whitesileighty

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

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

Bump, forum slow in the middle of the day?

dorkjoey240

check ur maf n plugs.

whitesileighty

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

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

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

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

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....

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whitesileighty

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

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

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....

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ESone3

try a new MAF, they go bad more often then not

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whitesileighty

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

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

Yes, limp mode kicks in with the MAF disconnected. It should idle.

greenman100

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

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

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

Does it ever fire? I mean, when you're cranking, do you ever hear it change in pitch?

whitesileighty

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

I doubt it's MAF. I'd say it's ECU, CAS, or wiring.

Have you pulled the codes on the ECU?

whitesileighty

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

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

im thinking timing. take pics of your cam gears with the top of the head perfectly level (on tdc of course).

whitesileighty

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.

aNskY

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

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

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

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.

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