View Full Version : S13 with SR20DET big problems please help

09-27-2013, 02:17 AM
Hello guys.
I encountered a problem with my sr.
I have a S13 with SR20DET under the hood.
Stock turbo.
3" exhaust.
Big intercooler.
Walbro fuel pump.
Stock engine with HDEV stage 1 ecu upgrade.
The car used to run very good at 14psi boost.
Now the problem is that it stopped pulling due to fact that the boost is still 14psi. .
And it detonates at high rev's.
I tried with other coils and it's the same.
And is going a bit rough when I pass 5 psi.
Anyone can help pls.
Thanks guys.

do it sideways
09-27-2013, 09:08 AM
Check for boost leaks first, as it's most likely that. Possibly timing or tune?

09-27-2013, 09:12 AM
Stock SR is going to detonate its ass off at 14psi. There is nothing you can do, other than add bigger injectors and have it tuned.

Check for boost leaks, change the spark plugs & DO NOT use octane booster or fuel additives.

09-28-2013, 12:37 AM
Fuel mapping issue/ need bigger injectors because your leaning them out at 14psi. And you need to make sure there are no boost leaks. Make sure you're getting a good MAF signal. Try running a colder plug. Research you'll find posted part #'s. Check timing

09-28-2013, 12:40 AM
Also, did you change/add anything before this detonation issue. Did you have the ecu installed before?

09-28-2013, 01:52 AM
The car used to run very good with this setup.
I did nothing until it stoped pulling
Now it's going "rough" (has no smoothness)
I already replaced the spark plugs, checked for boost leaks(nothing), and replaced the coils.
Tried to run without BOV, the same.
I also pulled the plug from lambda sensor and maf (one at the time) and it's running very bad without any of them.
A few weeks ago when the car was runing fine, there were no "detonations" in the exhaust.
A intresting thing is now that after some short run's I can smell gas inside.

09-28-2013, 02:09 AM
I think your wording may be incorrect.. detonation usually means the car is running lean. From your description, it sounds like it is running overly rich, causing it to miss and backfire out the exhaust.

You may have a leaky or bad injector. Also check the condition and replace all your spark plugs (setting to proper gap). If you have one bad injector, the plug on that cylinder will be black / much darker than the rest, or wet. You can also test the resistance of the injector to ensure its within spec.

If all spark plugs seem the same condition, replace all and see if it persists or if it helps.. it may be an ignition issue then.

09-28-2013, 07:11 AM
Is it not pulling? Clutch going out on you?

09-28-2013, 03:14 PM
It's not the clutch.
It has hesitation when I pass 5 psi. It still pulls but has an hesitation.
I allready replaced the spark plugs, the coils, the igniter, all vacum lines, fuel pump. It's strange because it had no problem until last week. And I changed nothing since then.

09-28-2013, 04:01 PM
I would say it's a bad injector. Hook up a wideband an check what your afr's are at.

09-29-2013, 06:36 PM
Check your voltage and be sure you have 12v and more at fuel pump

09-30-2013, 12:05 AM
Thank's very much for the help guys.
So far I replaced the spark plugs. The color it's the same on all (brown).
Replaced also the igniter.
Checked the alternator output voltage and it's ok (13.8 on idle)
Connected some grounds from engine to chassis.
The car now it's running better but still not as it is to run.
Today I will install a wideband to check the afr.
I'm not sure what the afr should be (12 or richer at fool boost ?)
I will also borrow a Maf to check out.
Can it be also the lambda sensor ?
I'm also thinking replacing the fpr.

09-30-2013, 07:24 AM
- brown plugs tells me that there is something in the fuel that should not be. Did you use any kind of additive in your fuel? If you did, I assure you that is the problem.

No reason to change the FPR unless you plan to break the 400hp mark.

09-30-2013, 01:31 PM
I use only 98 or 100 octane fuel without any aditives.
The plugs are ngk bkr7e
walbro fuel pump, also tried with bosch pomp (the same)
The mapping is horsham stage 1
And it doe's not feel like 260-280 hp
I don't know what else can be wrong.

10-01-2013, 08:46 AM
I like to throw out odd stuff because if you search you can find all the common reasons to have this problem. So squeeze you intake and assuming it's stock it should have a spring inside of it so it doesn't collapse. Without that spring to keep it rigid the intake will sometimes collapse and choke out the car.
Sent from my HTC One using Tapatalk 2

10-01-2013, 12:24 PM
I'm sure that's the problem.

10-01-2013, 12:37 PM
He's in Romania, they probably use different additives there that turn the plugs a different color. Bromine used in Super Unleaded turns plugs red, it's not a big deal.
When you were told to check voltage, it wasn't alternator voltage, it was voltage AT the fuel pump. Check the wiring going into the fuel pump harness to make sure it's receiving 12+ volts and not 11.xx volts at idle.

10-01-2013, 12:43 PM
Check your coilpack harness. Also check your fuel pressure. Its possible the ecu went bad.

