SR20det ignition timing issues/engine getting hot

[doridoridori]

I have a Redtop SR (S13 SR20det)
it was refreshed a year ago (new rod/main bearings, new rings, stock bore,etc.) and before I ran it everyday no issues.
around the end of last year I had a metal headgasket installed/tomei cams, but that's it nothing else changed. I bled the coolant (upper/lower rad hoses get warm) so im sure my thermostat didn't just go bad sitting. For some reason the engine has been getting hot (200-210F). once it gets to 210F i just park it, let it cool down and eventually got back home.

Im assuming my ignition timing is a little off which might be the cause of it, I double/triple checked the CAS and it's spot on and when I go to put it in "timing mode" (let the car warm up 170F, pull the TPS connector, rev it 3 times around 3k rmps) the timing marks are bouncing quite a bit. I tried the sequence multiple times tonight and could never get it where it needed to be. Is there anything else im missing?? is getting it to set in that timing mode that inconsistent? im not sure what to do at this point but any help would be greatly appreciated!

[nmerriw]

Are you shutting the car off before pulling the TPS? I found that I had to unplug with the engine off, and then make sure idle was below 1k to get consistent timing readings.

I also had very similar temp issues due to a tiny leak below my intake manifold, by the time the car was getting hot the coolant was below that level so it wasn't immediately obvious.

[doridoridori]

Originally Posted by nmerriw

Are you shutting the car off before pulling the TPS? I found that I had to unplug with the engine off, and then make sure idle was below 1k to get consistent timing readings.

I also had very similar temp issues due to a tiny leak below my intake manifold, by the time the car was getting hot the coolant was below that level so it wasn't immediately obvious.

no im not, at least on all of the videos ive seen they pull the tps as the engine reaches op. temps, but i can give that a try and see if anything changes.

also all my gaskets are new-ish only got about 8k miles on the engine.

[dorkidori_s13]

what are you running for engine management? if you installed aftermarket cams and didnt retune, thats probably your issue.

also are you running an FMIC? clutch fan or electric fan? what front bumper do you have? what oil are you running?

[nmerriw]

Originally Posted by doridoridori

no im not, at least on all of the videos ive seen they pull the tps as the engine reaches op. temps, but i can give that a try and see if anything changes.

also all my gaskets are new-ish only got about 8k miles on the engine.

I'd double check that all the hoses under the manifold are good, there are a lot in that area

[doridoridori]

Originally Posted by dorkidori_s13

what are you running for engine management? if you installed aftermarket cams and didnt retune, thats probably your issue.

also are you running an FMIC? clutch fan or electric fan? what front bumper do you have? what oil are you running?

entalpy tune and they are tomei poncams i'd imagine they shouldn't need a retune but i could be wrong.

yes running a FMIC, electric fan and rotella 5w40 (been using that stuff forever)

[doridoridori]

Originally Posted by nmerriw

I'd double check that all the hoses under the manifold are good, there are a lot in that area

I'll double check but i had the engine out and replaced everything when it was out so im doubting that's possible but i'll look again

[doridoridori]

Originally Posted by dorkidori_s13

what are you running for engine management? if you installed aftermarket cams and didnt retune, thats probably your issue.

also are you running an FMIC? clutch fan or electric fan? what front bumper do you have? what oil are you running?

ended up sending the ecu off so should get it back maybe end of next week, i'll update just so this info can be helpful to someone else

[dorkidori_s13]

Originally Posted by doridoridori

ended up sending the ecu off so should get it back maybe end of next week, i'll update just so this info can be helpful to someone else

this is most likely your problem. when you change cams, youre changing behavior in the cylinder. the fuel cools the cylinder chamber. when you change the overlap and duration of the cam, you need to change how much fuel is being injected into the cylinder itself. most likely the issue right now is that youre running lean.

honestly, ROM tunes are a very outdated way of tuning motors. a full stand alone would be the best route to go. ROM tunes were a 90s and early 00s way of tuning a motor. in modern times, standalones have come leaps and bounds beyond ROM tunes. even running an old school stand alone like a PowerFC is well beyond anything a ROM tune can do.

[jedi03]

210 isnt that hot...thats pretty normal operating temperature...

[dorkidori_s13]

Originally Posted by jedi03

210 isnt that hot...thats pretty normal operating temperature...

