View Full Version : Tons of SR timing problems!!!

07-24-2005, 09:05 PM
at idle, when warm, my blacktop sits around 800 to 1000 rpm. it chooses between those two randomly (???). i tried adjusting my timing, by unplugging the TPS, reving the engine and then shooting the light. when i unplug the TPS my idle raises to 1500 and it won't settle down (reving the engine after unplugging didn't help either). i tried timing it at this new high idle, and trying to "mickey mouse" it until i could get the timing right when the TPS was plugged in. i got it to 15 deg advance with the first cylinder, but after going for a drive and experiencing all sorts of bogging and hesitation at 3000 rpm and 4500 rpm, i checked the timing again... for some reason the timing went to 5 deg advance! :hammer: i am totally lost. i can't seem to get my idle right, nor my timing. could the TPS be bad? or could a dead coil pack be the culprit here??

anyone know a more "overriding" method of timing? then again i should probably fix the high idle problem first..

any help would be sweet :rolleyes:

07-24-2005, 10:42 PM
car is also running super rich, with puffs of black smoke when reving.

07-24-2005, 10:50 PM
car is also running super rich, with puffs of black some when reving.

Sounds like a broken oxygen sensor to me. Unplug the o2 sensor and if the idle settles, you'll know it's broken.

07-25-2005, 09:27 AM
You have to have a steady idle to time your car. You also MUST have the tps unplugged when you time it. Your idle will always go down and your timing will always change when you plug your tps back in, this is normal.

DL the FSM and follow the timing/idle procedures EXACTLY. It is somewhat confusing but you just have to work through it.

The bogging, smoking, and hesitating when you drive is most likely due to your timing being too retarded.

07-25-2005, 09:43 AM
I timed my car with the tps plugged in. It stayed. My car wouldn't run with the tps unplugged for some reason it would just die.

07-25-2005, 11:12 AM
^^^ That does no meant the base timing is set right...only that you checked it 2 different times and the ECU was either 1) not fooling with it, or 2) holding the dynamic timing at 15btdc for some reason.

Your actual base timing could be 20, and the ECU can pull 5 degrees at idle...and it looks like you have the porper base timing.

You CANNOT set it properly without the TPS unplugged, AND the idle at ~700 (+/- 50rpm).

- Brian

07-25-2005, 11:03 PM
hey guys thanks for the responses,

i have a little update. today i removed all my spark plugs, regapped them to 30/1000 inch, and then cleaned them with carb cleaner. i then proceeded to do a compression test. cylinders 1, 2, 3, and 4 were 145, 143, 138, 135. this was with a cold engine and almost fuel flooded cylinders. this brings me to my next point.

i cleaned the IACV with some carb cleaner while it was still on the engine and the car was off. i then tried to start the car with no luck. when i took out the spark plugs they were soaked with gas, which leads me to believe that there might have been more gas than oil in my cylinders, another reason the compression might have been low.

anyway, to the problem at hand. after the IACV cleaning my idle smoothed out and stayed set. i unplugged the TPS and tried adjusting my idle by turning the screw on the IACV. i got it down to 800 rpms from 1500 rpms and then shut off the car and replugged the TPS. it also required me to screw the IACV screw all the way in.

i then checked the timing on the engine. it would sporadically fluctuate in between 13 and 17 deg advance. i couldn't keep it pegged on 15. the bogging during acceleration stayed the same so it leads me to believe that something else is messed up. i haven't checked the TPS voltage yet because i can't figure out how to do it. anyone know off hand the quick and easy way to test it?

i checked my injector impedence, and they were 11.5 ohms, clicking away ever so happily, so i know they are fine.

i am stumped. my only thoughts are that the ECU is fried (the housing had a dent in it when i got it), the KA SOHC MAF is dead or the TPS is a goner. then again it might be a coil pack. i really don't know.

help me out... i am running out of ideas... :ughd:

07-26-2005, 12:26 AM
Try using the carb cleaner on the Mass air meter

07-26-2005, 06:58 AM
did that allready... anything else?

07-26-2005, 05:48 PM
today i unplugged the MAF to see what difference it would make with it unplugged. as expected, i couldn't rev past 2500 rpm. with it plugged in can rev past 2500 rpm, but i still have the bogging and hesistation... anyone got any more helpful info for me? sometimes i feel like i am typing all this stuff for no reason.

