Resolved Cam swap with H8 ECU and 1g CAS in a 95 GS-T.

[kiddsm95]

I recently installed some BC 264/264 cams along with a 1g CAS so that I can run my 98 flashable ECU. Lined up the the cam marks even with the head and the dowel pins at 12 o'clock, oil pump sprocket, balance shaft sprocket and crank sprocket were lined up as well. Reinstalled everything and turned the crank pulley to ensure everything rotated smoothly.

For the 1g CAS I followed the magnus and RRE write-up, which were straight forward. I soldered the 4 wires and followed the diagram to a tee. Now my car won't start! I tried inverting the 6 pins on the ECU plug and running the factory 95 ECU and the car wouldn't start, swapped the pins back and tried running the H8 ECU, still won't start.

Here's what I've checked:
1. 1g CAS with key to on position ensured that injectors and fuel pump relay actuates.
2. Tried another 1g CAS, still won't start.
3. Checked fuel system, plenty of fuel.
4. Checked for blown fuses.

Anyone have any ideas as to what is going on?

I did sever the OEM 95 crank sensor power wires (blk & red) from the plug when wiring in the 1g CAS. I'm pretty sure I don't need these since the 1g CAS provides both the crank/cam signals.

Before all this work the car ran great, with no issues.

Any help is appreciated.

 

[Sam@RRE]

Take the CAS off of the head. Leave the harness connected to it. Take all the spark plug wires out of the cylinders and let it rest on the valve cover. Turn key to on, and rotate the CAS trigger by hand. You should get a crazy taser show. If not, check your CAS wiring. It shouldn't really matter, but you are supposed to use the power and ground wires from the 2g crank sensor connector, and connect to the red/black on the 1G cas. White wire from 1G CAS connects to 2G cam angle sensor blue wire. And Yellow wire from 1G CAS connect to 2G Crank sensor blue wire.

 

[brassc2007]

it doesnt need a first gen ecu to do that do ya?

 

[kiddsm95]

I forgot to mention that I completely removed the OEM 2g cam sensor from underneath the intake cam gear, because when I installed the cams the sensor under the cam gear got crushed when I put the gear back on.

When I check for spark using a spare plug there's plenty of spark, and when I pull the fuel return line on the driver side of the fuel rail fuel squirts everywhere.

What's the point of the taser show? Just to ensure the wiring of the 1g CAS is correct?

 

[Ceddy]

it doesnt need a first gen ecu to do that do ya?

The 1G, 97-99, and Evo CAS are basically the same signal wise. Only the 95-96 have the funky inverted cam signal.

OP, you most likely have a wiring issue.

Try swapping the plug wires, 1&4 with 2&3.
And check the CAS isn't 180* off.
If none of that works, check wiring.

What's the point of the taser show?

That will show that you are getting a CAS signal to the ecu, and the ecu is giving you spark. If you are getting spark, something is out of phase, plug wires or CAS.

 

[chrisb33]

OT: are those bc cams older models? i dont think bc makes 264's anymore. just asking coz i want to get bc 264's but all they have are 272's.

thanks.

chris b

 

[kiddsm95]

OP, you most likely have a wiring issue.

Try swapping the plug wires, 1&4 with 2&3.
And check the CAS isn't 180* off.
If none of that works, check wiring.


That will show that you are getting a CAS signal to the ecu, and the ecu is giving you spark. If you are getting spark, something is out of phase, plug wires or CAS.

I've tried starting the car on both the H8 & 95 ECU with the CAS "on" as well as 180° off.

I followed Sam's advice lastnight and there was no "taser show". When you say leave the plugs on the VC, do you mean with the spark plugs still in the block, or with the spark plugs in the plug wires on top of the VC? I used some spare plugs and had them connected to the plug wires and there was some spark, but by no means would I catagorize it as a "tazer show".

As for the plug wires, I thought that swapping 1&4 with 2&3 wasn't required when utilizing an H8 ECU and 1g CAS? Regardless I tried this and when cranking the car it would rotate the engine 2-3 times then make a high pitched crank. By high pitched I mean the same kind of sound you get if you were to swap the cam/crank signal wires from the CAS (ie swapping the white/yellow wires on the CAS to the opposing blue wires on the square and rectangular connectors).

~ chrisb33: Sorry, these are Crower camshafts. http://www.extremepsi.com/store/customer/product.php?productid=18946&cat=255&page=1&veh=2G DSM

Silly question concerning the wiring connections. Does it make a difference if the 1g CAS wires are attached on the ECU side of the electrical connectors vs the sensor side of the electrical connectors? I basically cut the OEM cas and crank wires off of the connectors, then wired in the 1g cas to reuse the existing connectors. Plugged everything back in and now I have a no start/no taser show issue.

 

[brassc2007]

Re-read Sam@rre's post about the wiring you need to connect the right ones cause right now it is getting no crank singnal cause it is not wired in properly i would try as sam said

 

[Sam@RRE]

CAS inversion is mainly for the injectors. You can have the injector fire at the wrong time, but the car will still start and run. If you get the spark to fire at the wrong time, it wont. And when you swapped the plug wires, the original coil that used to go to 2&3 now go to 1&4. The other coil that used to go to 1&4 now go to 2&3. Simple as that.

