sr breaks up and misses once warmed up.

[Future_gohan]

So I daily my sr20, and it was good for like a month of daily driving and two events, then i let it sit for a week and almost immediately after it starts missing, so I pull it into the garage find out cylinder 1 is dead. Found out it sparks, and so i put a new fuel injector in it. Then it stopped missing at idle. When i took it for a drive it started breaking up at high rpms.

So I thought maybe it has low fuel pressure, so i replaced the pump with a walbro 255lb, and it didn't change anything, so i checked the plugs and I have bkr7's and they were at .44(I didn't know you had to gap them), and So i lowered the gap to .32 and it seemed to be fine for a wile. But now it's a different symptom.

It does the same stuff, misfires and breaks up, ONLY when the car is at running temp, when it's cold it runs great, pulls threw the whole rpm range etc.

I'm just trying to see if anyone ran into this before, I had a similar issue in my ka-t setup and it was the o2 sensor that was bad. I also checked the timing i'm going to put a new set of plugs in it today and check the coil packs aswell.

Info:
s13sr
stock t25
stock sidemount
cosworth headgasket
cp pistons
greddy rocker arm stoppers
mines tune i'm running 7psi

[jr_ss]

Check your ignitor... Replace if necessary.

[fliprayzin240sx]

Probably a bad water temp sensor since it runs good when cold but turns to shit once warmed up.

[ultimateirving]

Man someone else also had an issue like this. Can't rememebr what happened but there was like small crack in something that created an issue as it warmed up the crack expanded. But seriously check cts its cheap and easy.

[future]

Yeah. Hook it up to a volt meter and heat it up with a lighter. If voltage changes, it works

[Future_gohan]

Okay, Well It seemed to fix itself a few times, so I thought i fixed it. Here is what i have tried so far:

Cleaned maf and intake piping
Changed spark plugs([email protected])
Changed timing multiple times(from 10-20 nothing fixed it, at full advance it was best, but still broke up)
I've checked coil packs, all of them are sparking
I have 21lbs of vac at idle and I've changed my boost around a bunch of times(I have a mines tune for like 12lbs i think i've changed from stock to 10 to 12 and nothing changed at all.
I don't know what would make it intermediate like this, the car was 100% perfect two weeks ago now I've been having nothing but break up issues, I keep replacing everything but I don't have a billion dollars to replace every part on this car. Any ideas??

Also lately it doesn't go away once warmed up, Most of the time it's gone, but I've felt it a few times high rpms 2nd gear.

How would I check my ignitor? Just swap it out?

[zxc4]

make a boost leak tester and inspect it for leaks (I made one for under $10), could be a coupling or cracked vacuum line

[Future_gohan]

make a boost leak tester and inspect it for leaks (I made one for under $10), could be a coupling or cracked vacuum line

Yes, but as i stated it has good vac and it boost's great. I can make one though and test it, it can't hurt.

[jr_ss]

Check the CTS and your ignitor. With the ignitor you can replace it with a known good one or follow the FSM to diagnose it. I wouldn't think it would be your CTS as you'd be running rich all the time.

[Future_gohan]

Just checked the tps, works great, .5 at idle and smoothly increases till wot.

Checked the ohm on the fuel injectors. it clears as good there. I'm getting more frustrated because i cannot figure this out. shit

[cotbu]

What did the spark plugs say? What happened when you tested/swapped the cts?

[Future_gohan]

What did the spark plugs say? What happened when you tested/swapped the cts?

I'm confused what the cts is? The spark plugs were a little white, but perfectly fine operational wise. Nothing broken or out of gap

[Future_gohan]

What ignitors are the same as an sr20? I have a vh in my z and a vg30 sitting here would one of those work?(I haven't checked atm)

Okay, so what coolant temp sensors can i use for the sr20? again i have vg30 and vh45 if they're the same? and a ka most likely

[JSimpson]

94-96 VH45 ignitor works. Could be a coil, ignitor, injector, ecu, low fuel pressure... anything. Get out your multimeter and get to checking

[Future_gohan]

94-96 VH45 ignitor works. Could be a coil, ignitor, injector, ecu, low fuel pressure... anything. Get out your multimeter and get to checking


I did.