07-26-2005, 08:40 PM
try a known good cas

07-26-2005, 10:48 PM
try unscrew the cover for the cam angle sensor......it happens to me that the degree wheel inside the cam angle sensor was twist......and damage the magnet pick-up...so everytime when i rev the car....it hesitate....and not letting me rev over 2000rpm....if the degree wheel is okie....check the voltage output from your [email protected] idle....usually is 0.8V to 1.2v

07-27-2005, 07:14 AM
how do i physically test the voltage out put of the MAF and the TPS? i know the connector still needs to be connected on both. so where do i get a reading from?

07-27-2005, 02:31 PM
Im having a similar sort of problem except mine only bogs down after i shift or completely let go of the gas and then try giving it gas and it stutters horribly and bogs. I t comes in stages but if i give it more gas itll work itself out. I changed the Plugs too. So thats wierd. If i figure out my problem ill let you know what I did to mine!

Theres an adjustment on the ECU I cant remember if its for a mixture or a idfferent kind of timing. Maybe that will help?

07-27-2005, 04:20 PM
anyway, to the problem at hand. after the IACV cleaning my idle smoothed out and stayed set. i unplugged the TPS and tried adjusting my idle by turning the screw on the IACV. i got it down to 800 rpms from 1500 rpms and then shut off the car and replugged the TPS... i then checked the timing on the engine. it would sporadically fluctuate in between 13 and 17 deg advance.

Follow the FSM directions and then come back. Pay attention to the words I highlighted because that seems to be one problem I'm seeing. One more thing, make sure you are using a cheap inductive timing light that doens't have fancy features. The fancy ones tend to read SR's 10 degrees off.

07-27-2005, 05:44 PM
umm ur a crack head...

i CHECKED not CHANGED the timing with the TPS plugged in. i think its time for u to read your own highlighted words, acknowledge the mistake and then hit the books. now, for someone that will actually have a helpful response: i checked the resistances on my TPS today and they are way off. i haven't figured out an easy non-intrusive way of checking the TPS voltages while it's plugged into the harness. someone please help me with this. i want to check the same for the MAF. should i take voltage readings at the ECU? i finally have my problem narrowed down...i think. i just need to double check it. also could a dead TPS cause my ECU to jump timing around, and not keep it set?

BTW: My coilpacks are all good too, i tested those 10 mins ago.

07-27-2005, 06:01 PM
Here you go dumbass. I'm going to hand this shit to you on a silver platter. You don't check or change your timing with the TPS plugged in. Maybe you should hit the books (FSM).

As for checking voltages, where the fuck do you think the best to check them is? The fucking ECU you retard. You can check them all day at the sensor by jamming the tip of your multimeter in there but it doesn't mean shit if your wiring is fucked. Here's a link for you cuz you can't seem to figure shit out on your own or listen to people that are trying to help you. http://www.datnet.org/new/techinfo/page1.html After you check the shit at the ECU, check the voltages at the sensors by jamming the thing in there. Confirm that your wiring isn't fucked up. Then make sure your sensors are all working properly.

Fuck, who knows if this is gonna help you out either.

07-27-2005, 06:40 PM
ok fuck face, a) your getting a little too excited here, b) your not helping me at all. everything you've said so far i allready knew before hand. oh i am so fucking honored to be fed with a silver platter, especially by you! unfortunately, the food is nothing new too me. i can tell your not capable of helping me. but i know there are others, that are tons more educated in the sr20det than both of us combined. i'd really like to hear from those individuals. people like you, Tardbert, try to nit-pick people's posts apart, just to feel a little better than another. or maybe you do it to easily add to your ever growing post count, huh tough guy? Moderator/Admin, its ur choice to kill this thread or keep it alive. eitherway it doesn't matter to me. thanks to those that were helpful.

Edit: The FSM and everyone i have talked to on Zilvia.net, have asked me to check the timing again once the TPS was plugged in.

07-27-2005, 07:03 PM
Reasons why your SR is gonna run like shit for the rest of the time that you own it.

1. You don't know how to check timing
2. You don't know how to check sensor voltages
3. You didn't read the FSM
4. You don't don't know how to listen
5. You call people crackheads that are trying to help and have waaaaaaaaaaay more experience with this shit than you do.

