtime data for deatschwerk injectors? i emailed them, so hopefully i'll have those numbers next week. and would lagtime really keep the car from idling?

[smithers584]

ok well if i read correctly, you said that your engine does the same thing when you unplug your MAFS. I think you should look into that some more if you havent already. I know when i first did my swap i tried starting without my maf, and thats what happened exactly. could it be a power FC problem? I dont know shit about those but you could go back to your stock fuel map and try that. Possibly could be an idle air control valve, hard to say though. you could also check your power and ground to your ecu.

[smithers584]

you also said your put your cams in, you sure your timing is right?

[go240]

ok well if i read correctly, you said that your engine does the same thing when you unplug your MAFS. I think you should look into that some more if you havent already. I know when i first did my swap i tried starting without my maf, and thats what happened exactly.
hmmm, people have said it should start without the MAF unplugged. and now that i think about it, i've blown ic pipes before and the car hasn't died, just spewed black smoke and run rough

[go240]

you also said your put your cams in, you sure your timing is right?
timing has been checked so many times, i'm fairly postive its right. i tried going 360 on the crank (180 on the CAS) and then it wouldn't start at all, so i put it back. and i'm very sure the cams are aligned right - i spent so long looking at that, counting chain links, etc.

[smithers584]

your right your car should start without your MAFS connected, but if you have any type of vacum leak the combination of the two would cause it to die. you said your gauge is reading like 15, i am pretty sure sr's are suppose to read around the 20 range.

[go240]

your right your car should start without your MAFS connected, but if you have any type of vacum leak the combination of the two would cause it to die. you said your gauge is reading like 15, i am pretty sure sr's are suppose to read around the 20 range.
yea, but its still going down when it dies - (i don't think it runs long enough to develop full vac. fires and dies). and if i disconnect a line it is noticeably different - basically won't even fire

[go240]

do you know of a better way of checking for vac leaks? i'm pretty sure that's not it because it would have to be a fairly large leak to keep it from idling (and if it can get to 15 psi and more before it dies, i just don't see a vac leak as the culprit).

i'm going to try a friends tomei 555cc injectors because we know they work and we know the lagtime. that will hopefully either fix it or i'll be able to rule out injectors

[smithers584]

do you have a leak tester? i just wrote a thread about how to make one if not. i would try it. basically you are saying everything is good but the car still dies, so its time to start double checking stuff you know. i hate these kinds of probelms.

[go240]

do you have a leak tester? i just wrote a thread about how to make one if not. i would try it. basically you are saying everything is good but the car still dies, so its time to start double checking stuff you know. i hate these kinds of probelms.
well i pretty much took an extra boost gauge i had and tied it into the bov line.

link to the thread on the leak tester?

once i get the injector lagtime set correctly i'll start going over things again. i might try switching to copper plugs and gapping them tighter

[smithers584]

here is the link: http://www.zilvia.net/f/showthread.php?t=106184
the nice thing about the home made tester is that the motor wont be running or anything, so you will have plenty of time to find a leak before it dies. youll see, youll need an air compressor to use it though.

plugs shouldnt be the issue at all as far as copper or iridium, i just hear that the iridium arent really worth the extra cost. Im sure you know .028 to .032. most people like the smaller of the two, i run .032 and it works great. If you do switch, just make sure you change them about every oil change.

[go240]

i've heard not to gap iridium plugs - that the tips will crack

thanks for the link - i'll try that out

i also just learned that in the etc. menu under sensors/functions if an item is highlighted, that means theres a problem with it. i remember 1 or 2 items were highlighted on mine (i'm gonna call my dad tomorrow to have him turn the car on and tell me what they are)

[smithers584]

not sure about the plugs, i just know that nobody i know that has bought them has liked them anymore then the copper bkr7e's. Copper seems to be the choice for almost everyone on this forum. let us know what you find if you do, im interested.

[go240]

the MAF value is highlighted on the pfc. it didn't change after cleaning it and trying a few more times. i'm not at home, but my dad was kind enough to go get a new MAF to try in the car. hopefully that fixes it

[NIK90s13]

here is the link: http://www.zilvia.net/f/showthread.php?t=106184
the nice thing about the home made tester is that the motor wont be running or anything, so you will have plenty of time to find a leak before it dies. youll see, youll need an air compressor to use it though.

plugs shouldnt be the issue at all as far as copper or iridium, i just hear that the iridium arent really worth the extra cost. Im sure you know .028 to .032. most people like the smaller of the two, i run .032 and it works great. If you do switch, just make sure you change them about every oil change.


Hey Smithers! Any way, to ad to Smithers, you can go low tech and use a hand pump to pressurize for vacume leaks if a compressure is not avalible.
And if the plugs were bad it shouldnt start at all.

[mbmbmb23]

Fuel filter installed backwards or lines reversed? I would undo a fuel line and see if gas is forcefully pumped out when the ignition is on.....route the gas away from the car obviously.

-m

[go240]

Fuel filter installed backwards or lines reversed? I would undo a fuel line and see if gas is forcefully pumped out when the ignition is on.....route the gas away from the car obviously.

-m
no and no. i wish i was retarded like that, but you tend to learn from your mistakes (when i did the swap a year ago i had the lines crossed).

[smithers584]

ok well if i read correctly, you said that your engine does the same thing when you unplug your MAFS. I think you should look into that some more if you havent already.

if this works you owe me some rep points! j/k, hopefully it does, shitty problems like this you just have to try just about everything, sucks. if swapping the maf doesnt work, check operating voltage per FSM. I want to say its something like .9 volts-1.4v at idle, and then 1.5-2 at 3000rpm. you might wanna double check with the FSM. check the maf grounds also.

hey Nik90s13, im all over the place! just trying to help, i went through tons of learning first hand cause i live in South Carolina, so nobody here speaks turbo language, you have to be a redneck with a v8 w/ exhaust then brag about how fast it is! hahaha they arent to friendly when they get there as handed to them by a 2.0!

[go240]

yea, my friend said his pfc reads 850mv with the key at on. mine reads 20mv haha.

[smithers584]

hhhhhmmmmmmmmm


j/k, just being a smartass dude! hope it works out for ya, keep us updated.

[go240]

yea i bought a new one. but it could be in the wiring (wish i still had a multimeter so i could test resistance)

[go240]

well it was really simple. i sat down and thought about what wiring changes i did to the car over the winter. the only thing that seemed to be MAF related was that i removed my old safcII - of course i never reconnected the MAF wire that was intercepted by the safcII.... DUH! i'm a dumbass - whoo hoo!!!

so now the car runs alright. revs up to 2k, drops down, bounces around and eventually dies after a few minutes. time to re-initialize the power fc and let it perform the self-learning idle again (got all confused from me starting it over and over without a MAF signal i think)