View Full Version : rebuilt SR won't run?!?!
whitesileighty
03-26-2009, 08:27 AM
I rebuilt my sr20det after it leaned out and I melted a valve. After the rebuild I went with 86.5mm CP pistons, eagle rods, replaced all the gaskets, 740cc injectors, z32MAFs, greddy intake manifold, enthalpy ECU, 264/264 BC cams, cometic headgasket, arp head studs.
Sounded simple enough but I put everything together and I am trying to crank it over and it won't fire. I triple checked the timing on the motor and it's right, I'd put $1000 on the table that the CAS and the timing chain are exactly right. When it cranks over it has fuel, spark, and compression. Though sometimes it seems the spark doesn't go off. I.E. when I pull one of the coilpacks and put the plug into it then ground it on the head it will fire 3 out of 4 times or so. Seems really random.
I'm thinking if it were a grounding issue I wouldn't be able to get the car to turn over. Anyhow my theory is the either 1) there's a ground issue or 2) there's something wrong with the harness and I need to tear it apart and look at every wire to see if there's an issue.
Thoughts?
whitesileighty
03-26-2009, 11:01 AM
Is it possibly a timing issue related to the BC cams? I talked to a BC rep and they said that everything was setup for stock timing, but I remember reading something on the forums about the BC cams needing adjustment from stock timing on the forums somewhere.
I just want to be able to start the damned thing.
whitesileighty
03-26-2009, 02:37 PM
Bump, forum slow in the middle of the day?
dorkjoey240
03-26-2009, 02:50 PM
check ur maf n plugs.
whitesileighty
03-26-2009, 11:52 PM
Just to cover previous issues in case it helps. When the valve went down originally the car was still drivable on 3 cylinders. I obviously wasn't driving it since it wasn't fun and I didn't know what the problem was so I didn't want to cause more dmg than was already done. But I bought a house and attempted to drive on 3 cylinders to the new house and got 1/2 way there before it gave up the ghost and had to be towed the rest of the way.
When I send the ECU to Enthalpy Scott said the thing was fried and was amazed the car was running on it. The power ins on the board were actually burnt up (literally burned). I pulled the harness and looked it over and nothing is blatently apparent and the new ECU hasn't fried with me trying to start it up. I assumed that the ECU was probably bad and caused me to lean out and melt the valve originally. But now that it seems to be acting somewhat the same as when it stopped running with almost everything replaced.
I'm looking for guesses as to what people could guess on for me to check. I'm at a loss and don't care to pay someone by the hour to troubleshoot the problem, because no mechanic is going to do this for free. But if I can't get some new ideas I'm going to be forced to take it somewhere and have someone charge me $1000 as they attempt to re-time and redo all the work I've done 10 times until they start guessing at the strange possibilties.
greenman100
03-26-2009, 11:57 PM
If you have timing, fuel, spark, and compression, it will run. it's that simple - you're missing one.
are you certain you set your CAS to TDC on COMPRESSION STROKE?
whitesileighty
03-27-2009, 08:21 AM
Yeah, that's what I thought too. I rebuilt the thing myself I.E. only took the head and block to machine shops for machine work and assembled everything myself. I'm familiar with the concepts of a motor and specifically the assembly of this one. When I turn it over it tries to fire and then seems to skip before it actually catches.
I'm thinking I will check the coilpack harness and make sure none of the wires are stripped or crossed under the shielding and maybe I'm sending too many sparks and it's why I can't get consistant spark. Maybe the ignitor chip on it's way out.