I am going to post a few more useful things for you that will help your dumbass. If you can't figure out how to fix your car from all the things I've posted, than you are better off taking your car to a more capable person like me and paying them tons of money to fix it.

1. Check your codes.

2. Quoting myself from another post:

"Check your timing. Go buy a cheap inductive timing light from sears or autozone or whatever. Make sure it's a cheap one that doesn't have any special features because the expensive ones like to read 10 degrees off on SR's. Warm up your car for about 5 minutes until it gets to operating temp. Turn the car off, unplug the TPS, turn it back on, race the engine a couple times, and check the timing with the timing light. Make sure it's set to 15 BTDC which is the second mark from the right.

If the timing is dead on, then you need to start checking your different sensors such as your MAFS, TPS, knock, ECT (engine coolant temperature) sensor. O2 sensor doesn't really need to be checked because it only operates when you are cruising with a steady constant throttle. Read the S14 SR FSM for specs on all the sensors. The only S13 sensor that has different voltage or resistance specs from the S14 is the MAFS."

3. If for some reason you just can't get your base timing done correctly by using the method above, you can set it manually by pulling your valve cover. Here is a link to the page in the FSM that shows you how to do it.

4. If this is a fresh swap, check your wiring and confirm it with the heavythrottle guide.

5. Change your oil soon because you are running really rich and you are diluting your oil with fuel, that is unless you feel like throwing a bearing.

07-27-2005, 07:52 PM
oh flybert!!

i knew i could get something slightly useful out of you. all it took was getting a little bit of your attention. now, in response to your accusations:

1. i know how to check and change timing. retard... my problem is that the timing oscillates between 13 and 17 deg advance, sometimes even further both ways. could the TPS have something to do with this?

2. i'll admit, i just figured the "testing sensors" thing out today. there must have been a "today" for you at one point in time as well.

3. i read the FSM 3 times a day, before work, lunch, and then before i goto bed. so suck it...

4. listening... don't hear much...

5. its funny how much offense you take to the term crackhead. maybe you really are one, and have come to realize that it may be a problem.

next set:

1. I don't think i am throwing any codes.

2. Timing is good, just fluctuating. and for some reason, just to spite you i feel like doing it my way (lol jk...dick)

3. might try this. but first i am gonna check the TPS, i really think that its the culprit.

4. Yuri from heavy throttle did the wiring. he said he would check out my car this week sometime. luckily, he lives in the next town over.

5. yeah.. i like fucked engines, don't we all?

this quarrel was slightly entertaining, at the most. i still hope you don't take it too seriously and go OD on some rock. anyway peace out brotha

07-27-2005, 08:17 PM
You don't need to check your CHECK ENGINE light to pull codes. In fact, I don't even think the CHECK ENGINE light works with SR's. In order to check your codes, you have to have access to your ECU. Pull off the kick panel on the passenger side. Next, turn your ignition to on but without starting the car. Now, your ECU LED light will light up. You then take a philips screw driver and turn the little knob in there to the right all the way. Let it sit for a second. Then turn it all the way back to the left. Now, the lights are gonna start flashing on you. Long flash stands for ten and short flashes stand for one. For instance LONG (10) LONG (10) LONG (10) LONG (10) LONG (10) SHORT (1) SHORT (1) SHORT (1) SHORT (1) SHORT (1) equals 10 +10 +10 +10 +10 + 1 + 1 +1 +1 + 1 = code 55 Now you need to look up the codes. I believe they have them on 240sx.org. The codes will tell you which sensor isn't working. If you get code 55, that means it's normal but it doesn't mean that your sensors are working properly.

As for the timing, does it fluctuate even when the TPS is unplugged? If I remember correctly, it's normal for it to fluctuate or to be off when the TPS is plugged. This is because your ECU is not in timing mode. I'd seriously consider doing the valve cover method that I posted above to get a base point while you troubleshoot your other sensors. Joe Rogan, I got something to tell you that you might not know. I smoke crack rocks.

