weird sr20det dying @ WOT problem

[oregondime]

so i just got my 510 back from mckinney motorsports a while ago. been goin through everything, and so far found a few things wrong with it..

thought i fixed everything took it for a drive, ran it through it through the gears WOT off and on for 36 miles. definitely needs tuning. i get off the freeway and get back on goin up the on-ramp, at 5,800rpm it died instantly.. turned it over started back up and died when i blipped the throttle.. the wideband was at around 14 and the spark plugs were a light brown all 4. boost gauge read 5lbs. all temps were perfect.

it seemed as if it got flooded, because 20 minutes later it started up and drove under its own power.

ive looked all over the sr20 forums and havent found anything like this.

heres my specs:

s13 blacktop

stock T25

hks ssqv bov

mckinney intercooler

walbro 255 fuel pump

300zx fuel filter

aem wideband gauge

stock ecu no tune

 

anybody have any ideas?

[slodat]

Call McKinney and ask them to fix it??

[datsunaholic]

Bad TPS? That'd have that symptom.

[b210in]

have you taken readings to see where your fuel pressure is at? was the 14 taken from the wideband at 5800rpm?

[oregondime]

lol cant call mckinney yet just had all 4 wisdom teeth pulled and it hurts to talk so im on 4 days of convalescent leave :) yea it was between 13.5 and 14 right at 5800rpm, but im thinking maybe it doesnt read correctly, they put it about 20-30 inches down the downpipe(is that too far?). when i 1st picked up the car they said they had been trying to get the idle good and i think they said tps too dont remember. probably were having problems with it because i found the wastegate rod wasn't connected after i drove it back on a 3 hour drive.. so i threw a c-clip on there and all was good. havent take fuel pressure reading yet, and will pick up a obd1 scanner when its legal for me to drive lol..

[808DA6]

Few "maybes":

 

1. Failing CAS.

2. Wideband too far downline. On NA apps, 18"s from the collector is recommended (....i think)

3. TPS as mentioned.

4. Ignitor.

 

-Brian

[Icehouse]

Dude my SR has done that before!!! Racing then all of a sudden nothing????? I'm like WTF?? I tried to figure it out but its not like it does it every time. Usually about 1 out of 20 hard pulls it may cut out. I didn't hook any of the tranny sensors up so it can't be the 4th gear cut....

 

 

 

With the stock ECU it should run fine, when I dynoed my sr years ago at 9psi the wideband on the dyno said that my fuel was dead on. So as long as you aren't pushing your engine to far is should be able to adjust itself.

 

Does it kinda pulse when its idling?

 

We want pics!!!! No pics no more questions answered :D

[oregondime]

sorry fell asleep from the prescriptions they gave me, im goin outside to take pics right now :)

it pulses just a lil bit sometimes but usually the idle stays even. lol i was pretty much racing the whole 36 miles it takes to get off base, hit 95 mph and it was fine :) so you never did anything to fix it?

[Icehouse]

sorry fell asleep from the prescriptions they gave me, im goin outside to take pics right now :)

it pulses just a lil bit sometimes but usually the idle stays even. lol i was pretty much racing the whole 36 miles it takes to get off base, hit 95 mph and it was fine :) so you never did anything to fix it?

 

It was so rare when it happened I didn't have any solid evidence to go on. I've also hacked that the harness up so many damn times who knows what could be going wrong.... 3 cars= one fucked harness :D Over all the years I have learned so much more about wiring that I change my mind, redo stuff, add stuff, then forget about other stuff.... I figured when I hooked up the MS I wouldn't have to worry about any of the factory ECU blips, I would have a whole new set to figure out :D

 

Sr's are a bit on the tough side to tame compared to the non turbo engines. Boost leaks, spark plug gap, miss adjusted TPS, timing, even off by the slightest can really fuck shit up on a turbo engine. When they are running right its all worth it but the endeavor is a bitch.

 

What part of the swap did MCkinny do?

[nismopu]

Nissan had a problem in the past with lean/surge conditions on some of their RB/ vg30 ecu's. I have no idea if SR's suffer from the same issues but like you guys are describing it was too random and sparratic for nissan to care about. Arent most of the sr ecu's 16 bit? Seems odd this would be a problem with what alot of the previous 8 bit ecu's suffered from. peace.

[oregondime]

 

 

and a shot of something very badass rollin around on base :)

[oregondime]

sorry about the bad pics, my camera doesnt like this old computer.. yea this was the first time it happened to me.. lol yea ive seen and read alot of what you do, very sweet in the end always ;) well i checked the plugs right after, "0.30 gap, bk6eix plugs. had fixed a significant boost leak that morning, and dunno about timing, will a timing light work with these? and i just started it up and it pulsed for a while like you said but after a few minutes went back to smooth. idles @ 12.9 - 13.1 A/F. the bov is routed this way: line off bov through small filter, over to FPR, throttle body, my boost gauge, then i think 1 other thing.