Again I said that the spark isn't constant. It only fires 75% of the time or so. And as I was testing it, it seemed that it was firing more often on #1 than on #4 coil. I swaped the #4 coil to the #1 location and it was the same. So there's nothing wrong with the coils. I think it's either got to be a wiring issue or the ignitor is on the way out. Not sure if this is a possiblity. For the most part I've heard that the ignitor either works, or doesn't. Can they partially go out? I can't say I'm as familiar with how the ignitor chip works.
greenman100
03-27-2009, 01:33 PM
are you certain you set your CAS to TDC on COMPRESSION STROKE? How did you verify this?
ignitor chips can partially fail, yes. FSM troubleshooting procedure is not reliable.
slider2828
03-27-2009, 01:40 PM
Replace with known good ecu, but you have everything tuned to it... Is the ECU known good? Also, shorting the MAFS, shorting the Injectors, Shorting the alternator = fried ecu for sure.... You better check these grounds....
whitesileighty
03-27-2009, 01:49 PM
Sadly I borrowed a buddy's ignitor chip and I have the same issue. Unfortunately I don't know anyone with 740cc injectors and z32 MAF or I would check against a known good one. I was thinking that Scott (Enthalpy) would let me know if the ECU was busted when he tuned it. I'll double check the grounds to see if that gets me anywhere.
whitesileighty
03-27-2009, 01:52 PM
Oh and to make sure it was at TDC I used the shop manual and verified with the 2nd timing mark on the crank pulley, 10 o'clock and 12 o'clock for the pins on the cams. When I got paranoid that I screwed it up I found something that Enthalpy posted on his site and started counting chains and making sure everything lined up. And it's exactly right on how many chain links etc.
slider2828
03-27-2009, 02:37 PM
well if you rebuilt your whole motor, you have to make sure the bottom link matches to the crank pulley oh wellz.... But really sounds like ecu or grounds....
ESone3
03-27-2009, 02:51 PM
try a new MAF, they go bad more often then not
whitesileighty
03-27-2009, 03:32 PM
I have tried starting it without the MAF connected. Doesn't "limp mode" kick in if the MAF is disconnected? Limits me to staying under 2500rpms but it should at least start right?
whitesileighty
03-27-2009, 03:35 PM
and yes, I timed it right the first time when I first put it all together. Since then I have checked the timing at least 4 times and it's still right. I'm thinking we've got a shot with the ECU, cause I'm REALLY confused. If I got an ECU set for 550cc injectors instead of 740s like I requested that would just flood the motor out wouldn't it? Or would it still run just really rich?
greenman100
03-27-2009, 06:30 PM
I have tried starting it without the MAF connected. Doesn't "limp mode" kick in if the MAF is disconnected? Limits me to staying under 2500rpms but it should at least start right?
Yes, limp mode kicks in with the MAF disconnected. It should idle.
greenman100
03-27-2009, 06:32 PM
Oh and to make sure it was at TDC I used the shop manual and verified with the 2nd timing mark on the crank pulley, 10 o'clock and 12 o'clock for the pins on the cams. When I got paranoid that I screwed it up I found something that Enthalpy posted on his site and started counting chains and making sure everything lined up. And it's exactly right on how many chain links etc.
you need to be at TDC on your compression stroke - the mark on the pully just indicates that it's set to TDC, on either your exhaust OR compression stroke.
when you install the CAS< ensure the cam lobes on the #1 cylinder are facing outwards. this means it's on compression.
i'm only harping on this because i was in you shoes a few months ago, and went insane. it ended up that i was setting it on exhaust, completely by chance, several times in a row.
MELLO*SOS
03-27-2009, 06:42 PM
you need to be at TDC on your compression stroke - the mark on the pully just indicates that it's set to TDC, on either your exhaust OR compression stroke.
when you install the CAS< ensure the cam lobes on the #1 cylinder are facing outwards. this means it's on compression.
i'm only harping on this because i was in you shoes a few months ago, and went insane. it ended up that i was setting it on exhaust, completely by chance, several times in a row.
I'm with this guy.. I've done this same thing before by accident (CAS/Timed on TDC Exhaust stroke) and the symptoms are exactly as you say. You sound like you know what you're doing but maybe it's something simple you overlooked.
If you have spark and fuel then I'd focus on timing for a little bit until something else obvious comes along... You have good fuel pressure & plugs are wet after cranking for a bit? Fuel pump relay is good, pump is good, lines are hooked up correctly, regulator set correctly? Just throwing stuff out there, good luck dude must be frustrating bet you can't wait to drive it again!!
whitesileighty
03-27-2009, 07:19 PM
Yeah, the intake came lobe is pointing towards the intake side and the exhaust cam is pointed toward the exhaust. Everything in cylinder 1 is closed.