SRs tend to be fairly cool running motors when tuned properly. with factory ECU, NISMO thermostat, Koyo Radiator, GK Tech clutch fan and OE fan shroud, my SR rarely saw temps above 190-195 in middle of summer during daily driving. NOT during Sept-May is generally in 165-175 range at most. even on stock thermostat, i never saw over 200 deg during middle of summer.

my current setup will SOMETIMES eek passed 200 with PowerFC DJetro and tune (with same hardware mentioned above) during heat waves.

if youre pushing into the 210-220 range, then it has to do with the tune on the motor during normal driving. 220-240 didnt become normal operating temp range until late 90s/early 00s in a lot of motors. 210-220s in an SR during normal operation warrants attention... especially if running clutch fan + shroud.

[doridoridori]

Originally Posted by dorkidori_s13

this is most likely your problem. when you change cams, youre changing behavior in the cylinder. the fuel cools the cylinder chamber. when you change the overlap and duration of the cam, you need to change how much fuel is being injected into the cylinder itself. most likely the issue right now is that youre running lean.

honestly, ROM tunes are a very outdated way of tuning motors. a full stand alone would be the best route to go. ROM tunes were a 90s and early 00s way of tuning a motor. in modern times, standalones have come leaps and bounds beyond ROM tunes. even running an old school stand alone like a PowerFC is well beyond anything a ROM tune can do.

yea that makes sense, i should've thought about that before hand, was doing a lot of work to the car aside from the cams and once i got everything buttoned up, started to test drive it to work out any bugs (this being one that presented itself). Also my aem sensor went bad so that was another thing, replaced it as soon as i noticed it. I definitely don't disagree rom tunes are outdated but i had no issues with my entalpy tune. I daily'd, drifted every event and drove the car home and to work 5 days a week on the rom tune lol. Not saying I wouldn't consider a standalone at some point but my setup isn't too crazy that the entalpy tune can't handle.

[doridoridori]

Originally Posted by jedi03

210 isnt that hot...thats pretty normal operating temperature...

is that right? well usually my car stayed around 170-180F max when cruising around, and at events (in the summer) it would creep to 205F max. With it getting hot and i wasn't even getting into boost that caught my attention and made me want to park it.

[doridoridori]

Originally Posted by dorkidori_s13

SRs tend to be fairly cool running motors when tuned properly. with factory ECU, NISMO thermostat, Koyo Radiator, GK Tech clutch fan and OE fan shroud, my SR rarely saw temps above 190-195 in middle of summer during daily driving. NOT during Sept-May is generally in 165-175 range at most. even on stock thermostat, i never saw over 200 deg during middle of summer.

my current setup will SOMETIMES eek passed 200 with PowerFC DJetro and tune (with same hardware mentioned above) during heat waves.

if youre pushing into the 210-220 range, then it has to do with the tune on the motor during normal driving. 220-240 didnt become normal operating temp range until late 90s/early 00s in a lot of motors. 210-220s in an SR during normal operation warrants attention... especially if running clutch fan + shroud.

that makes sense, yea i had a feeling something was up tune wise once i couldn't get the timing set properly. even if 200-210 isn't the worse I wasn't going to try and push it, it never "overheated" and i definitely wasn't getting into boost at those temps so we'll see how things change once i get the ecu back. Im running a nismo thermostat (170F), redline water wetter & distilled water. No clutch fan/shroud but it isn't a Schassis so there's no room for one.

[jedi03]

well guess i need to go back an check how my last sr is running...all of mine ran hot ~200-220 regardless of fan setup...dont know where your numbers came from with the "old" temps, been working on cars since early 90s and doin vehicles as far back as 1930 restorations...all the thermostats, unless low temp/racing were opening at 180...

[Kingtal0n]

1. Never run any engine long with water cooler than roughly 185*F
... because it accelerates engine wear everywhere not just the cylinder

2. Temperature reading MUST be confirmed:
A. use at least two different temp sensors
B. try to use two different locations on the engine (ex. 1 in head, 1 in the water outlet to rad)
C. Pay attention to where the temp sensor location is with respect to water temp,
i.e. water WARMS as it moves from one side of the engine to the other,
most engine have TWO different temp sensor locations (e.g. LS engine head location choice) and this will impact the reading!
-most engines flow from back to front- so take your reading near the front


3. The ideal temperature range for majority of daily drivers with turbochargers is near 190 to 195*F (195 to 200*F outlet temps). For "old" engines like sr20det a max of roughly 210*F is recommended when using gasoline and especially when climate temp ambient is 80*F ( hot outside like Florida)

However!
210 to 225*F is technically "safe" for engine oil and engine coolant temps.
It isn't good when using gasoline because the high temp upsets the fuel and that is NOT GOOD when using turbochargers to boost compression.