07-27-2005, 10:01 PM
ok so i checked out my TPS some more. by using a multimeter at the ECU the input voltage to the TPS was 5.12V, the output voltage from the TPS to the ECU was .43V with the throttle plate closed, and at WOT it was 4.2V. these numbers seem good to me. so my TPS is good. what the hell else could be wrong? more and more i think the ECU is fried. also i noticed something really peculiar. my ecu doesn't have an LED, and the screw isn't flat head, its phillips head instead. i took the LED from my old KA ecu (same LED part number) and soldered it into the SR Blacktop ECU. there was allready an empty location for it. anyway, the LED didn't blink no matter what i did. how weird is that shit? :-/

flybert, stay with me a little longer...

07-27-2005, 11:44 PM
Dude, that fucking sucks about your ECU not having an LED. I've heard of a few people that didn't have one on theirs either. If you got your swap locally, ask for a different ECU with an LED in it or borrow a friends if possible. Philips head is normal for SR screw thingee. I'm really not sure what you are supposed to do to check codes if you don't have an LED. We can still check some other stuff.

OK, the TPS sounds alright but I gotta double check it. First thing first, You should bring your plug gap down to .028 (OEM spec). Also, go buy another set of some cheap ngk or denso spark plugs for now because the ones you are using are probably fouled and will make your car run like shit even if you do fix the problem. Next, you are gonna have to pull the valve cover and check your base ignition timing by the method I posted above. It should only take about 30 minutes if it's your first time. Just make sure not to fuck up the gasket when you reinstall it.

MAF voltage on s13 SR should be about .8V with key on and 1.8V at idle.
Check continuity of the knock sensor to the ECU. Just stab the prong into the plug of the knock sensor.

Also check continuity and the resistance of the engine coolant temp sensor. In order to check the proper resistances you are going to need a water temp gauge. If you don't have one, check the resistance when your motor is cold and when it's fully warmed up. You can verify these resistances in the FSM.

Also check the resistances of your injectors and coilpacks.

Last thing to check is the continuity of your IACV to the ECU.

Hopefully this will help you with everything you need to know. It's a time consuming process but when you get that POS running, you will feel good about the fact that you know about every aspect of the EFI system of nissan motors.

07-28-2005, 06:46 AM
yeah my ecu sucks ass! unfortunately i am rather new to the nissan scene so i don't have many 240sx friends. i got one ka-t friend but that doesn't help when it comes to parts. i used to be a toyota guy, when i still owned my mk3 supra turbo.

my injector impedence is 11.5 ohms. all four are the same, and they are all clicking. all four coilpacks are 1.2 - 1.3 ohms. so all that stuff is good. my plug gap is .030, which should be small enough right? i took out the plugs cleaned them with carb cleaner and they didn't look fouled to me. i think the problem lies somewhere else.

after work i am going to check the water temp sensor and the knock sensor. i am also going to try to manually set base timing like u suggested. so look for another update! thanks man, i'll take back what i said about u not being helpful.

07-28-2005, 12:22 PM
thanks man, i'll take back what i said about u not being helpful.

No prob. Don't forget to check the continuity of the IACV. I had a problem with my IACV that caused a similar problem that you are having. I had forgot to wire it when I threw my SR in and the car spit fuel out the exhaust, wouldn't rev over 4500, and it could make full boost with no load (just parking and giving it gas). It made it seem like a timing problem but it wasn't. I then fixed the problem but the car still wouldn't run right because my friend adjusted my spark plug bigger to try and help out. I think he set it to .034 so I brought it back down to .028 and it got everything running correctly. Seeing as your gap is .030 it shouldn't really be a prob, but it would probably be better to bring it to stock gap for now.

07-29-2005, 03:14 PM
my maf voltage is .8v with key on, and 1.8v at idle. my coolant temp sensor is within spec. so the tps, coilpacks, injectors, sparkplugs, maf, and engine coolant sensor are all out of the question. i believe the ignitor is good, but i don't know how to test a q45 ignitor. i couldn't find instructions anywhere.

engine coolant sensor continuity is good because when i unplugged it and then plugged it in again it changed the idle.

i still have to test:
IACV continuity
knock sensor continuity

anything else i am missing here before i accuse my ECU of being fried?

07-29-2005, 09:49 PM
one other thing. today when i inspected the IACV and the surrounding area i noticed that there is a 2 pin plug coming off the ignitor harness that was not plugged into anything. i am not sure if it has anything to do with the ignitor, but it is taped into the harness. Yuri from HT did the harness, but he never told me what this plug was for. the plug resembles the MAF plug because it also has a black boot on it, and its very rectangular and pretty small. it's also dark grey in color. thanks guys. where u at flybert???