I'm literally so close to just buying another redtop to have spare parts to test every sensor, plug, and harness. There's a good deal on a running one here in town ($3000 S13 with redtop running perfect). I might just buy it so I can test another harness and then I can swap out to the stock injectors/ECU/MAF if need be to be able to figure out if it's the ECU that's killing me.
Unfortunately I think I'm at a point that I'm unable to do much of anything else without having parts to swap out, and that's going to add up in the $1000s by the time I order every freakin sensor possible and take months to slowly order them all so I'm not stuck with 12 things I didn't need.
Strangely my wife gave me the OK to buy a 3rd 240 to have something to test against. So that would make 1 90 S13 hatch with redtop, 1 93 vert, and another 93 hatch with redtop. Once I figure out this whole pain in the arse I'm selling this stupid bad luck chassis and I'll swap everything into the vert.
Anyone else with ideas out of the ordinary. I'm down with concepts of the wiring harness getting squished and crossing wires, coolant sensor (if you could explain how it could create the problem), basically anything anyone else can think of before I go spend 3k on a car to use as a troubleshooting device.
greenman100
03-27-2009, 07:23 PM
Does it ever fire? I mean, when you're cranking, do you ever hear it change in pitch?
whitesileighty
03-28-2009, 09:33 AM
Yeah, it seems to randomly catch and the motor shakes, but it doesn't ever catch and fire all the way. The spark plugs have blackened fuel on them but are still wet. I wish I had another ECU to test with. I'd be able to figure out if it's the ECU then. I still have the old injectors and the MAF is wired with the old plug still for troubleshooting, so I could put the old MAF on and test.
greenman100
03-28-2009, 10:51 AM
I doubt it's MAF. I'd say it's ECU, CAS, or wiring.
Have you pulled the codes on the ECU?
whitesileighty
03-28-2009, 11:27 AM
AHA! I've found a new symptom/problem. I went out to continue playing with it this morning and found unburnt fuel in the IACV hose. I upgraded to a Greddy intake manifold during the process and the instructions on that I found far more confusing than timing the motor.
I'm thinking I might have screwed something up with the intake manifold install. I'll be pulling that tomorrow and see what I find. But basically there was literally like 6 or 7ozs of blackened fuel in the tube. So either my injectors and just dumping fuel to the point that it's coming out both sides, or there is something totally wrong happening here.
I'll pull the intake manifold and see what I come up with. Worst case I'll switch back to the stock manifold.
whitesileighty
03-29-2009, 10:35 AM
False alarm, it's not continually getting fuel in there. I was just from when I didn't de-pressure the fuel line and pulled the injectors. So I'm still in the dark.
aNskY
03-29-2009, 11:24 AM
im thinking timing. take pics of your cam gears with the top of the head perfectly level (on tdc of course).
whitesileighty
03-29-2009, 01:08 PM
Kinda pointless to try and take the pic of the cams level with the RAS installed, they block the entire pic. But it shows the the lobes on 1 are both pointing outward, to the best of my knowledge that's the correct timing down to the link. And every 2 rotations it lines up the same, so the chain isn't off by a link or anything wrong (didn't feel like rotating for 10mins to get the colored links to line up for the pics. I'd love for someone to prove me wrong so I can start my car though. So if someone thinks it's still off please explain how and what's wrong in the following pics.
http://i42.photobucket.com/albums/e348/sileighty12/P1010001.jpg
http://i42.photobucket.com/albums/e348/sileighty12/P1010002-4.jpg
http://i42.photobucket.com/albums/e348/sileighty12/P1010003-3.jpg
http://i42.photobucket.com/albums/e348/sileighty12/P1010004-1.jpg
http://i42.photobucket.com/albums/e348/sileighty12/P1010005.jpg
aNskY
03-29-2009, 04:38 PM
i meant just the front of the gears, so we could count the links.... but it looks good from those pics...