-> Also there is temp rise as the engine accelerates, so if the engine starting at 210*F then it will finish the run at 220 or 230*F is likely.


Thus, we should keep our turbo sr20det engines near 190*F perhaps 188*F as much as possible, then allow them to warm to near 210*F as they are heavily loaded / raced around.

Note / example
* an outlet temp of 195 to 200*F could put the temp inside the engine near ~182*F at some point

[Kingtal0n]

Now to the issue of timing

The rom-tuned ecu isn't going to impact cooling temps
there is very little if any difference in tuning for any sr20det with respect to ignition timing and camshaft changes, for most changes this is true.

That is because the engine uses a cruise timing which is similar no matter what the compression ratio of a turbo engine can encompass.

In other words, a typical turbo engine is already using a very low static compression ratio (8.5:1 or 9:1 is typical) therefore while cruising the alterations to engine VE due to camshaft and other mods is negligible with respect to gasoline ignition timing tuning.

So, there is nothing in your ECU causing your temp related issues unless it was some kind of mistake or bad part involved, or bad wiring I guess (its not tuning related).

If anything, as camshaft "size" increases, engine VE increases, which would call for LESS ignition timing at wide open throttle (MORE EGT = less timing)

---

Now the timing itself, could be an issue. most timing light have a directional pickup. The critical issue with sr20det timing is the position of the CAS. Take a careful look at where it is positioned between the lockdown bolts. It should be just slightly off-set (the bolt is not quite centered in the slot).
Next, check the timing, then FLIP the pickup on the coil pack wires. In other words, flip the clamp around 180* so the wire goes from left to right instead of right to left (or whatever). Then re-check the timing.

The timing which yields 15* BTDC while the cas is nearly centered (bolt in the center of the slot adjustment) is the correct timing. When flipped incorrectly it should push the CAS off to one side (FULLY moved to the edge of the slot).

[doridoridori]

Originally Posted by Kingtal0n

Now to the issue of timing

The rom-tuned ecu isn't going to impact cooling temps
there is very little if any difference in tuning for any sr20det with respect to ignition timing and camshaft changes, for most changes this is true.

That is because the engine uses a cruise timing which is similar no matter what the compression ratio of a turbo engine can encompass.

In other words, a typical turbo engine is already using a very low static compression ratio (8.5:1 or 9:1 is typical) therefore while cruising the alterations to engine VE due to camshaft and other mods is negligible with respect to gasoline ignition timing tuning.

So, there is nothing in your ECU causing your temp related issues unless it was some kind of mistake or bad part involved, or bad wiring I guess (its not tuning related).

If anything, as camshaft "size" increases, engine VE increases, which would call for LESS ignition timing at wide open throttle (MORE EGT = less timing)

---

Now the timing itself, could be an issue. most timing light have a directional pickup. The critical issue with sr20det timing is the position of the CAS. Take a careful look at where it is positioned between the lockdown bolts. It should be just slightly off-set (the bolt is not quite centered in the slot).
Next, check the timing, then FLIP the pickup on the coil pack wires. In other words, flip the clamp around 180* so the wire goes from left to right instead of right to left (or whatever). Then re-check the timing.

The timing which yields 15* BTDC while the cas is nearly centered (bolt in the center of the slot adjustment) is the correct timing. When flipped incorrectly it should push the CAS off to one side (FULLY moved to the edge of the slot).

Interesting well either way my ecu was already sent off so when i get it back (hopefully by saturday or early next week) i'll see if anything changes. Do you have any photos of how you mean the timing pickup should be?

[Kingtal0n]

Yep took me a minute to find but here is the post where I show, read the whole thing maybe

https://zilvia.net/f/showpost.php?p=6373984&postcount=9

picture:


Recap:
Once you read the timing one way, flip the pickup around 180* so its facing the other direction and check again.
Most pickup (the thing that clamps onto the wire) have a little arrow showing the direction of the spark towards the plug, but don't rely on that; just check the timing both ways and then you need some common sense/knowledge of which way is correct
1. The cas will be nearly center when the pickup is flipped properly (slight offset)
2. The engine will seem to run well, normal even
3. The timing will be steady as long as the TPS is disconnected. It doesn't matter when you disc the TPS, running or not running.
4. Rev the engine and check the spread, it should advance timing to say 25 or 30* or something like that (from 15 original).
5. Always set to 15* btdc timing unless you are advanced tuning expert.