10-01-2013, 12:46 PM
I will check tomorow the voltage at the fuel pump.
I don't know how to check the fuel pressure but instead I will borow a ecu from a friend to see if anything changes.

10-01-2013, 01:09 PM
Did you re-gap the plugs? They are rarely ok out of the box.

Also please detail exactly how you determined that you do not have a boost leak. This sounds just like a boost leak to me - gas in exhaust, backfiring, no power, jerking back and forth.

Good luck!

10-01-2013, 01:46 PM
I did not re-gap the spark plugs.
The car used to work fine with them like this.
I'm not even sure how much sould be the gap between
For boost leak "I checked" by replacing all the hoses including the vacum lines and cover all the pipes with a mixture of water and soap.
Only thing that can be broken is the intercooler(I did not unmounted it to check it).

10-01-2013, 01:51 PM
Umm my response was completely serious. Just squeeze your intake and make sure there is a large spring inside of it...

10-01-2013, 07:40 PM
You need to pressurize your intake - block off the hot pipe after the turbo and rig something up to connect air compressor or bike tire hand pump to your intake. You need to see 15 psi on your boost gauge. If it can't get to 15 you have a leak. Listen for location and fix it.

What vacuum does your gauge read?

Boost leaks from silicone rubber pipe couplers can sometimes only open up at a threshold psi, like say 10 for example. Testing with any less pressure in the piping will not reveal this boost leak - but your car will stumble, buck back and forth and run really rich when you try to boost over 10psi.

For the plugs you said you have new ones, I have never had an NGK BRK plug come out of the box gapped down small enough for high boost. Compare them to your old ones.

Good luck!

10-01-2013, 10:41 PM
Boost on the gauge is 15psi and doe`s not decrease. On idle the boost is -19 psi.

10-02-2013, 02:36 AM
Check your knock sensor. Maybe it's retarding shit up. All rainman like.

Ninja edit...
I retread your posts and understand that you rubbed soapy water to test for boost leaks ??
That is bullshit. This ain't your moms corolla. You use/borrow/rent an air compressor build a $5 used boost leak tester and crank it.
If I misread your description and you actually pressurized the system to 15psi from the turbo intake on, then I apologize.

Did the PVC fail and your blowing boost out of the valve cover that you probably have a breather on the "T"

10-02-2013, 02:37 AM
On a side note. Maybe your Romanian blend switched from summer to winter.

10-02-2013, 09:22 AM
Boost on the gauge is 15psi and does not decrease. On idle the boost is -19 psi.

Well that sounds pretty good. Too bad it is not a boost leak because those are cheap to fix. :-/

10-02-2013, 10:52 PM
I know this is going to sound crazy, but I've run an SR20DET at 23psi and 15:1 air fuel ratio before. With 8* BTDC of ignition timing on 93 octane... It did not detonate. The major problem was heat. It got very very hot. The rings failed- on CP pistons after about 5 rounds of abuse and EGTS off the charts. But the engine had NO signs of detonation upon tear down.

In another example, somebody bought an S15 engine all OEM- and turned the boost to 18psi. It went lean AND it detonated, ruining the head and deck permanently. But I have to think that the cause was the ignition timing AND the lean air fuel ratio. Not just the air fuel ratio by itself.

After several rounds of trial and error I've come to the conclusion that the SR20DET only need the rich air fuel ratios to control heat. If your EGT is creeping up past 1350*F at wide open throttle... add more fuel to bring it down. the ignition timing is what is ruining the rod bearings, and head gaskets, and pistons/rings on these engines, not the air fuel ratio. The engine wont "knock" and it wont "detonate" or give you any clear indication that you have too much timing BTDC... it will just spit a ring/bearing/HG.

10-04-2013, 01:10 AM
So you didn't measure your spark plug gap? Proper gapping is important for SRs.. otherwise it will start blowing out if it's too large, which would result in something similar to your symptoms. As mentioned before, a lot of times the gap is off out of the box.

You won't know if you fixed your main problem if improper gapping is leading to additional issues. This is so basic that you should always check and fix before moving on. Even if it is not the issue, it's important to double check to rule it out as a cause.

Make sure the gap is no larger than 0.028".

10-08-2013, 02:57 PM
So during last days I checked the plugs. Adjust it to 0.028"
I also ordered a interface for diagnoze.
I have no errors.
Replaced almost all the hoses and all the metal brackets.
The car now is running better but still has some hessitation and doe's not feel like 260 bhp

10-08-2013, 03:45 PM
How is the 02 sensor? Post some pics of your setup so we can see what you're dealing with. Unbolt the fuel rail and kick on the fuel pump to check for oring leaks

10-09-2013, 12:28 AM
This a log from a few minutes running
I hope the link is working.

10-10-2013, 01:09 AM
So last night I made a few runs with the diagnose connected.
I think the problem is that above 3500-4000 rpm the charging goes down to 11.4 - 11.6
In idle the voltage is 13.7 - 13.9
And the spark is weak at high revs.
I will order a new alternator and keep you posted
Thank you