The point of the taser show was to see if your wiring is working properly. If you get spark you are getting a crank signal. Put a stethoscope on the injector (or long screwdriver in your ear works) and check to see if they are clicking. If not, check for switched power on one side of the injector connector, if you have switched power, then the ECU is not grounding the injector due to lack of cam angle signal. If it is not, then you have a problem with wiring to the resistor box on the firewall.

 

[kiddsm95]

CAS inversion is mainly for the injectors. You can have the injector fire at the wrong time, but the car will still start and run. If you get the spark to fire at the wrong time, it wont. And when you swapped the plug wires, the original coil that used to go to 2&3 now go to 1&4. The other coil that used to go to 1&4 now go to 2&3. Simple as that.

The point of the taser show was to see if your wiring is working properly. If you get spark you are getting a crank signal. Put a stethoscope on the injector (or long screwdriver in your ear works) and check to see if they are clicking. If not, check for switched power on one side of the injector connector, if you have switched power, then the ECU is not grounding the injector due to lack of cam angle signal. If it is not, then you have a problem with wiring to the resistor box on the firewall.

I can hear the injectors clicking when I rotate the CAS by hand. If the ECU is not grounding due to a lack of cam angle sensor does that mean my 1g CAS is bad? What can cause the resistor box to go bad? Can swapping plug wires in many different configs cause this? Please keep in mind that the car ran perfectly before the cam work.

I'll look into that resistor box wiring.

 

[the_mork]

You got the plugs and injectors to fire so you do have CAS signal, cross that off your list.

Next you need to check only a few things. You have fuel, and you have spark so there are only two things left that a motor needs in order to run properly and those are compression, and the be in phase.

Basically if you have compression it is a phase problem, and we'll assume you do because it ran before and everything that you've changed that would cause you to not have compression can be considered a phase problem

Start with the easy stuff by figuring out and making sure that you are getting your spark events at the right time. Basically from the original stock position of your 7bolt motor you should have swapped the spark plug wires from one coil to the other. DSMs use a wasted spark system so it only matters that each wire is on the correct coil pack and not what order they are in otherwise. If that works then the car should probably run just fine at cruise and idle even if your injectors are out of phase but they shouldn't be if you have the CAS correct so that is where we go next. Try the CAS how you have it then flip it 180*. If none of that works then I suggest that you have a compression problem because of your cam install, you could be off by a couple of teeth or you could have failed to bleed the lifters/installed the cams out of phase enough that you've smashed your valves against the pistons. We'll hope that that isn't the case though and you probably would have noticed.

I would actually suspect that you didn't get the cam gears lined up properly when you put your timing belt back on. Double check your work before you try to crank it over again, if it isn't far off your valves should be fine.

I did sever the OEM 95 crank sensor power wires (blk & red) from the plug when wiring in the 1g CAS. I'm pretty sure I don't need these since the 1g CAS provides both the crank/cam signals.

Was this in a writeup? I think I would have left them alone unless the instructions specifically mentioned cutting them.

This part is unfortunately something I don't have a lot of experience with but it sounds fishy to me. Hopefully someone who has done a few swaps can clarify.

 

[kiddsm95]

If none of that works then I suggest that you have a compression problem because of your cam install, you could be off by a couple of teeth or you could have failed to bleed the lifters/installed the cams out of phase enough that you've smashed your valves against the pistons. We'll hope that that isn't the case though and you probably would have noticed.

I would actually suspect that you didn't get the cam gears lined up properly when you put your timing belt back on. Double check your work before you try to crank it over again, if it isn't far off your valves should be fine.

Was this in a writeup? I think I would have left them alone unless the instructions specifically mentioned cutting them.

The lifters sat for 1-2 days after installing the new cams because I've been taking my time with this mod. I've read that they really only need about 3 hours to fully bleed, so we should be good there.

Timing is lined up everywhere, and the engine rotates smoothly. 3 years ago when I purchased the car I changed the timing belt and had the timing off by 1 tooth, the car still started but it ran a little rough. Is it possible to bend valves when turning a motor with a 12" long 1/2 rachet? When I turned the motor by hand it didn't require much force. 10 lbs on the end of the ratchet possibly, so 120 in-lbs of force... I'll run a compression check tonight just to make sure.

The reason I cut the 2g CAS off was because the plastic body of the sensor drooped when I pulled the intake cam gear. Since it was drooped the body of the sensor sat much lower at the end (think deflection distance), so when I installed the cam gear the sensor got crushed. I ended up cutting it off since the 1g CAS needed to be wired in anyways.

As for being in phase, I also tried starting the car with the 95 ECU connected and swapped pins 1, 2, 14, & 15 on the ECU connector per the RRE write-up. I also swapped pins 10 & 23 to invert the signal at the igniter so that I wouldn't have to swap plug wires. Shouldn't that have technically brought the 1g CAS into phase to work with the 95 ECU? The car still wouldn't start in this configuration.