[doridoridori]

Originally Posted by Kingtal0n

Yep took me a minute to find but here is the post where I show, read the whole thing maybe

https://zilvia.net/f/showpost.php?p=6373984&postcount=9

picture:


Recap:
Once you read the timing one way, flip the pickup around 180* so its facing the other direction and check again.
Most pickup (the thing that clamps onto the wire) have a little arrow showing the direction of the spark towards the plug, but don't rely on that; just check the timing both ways and then you need some common sense/knowledge of which way is correct
1. The cas will be nearly center when the pickup is flipped properly (slight offset)
2. The engine will seem to run well, normal even
3. The timing will be steady as long as the TPS is disconnected. It doesn't matter when you disc the TPS, running or not running.
4. Rev the engine and check the spread, it should advance timing to say 25 or 30* or something like that (from 15 original).
5. Always set to 15* btdc timing unless you are advanced tuning expert.

sweet much appreciate the info, that is definitely something I didn't think about before, I figured once the clamp is around the wires it should read regardless but i'll make a note of that and try both ways because what seemed to be close to 15deg the CAS was all the way to one side and that didn't seem right to me. Also I did speak to a few other ppl after installing cams and they also told me they needed retunes after so we'll see, either way the ECU should be back come monday so i'll report back with info

[Kingtal0n]

The engine needs tuning even if you don't install cams;

The cam part isn't what necessitates the tuning part- the engine has a MAF sensor which means it can compensate for additional mass of airflow when the cams are installed easily. It also uses an O2 sensor for cruise/idle to adjust for inconsistencies in the MAF caused by changes to the head/cam/etc...

So, on one hand, the cam upgrade should be handled by the maf and O2 sensors. There is no need to "tune" anything because the maf and O2 adjust a/f ratio based on their measured values.

On the other hand, the OEM tune is not ideal, or even intended for our climate or gasoline in some cases. The OEM tuning for sr20/2jz tends to use too much ignition timing and a slightly leaner a/f ratio than we desire.
Furthermore, the aging of the MAF sensor and inconsistency of the user-end plumbing (the style of intercooling and type of plumbing components) adds variability to how the maf is going to interact, as a perfectly positioned maf sensor is rare.

Next, the maf itself is a question as the OEM maf can only supply maybe 300rwhp? Or so. After that you would need a Z32 maf (something larger) which obviously requires a re-tuning as well. And of course, larger injectors to support the increased power.

Thus, it isn't the cam install that facilitates the re-tune. It is really these:
1. the necessity of removing the OEM Maf sensor and adding Z32 sensor
2. adjustment for the age and position of the different maf sensor
3. tuning for larger injectors
4. "fixing" the oem timing and fuel maps

To put this into perspective, If you bring me an OEM sr20det engine with all factory maf/injectors/ecu/turbo/etc....
I could easily replace the maf, injectors, ecu, and perform a re-tune that would work well with the OEM turbo and engine.

Then, you can take the car and drive it for 5 years or whatever, then do a mild cam and turbo upgrade and it would not require any re-tuning because I've already fitted the new maf and injectors to work with the engine at any Mass-airflow-rate (up to approx 500hp).

[Kingtal0n]

Originally Posted by doridoridori

but i'll make a note of that and try both ways because what seemed to be close to 15deg the CAS was all the way to one side and that didn't seem right to me.

This is the problem you had the timing at like 30* btdc or something crazy when the cas is set like that. You had the pickup reversed. Easy fix

[doridoridori]

Originally Posted by Kingtal0n

This is the problem you had the timing at like 30* btdc or something crazy when the cas is set like that. You had the pickup reversed. Easy fix

ok so ecu got back in today, i plugged it up and warmed the car back up. First thing i noticed was at idle it wasn't running as lean as it was previously and idle'd a lot smoother. I warmed the car/engine up and went through the "timing procedure" again (get it to operating temps, removed the tps, rev it past 3k three times) and that should be timing mode. Also after getting the ecu back i noticed the timing marks weren't jumping around as bad as before BUT the CAS sits pretty close to one side (the right ear is close to touching the bolt to lock it down) but it doesn't sit close to the middle. If i turn it the other way it's nowhere near the 15deg mark on the crank pulley.

my other question is and i've heard doing the timing sequence doesn't always lock for some reason. So what can remedy that? and i have had a cas off a tooth before but it would not run, it revs smooth no hiccups or hesitation/misfires at all and before I sent the ecu off i made sure to re stab the cas to verify it was spot on where it should be.

p.s. - i flipped the timing pickup both ways and it didn't change a thing.