time to borrow / buy more parts lol
whitesileighty
03-29-2009, 06:06 PM
Alright, if we go back to the symptoms before the rebuild. When it stopped running, I'm guessing that it's the same problem. I drove it on 3 cylinders to the gas station and when I shut it down, it never started again after. Would it be possible that the IACV died and I just can't idle and thus I can't start the car because the throttle body is closed?
greenman100
03-30-2009, 12:54 AM
sure, it's possible, but I doubt it. crack the throttle with the gas pedal while cranking.
your timing looks good.
what's your compression?
SoguRacing
03-30-2009, 01:23 AM
perhaps there's a short in the coil pack harness. do a compression test to make sure everything is sealing properly...valves, seals, rings... numbers should be 150psi across the board...maybe a bit lower since you have BC 264 cams as overlap is more prevalent at lower rpms. after that's verified, make sure that the fuel injectors are firing. take out the rail..not the injectors and place a cup under each and have a friend turn the key and see if they are all spraying and spraying properly..please wear safety glasses during that process haha. after that is done POST again.
aNskY
03-30-2009, 06:54 AM
is your coilpack harness grounded to the back of the head?
Sileighty_85
03-30-2009, 09:04 AM
Do Cel codes still work on the Enthalpy Tuned ECU's?
Sounds like the CAS is bad, try swapping it with a known good one
greenman100
03-30-2009, 09:13 AM
Do Cel codes still work on the Enthalpy Tuned ECU's?
Sounds like the CAS is bad, try swapping it with a known good one
they do for me.
whitesileighty
03-30-2009, 09:39 AM
I haven't checked compression yet, but with the BC springs on the valves it's a real bitch to turn over with a wrench without removing the spark plugs, so I know it's got compression. I'll run the test on it tonight, I've got no doubt that it's got compression though, and plenty of it.
I tried opening the throttle a little bit while starting it and it didn't start, so I guess that rules out the IACV. And when I tested the ignitor from a friend I also borrowed his coilpack harness, so both of those have been ruled out. I'll post compression after I test tonight.
godsmack
03-30-2009, 09:47 AM
Besides for the obvious did you happen to clean you're plugs after the first initial start up? When i swapped my motor out i had the same problem happen to me and i cleaned my plugs and it fired right up. Might not be ur problem but just something to shoot for if you haven't already tried it.
whitesileighty
03-30-2009, 10:03 AM
They were brand new plugs originally, and I keep cleaning them every time I pull them out. They're covered in blackened fuel when I pull them out.
godsmack
03-30-2009, 10:20 AM
When you swapped out the ignitor and harness did you check to see if you had the same firing symptoms? You're spark isn't keeping up with the fuel. swap in stock injectors see if it will fire with less fuel.
whitesileighty
03-30-2009, 11:09 AM
Tried that too. No go. I swapped the battery and am now getting constant spark when I test, so it's just problem after problem. Currently constant spark plenty of fuel, doesn't come any closer to starting when the stock 370cc injectors are in that when the 740cc injectors are in.
whitesileighty
03-30-2009, 12:11 PM
Oh and yes, the coilpack harness is ground to the back side of the head. It was a pain in the arse to remove the ground to test the second coilpack harness because of the bolt location. I not only tested the coilpack harness by installing it and testing, I also used a multimeter and figured out there were no issues with it.
whitesileighty
03-30-2009, 02:05 PM
Let me phrase another way to see if I can get some more ideas. Assuming a car is running name the sensors that would prevent it from starting again once you shut it off. TPS, MAFS, IACV (if it completely died), CAS? Any others? Cause I'm thinking coolant sensor, oil pressure, O2, knock, and any others shouldn't keep it from starting, maybe from running well, but it should still start.