07-29-2005, 11:26 PM
I've been drifting at the track all day. Buttonwillow Raceway is the best. Good times drifting in 100 degree weather.

Those plugs near your ignitor harness are not used in the swap. On the japanese car, they would plug into a stock boost control solenoid of some sort so don't worry about that.

One other thing I thought of is to check your injectors to see if they are leaking. Pull your fuel rail and check it for leaks. You do this by priming the fuel pump and check to see if the fuel is leaking by the o-rings or if they are stuck open. Prime the fuel pump by putting the key into the on position. Don't actually crank the engine or you'll spit fuel everywhere.

Make sure the silicone coupling on your intercooler piping isn't leaking because this causes big problems. Check the turbo outlet to make sure it's not leaking boost. Are your vacuum lines hooked up properly?

Check that IACV and pull the valve cover so you can set the CAS manually.

07-29-2005, 11:31 PM
What The Fuck. Button Willow Today!???

Shit! Tell Me Next Time!

07-29-2005, 11:34 PM
What The Fuck. Button Willow Today!???

Shit! Tell Me Next Time!

I thought everybody knew about it. It was posted here in the regional section and on ziptied. I'm hoping Al will throw another one there in like november. That would be sweet.

07-30-2005, 12:02 AM
Holy shit i'm on 2 forums at once and can't control myself.

I wasn't paying attention to the events stuff.. my fault...
Man i don't have skills but I DO HAVE TIRES!

Oh well.

07-30-2005, 09:46 AM
yeah i know i got no fuel leaks. i am still thinking i might have a boost leak. supposedly you can pinch the PCV blow by hose and if the idle rises then u know u have a leak. i am gonna try that right now.

08-02-2005, 09:53 PM
another update, this is where it gets interesting.

today i set my base timing by taking off the valve cover. i know i did it correctly but my timing still jumps around and won't stay steady. it jumps from -5 to +5 degrees.

i also swapped out my spark plugs with some new ones gapped at .030. that didn't do anything. i also replaced my ECU and coil packs with working ones. didn't change anything either.

i am thinking that it might be my q45 ignitor. how would i go about testing this POS ignitor. anyone have a link to a q45 fsm, that is applicable to my ignitor. i have the ignitor that needs rewiring, not the drop in kind.

please let me know.

08-02-2005, 10:04 PM
when you do timing tdo you have to JUMP something??

08-03-2005, 07:50 AM
umm what are u talking about? i never said i had to jump something to do the timing. i said my timing JUMPS around and won't stay steady!

i really need to know how to test a q45 ignitor.

zenki s14
11-09-2005, 03:08 PM
sorry to bump an old thread back up. But I also got the same problem. Im also having a weak spark in cylinder one. I swaped out the ignitor and no difference. BTW did you ever got the timing right?

clutch kick drifter
12-14-2005, 01:20 PM
Hey i have a blacktop in my hatch and im having the same problem. How did you test your coilpacks? Mine does it after 4500 rpms after the engine warms up completly ( usually 15 min). My timing is steady at the second mark though.
Also if i had a boost leak wouldent my boost gauge read low vacum? It reads about -20 which is normal.

12-14-2005, 04:07 PM
it turned out that i had a bit of dried up salt in my cas due to shipping overseas. open it up and check it out. u test the coil packs by swapping them out with someone elses good working set.

12-14-2005, 06:14 PM
my newly done blacktop swap is timed properly (tps off, idle adjusted, warmed up) and is rock steady with the tps off. Plug the TPS in and the car tries to find an idle and stumbles then stalls. Driving, the power is very random and trying to maintain a speed it bucks stumbles and pops. doesnt even try to idle. Sparkplugs are at .032. For some reason I thought stock was .036?? will go down to .030 tomorrow but ive got CRAZY healthy spark across all 4 cylinders anyway with new NGK Iridium's. My MAF is an unknown entity... got it off some 2 pump chump on ebay for $40. Revs fine tho. No rich mix black smoke so my O2 is probly ok. Didnt install my Walbro yet but i will this week. CAS looks beautiful inside and is properly installed after finding tdc.