It's got good fuel pressure, good injectors, good plugs, good compression, good maf, good tps, no boost leaks, good turbo, the coils fire i haven't checked if any are arking yet it's dark out now and I got a 91 vh so i can't use the ignitor, i'm waiting on changing the ecu out with another one to see if it changes.

[Future_gohan]

So I checked all the coil packs, all have 12 volts to them and all are sparking, ground is fine, i added a ground to the intake to double check, and even rechecked the timing, which at 15* the car hates it, it's worst at stock timing, if i max advance the car it runs best, but still breaks up some...

also none of them are broken or look discolored or any issues what so ever.

[Future_gohan]

Okay, so when i pulled my bkr6e's out there was white deposits on them, all 4. What could that mean? I'm told that means its the incorrect heat range but i'm told bkr6e's at stock boost is OEM. SO WTF mate. I had them gapped at .30 so I'm also told that's fine. I just don't gets it.

[Flushed_S14]

My car did the same thing. It ran fine in the morning but once the motor was warmed up it would miss and back fire.The problem ended up being a coil pack. Maybe one is going bad....When your engine is running fine or cool. Unplug a coil pack and see if thats what it does when its warmed up. If yes...Its a coil pack.

[Future_gohan]

Well it did that for a few days, and then it started doing it all the time, and now its intermediate between hot and cold, I can drive it all day and sometimes it won't do it and sometimes it will, I feel like it's something stupid.


If I had a boost leak, could i still have 20lbs of vac at idle?

[nissansrdub]

my car seems to almost have the same problem with the break up. i was leaning more towards getting a nismo adjustable fpr. i read the walbro 255 may be to much for the stock fpr and not letting it work correctly.

[Future_gohan]

I've worked on so many sr20's that use the stock fpr though, so I don't think just a few setups would be messed up, besides i had a stock pump in this car before and it did the same thing, so it's not pump related.

[Future_gohan]

would it cause my car to break up if the 4 bolt turbo gasket was blown? Just found out mines leaking like a pig

it's all i can find that is wrong with my car, and it's leaking bad, but i can't hear it over my exhaust at all.

[jr_ss]

Yeah, that could be an issue. If your plugs are white, you could be running lean as well. Back the boost dow to 10psi and see if anything changes. I'd also put a wideband on the car to see what your fuel values are at WOT.

[whitey240]

Kind of sounds like you have a tune or ECU issues. I would throw in a stock ECU and see what happens.

Also when you are setting the timing are you going through the whole process and procedure from the FSM to lock in timing?

I have a spare set of coil packs and ignitor if you are interested in borrowing them for testing.

[Future_gohan]

Kind of sounds like you have a tune or ECU issues. I would throw in a stock ECU and see what happens.

Also when you are setting the timing are you going through the whole process and procedure from the FSM to lock in timing?

I have a spare set of coil packs and ignitor if you are interested in borrowing them for testing.


It would be awesome if i could use them, with the car warm and off i unplug the tps start it up rev it 3 times then time it at 15* idle. It seems to be fine atm.

What I did today was at 17* timing and bkr6e's at .023 gap it runs great, but now it idles kinda funky, so i know i'm not out of the clear yet, but I 100% think its a spark issue now

[whitey240]

It would be awesome if i could use them, with the car warm and off i unplug the tps start it up rev it 3 times then time it at 15* idle. It seems to be fine atm.

What I did today was at 17* timing and bkr6e's at .023 gap it runs great, but now it idles kinda funky, so i know i'm not out of the clear yet, but I 100% think its a spark issue now

I am in the North hills just shoot me a pm when you want to come and try the parts.