 

i originally had a ka24de in there, so they pulled that bitch out and did their magic, with a seperate fusebox and relays for the motor. only thing they didnt touch was my fuel pump and crossmember.

 

It was so rare when it happened I didn't have any solid evidence to go on. I've also hacked that the harness up so many damn times who knows what could be going wrong.... 3 cars= one fucked harness :D Over all the years I have learned so much more about wiring that I change my mind, redo stuff, add stuff, then forget about other stuff.... I figured when I hooked up the MS I wouldn't have to worry about any of the factory ECU blips, I would have a whole new set to figure out :D

 

Sr's are a bit on the tough side to tame compared to the non turbo engines. Boost leaks, spark plug gap, miss adjusted TPS, timing, even off by the slightest can really fuck shit up on a turbo engine. When they are running right its all worth it but the endeavor is a bitch.

 

What part of the swap did MCkinny do?

[Icehouse]

Why do they have so many T's on the BOV vacuum line? There are only 3 vacuum lines on the whole engine... FPR, BOV, and waist gate, which shouldn't come off the same T ass the BOV, it should come off the piping close to the turbo. What is the other big fat fuel line size hose doing going in front of the valve cover? Maybe tomorrow you can get some shots with more light :D

[oregondime]

i looked at it closely and the bov definitely doesnt have a dedicated vacuum line.. the one rubber hose in front of the valve cover is the wastegate to TB line, the other is the bov line.

how the bov line is T'd: goes BOV then small filter then the 1st T, (1st T:FPR then goes to 2nd T), then 2nd is to boost gauge then TB. and ive been reading on my hks ssqv, and since its dual chambered it really doesnt need to be recirculated as far as ive read.. its the new version not the old one either.. and the bov is closed at idle

 

and a pick of the dirty ebay carbon fiber hood :)

Edited November 18, 2008 by oregondime

[oregondime]

i finally found one or two other people that had the same problem, so im gonna clean the MAF and replace the new fuel filter with another new fuel filter (maybe the 9 month old fuel wasnt bein friendly), and possibly change out the coilpacks..

 

and! i just remembered, there was a few specks of yellow on the tip of 2 of the spark plugs.. ive never even heard of that

[Icehouse]

You can test the coil packs with a multi meter. Yeah good gas and a clean maf is a really good starting point. Did they run 5/16 lines? what did they do with the tank? It only has one 5/16 line... Not that its that big a deal, I just run the 1/4" as the return and it worked fine.

 

I don't know why they ran the waist gate vacuum line all the way to the intake... do you have a boost gauge? the waist gate should get its reading from the IC piping. So if it hooks to the TB make sure the reading comes from the IC piping side. When I first installed my SR years ago, had the waist gate hooked to the wrong port, I kept wonder why my piping was blowing apart :D Damn those were to good old days :D haha

[oregondime]

even though i wanted a surge tank hooked up they told me i can just do it later, apparently they wanted my car out quickly to make room for mesojdm's old car.. the overflow tank is blocking my view of the fuel lines in the engine bay, but im hoping they just copied how i had it before which was just a simple return line like u said. ive topped off the tank a few times but maybe theres some old gunk in the filter.

 

yep i have a boost gauge, and its on the 2nd T from the bov line, right after the FPR on the intake side. the wastegate line is hooked to the larger right nipple on the TB, is that the correct way? lol how much boost were you running to blow the piping?

[oregondime]

well it happened again tonight, cleaned out the maf and test drove it, this time it sputtered at slow speed and in less then 2 mins it started acting up. got about two miles and it died exactly the same as before. waited and it cranked over for a second, revved it and it died.. then it took 30 mins to get a ride and go get my truck to tow it. when i got there started it again and it drove 20 feet then died.. uggghhh!! everything happened exact same as last time. im thinking maybe the ecu and fuel cutoff or something needs to be reset. or possibly some loose connections?? when i shook out the fuel filter a bit of red came out of it so i guess they never changed the fuel filter or flushed the lines..

[oregondime]

in case anyone was curious to what the dying was.. the CAS completely died. swapped it out and it runs like a champ again!

[Icehouse]

Weird, I wouldn't have guessed that right off the bat.

[oregondime]

lol yea that was the first time mckinney motorsports had ever seen it too.. it was so dead the car wouldnt even start.. absolutely no spark

[Icehouse]

I have ran across one bad CAS but it never worked slightly then failed, it just didn't work at all. I'm just glad its running good.