I haven't looked at the TPS so maybe I'll see if I can figure out how to test it to be able to see if that's causing the issue since I've ruled out the other 3.
godsmack
03-30-2009, 03:54 PM
well tps could be it since you're getting fuel and spark. so now it has to be an air problem. so i guess take off the intake mani and tb clean everything up just take off upper mani though. and also clean the iacv up real good.
godsmack
03-30-2009, 03:55 PM
and cas would also not let it start but usually that deals with the spark side i'm pretty sure.
greenman100
03-30-2009, 06:02 PM
I haven't checked compression yet, but with the BC springs on the valves it's a real bitch to turn over with a wrench without removing the spark plugs, so I know it's got compression. I'll run the test on it tonight, I've got no doubt that it's got compression though, and plenty of it.
I tried opening the throttle a little bit while starting it and it didn't start, so I guess that rules out the IACV. And when I tested the ignitor from a friend I also borrowed his coilpack harness, so both of those have been ruled out. I'll post compression after I test tonight.
Check your compression.
whitesileighty
03-30-2009, 08:53 PM
alrighty... pulled the fuel rail and pressurized it without it being mounted, placed plastic bags over the ends of the injectors. Then turned the motor over, each injector was shooting fuel so everything is good there.
I have no idea what compression should be on a brand new rebuild before the rings have had a chance to seat (it's not started once since rebuild). Then the BC 264/264 cams have overlap so that drops the compression numbers some more. Then I have the 1.01mm headgasket too so down the number goes a little more. But I'm 110psi across the board. I'm doubtful that it should be higher seeing as the rings haven't had a chance to seat and the above info. I poured a little oil in #1 and tested again to get a better seal and I'm at 130psi
Almost forgot to mention I live in Denver, so at this altitude I'll never get 150psi. The air is too thin for sea level compression.
The ECU is throwing the 55 code (nothing wrong). I tested all the sensors with a multimeter and everything seems right except the O2 sensor, and I don't know what it should be, but voltage seemed really low compared to the other sensors. But the CAS, TPS, MAFS, and coolant sensors are all in the ranges they should be. And an O2 sensor shouldn't keep it from starting.
yokotavia
03-30-2009, 09:53 PM
replace your coil pack harness and maybe your coil packs.
your not getting spark.
your not getting spark.
your not getting spark.
well at least the right amount of spark..
your saying its not starting and your plugs are soaked with unburnt fuel. thats a coilpack/spark issue
borrow those from a friend and test it.
its not compression.
its not the ecu
its not timing if your as right as you think
check out the sparkplug/ignitor/coilpack/coilpack harness/coilpack ground
fliprayzin240sx
03-31-2009, 06:35 AM
Stab in the dark...but is your fuel line in properly? As in you didnt crossed them? Check that (best way to remember it, line from the fuel filter NOT to the regular), then id say check the compression to make sure it wasnt the rebuild.
whitesileighty
03-31-2009, 07:08 AM
its not timing if your as right as you think
Heh, I did post pics and no one else has told me I'm off there either.
check out the sparkplug/ignitor/coilpack/coilpack harness/coilpack ground
Already tested the plugs/ignitor/coilpack harness/coilpack ground. I guess I'll borrow someone's coilpacks, but I am pretty sure this is a larger issue. Once I replaced the battery, I have constant spark now.
Stab in the dark...but is your fuel line in properly? As in you didnt crossed them? Check that (best way to remember it, line from the fuel filter NOT to the regular), then id say check the compression to make sure it wasnt the rebuild.
Yes, fuel lines are correct.
greenman100
03-31-2009, 06:54 PM
basically all that's left is the ECU, CAS, and wiring in between.
slamed_s13
04-26-2009, 11:32 PM
Any progress? Did you ever figure out the problem whitesileighty (http://zilvia.net/f/members/whitesileighty.html)?
whitesileighty
11-10-2010, 11:06 PM
I had to look up this post because a friend wanted to know my pre-starting compression numbers for troubleshooting his car.
Just to update the problem was that the exhaust cam snapped in 3 pieces before it ever started. Apparently it was damaged in shipping or something. When I installed I was staring at the shop manual torquing everything to spec in order so I know I didn't screw it up. Once I threw stock cams in it started right up.
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