[Kingtal0n]

1. I recommend a compression test, take all plugs out, spin the motor with a battery charger to help, write it down

2. CAS off to the side is a warning flag. I've never seen an engine do that or need that. Sounds like you need to try another timing light or a different procedure (try using a plug wire instead of the coilpack wires) or maybe the cam isn't installed correctly? What size cam and does it run rough?

3. Timing should stop jumping around once you unplug the TPS. If it does not, could be a poor wiring of the tps sensor causing noise in the tps signal. Or an issue with idle speed, does the idle change because of an air leak maybe?

4. Pressure test the plumbing after the compression test

5. Are you using the correct mark? On the damper iirc it goes -5 0 5 10 15 20


Summary
Compression and pressure test, check tps wiring, use a different timing light

The ultimate test is, does the car drive normal, have good compression and make the correct power. If you think its good to go it will drive normal and then take it to a dynojet and put down the right amount of juice and /done

[doridoridori]

Originally Posted by Kingtal0n

1. I recommend a compression test, take all plugs out, spin the motor with a battery charger to help, write it down

2. CAS off to the side is a warning flag. I've never seen an engine do that or need that. Sounds like you need to try another timing light or a different procedure (try using a plug wire instead of the coilpack wires) or maybe the cam isn't installed correctly? What size cam and does it run rough?

3. Timing should stop jumping around once you unplug the TPS. If it does not, could be a poor wiring of the tps sensor causing noise in the tps signal. Or an issue with idle speed, does the idle change because of an air leak maybe?

4. Pressure test the plumbing after the compression test

5. Are you using the correct mark? On the damper iirc it goes -5 0 5 10 15 20


Summary
Compression and pressure test, check tps wiring, use a different timing light

The ultimate test is, does the car drive normal, have good compression and make the correct power. If you think its good to go it will drive normal and then take it to a dynojet and put down the right amount of juice and /done

compression is fine it's got about 8k-9k miles on it since it was rebuilt and it actually drives fine as it sits with the cas the way it is. Doesn't hesitate/hiccup or nothing. Maybe rpms are a bit too high (tac doesn't work though) which is why im trying to find a 14pin consult port to get an accurate reading of where everything is.

TPS wiring is fine (just installed a brand new wiring specialties harness a month ago so wires are new).

and on the timing light i borrowed a friends light (snap on light with a dial) but I went ahead and bought one from autozone so that's 2 lights already.

on the cams it's tomei poncams (the drop in ones 258 Int/exh.) the dials are on the marks no issues there.

and on the mark yes im using the right one (the second one from right to left 15*deg mark).

I will say before i drove the car every day no issues and the CAS was sitting as it sits now almost maxed to one side, however i've always heard people say it should be centered or close to so im wondering if some cas' sit a little different (i'd imagine it shouldn't but maybe it does??)

[doridoridori]

[IMG][/IMG]

not my pic but it looks like that when it reads 15deg.

[Kingtal0n]

factory position

If it moved from here,
1. cam maybe not installed properly (tooth off?)
2. wrong timing
3. ECU maybe programmed differently than OEM for timing base mark
4. ?? Engine/head decked too far? Would that do it

[doridoridori]

Originally Posted by Kingtal0n

factory position

If it moved from here,
1. cam maybe not installed properly (tooth off?)
2. wrong timing
3. ECU maybe programmed differently than OEM for timing base mark
4. ?? Engine/head decked too far? Would that do it

1. Im going to pull the valve cover and check again after work and triple check.

2. wrong timing as in mechanical timing ??

3. it's entalpy tuned so highly doubt that is incorect he has it set at 15deg.

4. nah it wasn't decked crazy or anything like that.

[Kingtal0n]

Set the lobes facing outwards. Count the 20 links between the dots. The cam lobes both face out and about 2 or 3 degrees, very little bit upwards. So they wont be perfectly flat or 180* across, each lobe facing out will also face a tiny bit upwards.

[doridoridori]

Originally Posted by Kingtal0n

Set the lobes facing outwards. Count the 20 links between the dots. The cam lobes both face out and about 2 or 3 degrees, very little bit upwards. So they wont be perfectly flat or 180* across, each lobe facing out will also face a tiny bit upwards.

my bad meant to reply earlier (been busy with work).
I finally got a consult port/adaptor in the mail so going to try it out to see, I wonder if my idle may be too high to set the timing properly (tach doesn't work) it doesn't seem to idle too high but it could be a little off since i have no way to read it.

Also another thing I was thinking about is obviously all the CAS from SR's are interchangable, I wonder if lets say for example a S14 or S15 CAS on a S13 SR changes it's position maybe? just a thought but never heard anyone talk about that before.