 

[the_mork]

Lifters need to be bled using a small nail or pin, you stick it into the end and you can press on a release valve the pump the lifters a couple time to get excess oil out.

Sounds like your fine there though with a free spinning motor so no, I don't expect bent valves. Potentially a motor that is very close in tolerance (off a degree or two or with a shaved head) might be okay when just spinning the motor but could damage valves at high RPM due to valve float but that isn't your case and I'm just mentioning it because it is tangentially related.

 

[kiddsm95]

What about swapping plug wires 1 & 4, then 2 & 3? Is this the same thing as swapping ECU connector pins 10 & 23? If so, then being out of phase can be ruled out correct?

What about the resistor box as Sam mentioned? Also, how probable is it that the coil is bad? If the coil is bad wouldn't that result in no spark at all?

 

[jrohner]

You have to swap the plug wires if you're going to run it on a 95-96 ECU, but you leave them alone for a 97+ ECU. If they're wrong, you'll know, as you will get a bunch of popping when trying to start it.

 

[kiddsm95]

Ok, lastnight I tore everything back apart and the timing was good. My father-in-law is an experienced mechanic and he insisted in re-installing a brand new 2ga cam sensor (even though I didn't want one, but whatever), so we put a new sensor under the intake cam gear and reset the timing points. Timing points were perfect everywhere again, motor turned freely. Still not starting.

Swapped plug wires as suggested and still not starting.

Things I still need to check:
1. Compression.
2. Resistor box - How do I check this? Plenty of spark, does this need to be checked?
3. Crank sensor signal.
4. Coil.

What's the possibility that the engine is flooded with gas? How do I clear out the combustion chamber?

 

[romeen]

What's the possibility that the engine is flooded with gas? How do I clear out the combustion chamber?

I doubt that's the case but pull the spark plugs, shine a light down through the plug hole and look. If there is gas sitting on top of the piston then you could:

1) Get creative on a way to suction it out

2) If the motor is turning over then you could pull the main engine ("MOTOR") fuse in the engine bay then crank it with all the plugs removed. It will get a bit messy but the gas would simply be spit out through the plug holes. You may want to double check that fuse anyway now that I think about it.

 

[Sam@RRE]

If it's getting fuel and spark, the motor fuse is good (ECU turns on), CAS wiring is good, you don't use your crank sensor anymore (1G CAS puts out the signal for both). It's a phasing problem. Set the motor to TDC, set the CAS at TDC. Make sure you set the CAS at about center on the adjustment.

Also, make sure your coolant temp sensor/MAF/TPS () is hooked up (you'll get spark and fuel with it disconnected, just not the right amount of fuel)

 

[kiddsm95]

Compression is good and the differential between cylinders is less than 10 psi.

Since I installed a new sensor under the cam gear I measured the resistance on the crank sensor and there was nothing. So I replaced the crank sensor with a brand new unit. Also replaced the temp sensor just in case mine was faulty. It's still not starting.

Speaking of the MAF. On our cars when you unplug the MAF connector shouldn't the ECU sense this and throw a CEL? I can unplug the MAF connector and the crank sensor, even the CAS and the ECU doesn't throw one code. Is there a possibility that my ECU fried? My father-in-law brought a scan tool and there are no DTC's being provided. In the past I would get the usual O2 sensor CEL and I would have to clear the DTC's, so I would imagine that something like a crank sensor failing would generate a lot of DTC's. In fact why didn't my ECU sense that the crank sensor was bad in the first place?

How likely is it that wiring up the 1g CAS incorrectly can fry an ECU?

Could it be the MPI relay?
Yay, 100 posts.

 

[Sam@RRE]

Wait....
why are you even using a crank sensor anymore?
THE 1G CAS REPLACES BOTH THE CAM AND CRANK SIGNALS. Read on electrical involved in a 6bolt swap. If you are installing your 1G cas, you will not be using your stock crank and cam sensors anymore.

 

[kiddsm95]

Because I'm just trying to get the thing back to normal, so I said to hell with the 1g CAS. Once I get this sorted out I may try the 1g CAS again, but this time I'll have a dedicated harness for it instead of cutting into my good sensors.

As for the no start issue, I think it's the MPI relay.

 

[Sam@RRE]

if you are getting fuel and spark, then your MPI relay works. All it does it turn on the fuel pump and ECU.

 

[kiddsm95]

if you are getting fuel and spark, then your MPI relay works. All it does it turn on the fuel pump and ECU.

Since I can unplug the cam, crank, airflow sensor and the ECU doesn't throw a single code does that mean the ECU is fried? I was thinking it was the MPI relay, so the ECU isn't getting booted.

 

[kiddsm95]

Any other ideas why my dsm won't start? where is the resistor you mentioned above, and how do I test it?

 

[Sam@RRE]

you mentioned that you are getting fuel and spark. So resistor pack is good, and cam and crank sensor is working. It is a phasing problem