Some of you may remember reading my earlier thread. I just finished putting a 99 short block and intake manifold into my 2002 car.
VVT Head
99 Short Block
99 Intake manifold
99 Fuel Rail (could this be a problem?)
VVT oil pump
Reverant MS3

Tunerstudio says "VVT1 Err" and the car loses sync while it cranks.

I'm using the same tune that I had before. I figured since I kept the VVT head, very minimal changes were needed. Perhaps the lower short block compression, different intake manifold, and different fuel rail would change things so much that the car wont start?

At first I put the crankshaft timing plate on backwards but I swapped it around and still no luck. The crank sensor was also a bit far away from the nubs and now I have it very close. I'm not sure how much closer I can get it. The car cranks but doesn't even try to start. I have spark (at least cylinder 1 does because my timing light worked, but the car ran fine before the swap) and I'm pretty sure I have fuel since the plugs were wet when I pulled them.

This was my first time swapping an engine and also first time doing a timing belt. When I tore down the car again to reverse the timing plate, I re-checked the timing belt and everything seems to line up. The intake cam looks slightly out of position though, but could this be because of VVT? I'll attach a picture.

I'll also attach a log and my tune. The tune was largely done by the owner of the car before me so be easy on me. Battery voltage is a bit down, but the car still would not start even when being jumped. If needed I can take another log with the car being jumped if the RPM need to be higher.

Any help is much appreciated,
Sean

 

I would figure out what got changed in the MSQ to cause the VVT1 Err. It sort of sounds like you have 2 things set to that output. Could disable VVT in TS real fast and then try starting and see what it does.

 

Nothing was changed as far as I can tell. I even tried using a MSQ from last year and same problem. I just disabled VVT and tried it and it still loses sync, although obviously the VVT error no longer appears. No change in behavior of cranking.

I may have used some sensors from the 99 engine in my car. But everything hooks up to my 2002 wiring harness just fine so I don't think it could be that unless some sensors are different internally. Ones I can think of are the EGR, maybe the crank position, and that little plug that attaches to the wiring harness but doesn't seem to be a sensor on the back of the driver's side of the head.

Could the crank position sensor be bad?

 

It is not EGR or the sensor on the back of the head that goes nowhere. Go to the Diagnostics & High Speed Loggers in TunerStudio. Then do a composite log and post in here. It sounds like either the CAM or Crank sensor is bad or going bad. A few quick things to check would be that the 4 toothed timing wheel is on the correct direction, then crank sensor clearance. I use a CC to set the clearance between crank sensor and a tooth. Then you could try swapping out the cam/crank sensors with other known ones.

 

I've tried to do a composite log but for some reason they're not saving. I'll try to figure it out.

I just did a cold compression test. Got 180 across the board except for cylinder 3. It tested at 100psi. Checked again, still 100 psi. Dropped some oil in:180.

Would this stop the motor from starting? And I swear if this short block has bad compression I'm going to throw a fit. I picked it up from a well known Miata performance shop and they listed the compression at about 180 across the board.

 

You need to click the "Capture to log file" button before you start the test to get it to save the log file.

I don't think the compression being low on cylinder 3 would cause the car not to start.

 

This is what I got. It wont let me open it up in Tuner Studio for some reason but I can open it with Excel.

 

Your MS is synching after a while. it takes it a full 2 revolutions, but you are getting synch.
However, it looks like your cam timing may be off. Here's a composite log from my (running) '99:



And here is the log from your engine:


My cam marks come in right in the middle between two marks on the crank. Yours are offset. Could be the VVT- I'm not familiar with that. But of course if your cam is off a couple of teeth, your engine wouldn't start.

 

I appreciate your advice. Hopefully it is just the VVT. I've checked the timing twice and as far as I can tell it is correct. The pictures I included in my original post show the cam sprockets aligned with cylinder 1 at TDC.

 

So I got the car to start by giving it part throttle and cranking, but it sounds like a leaf blower and dies as soon as I let off the gas.

So my timing is messed up? Is it possible that I need to set the timing offset on the Megasquirt by using a timing light while cranking to get it to run correctly?

If not, how the hell do I time the engine correctly? Yesterday I posted pictures of my timing belt, sprockets, crank, and cams to Miata.net and they all said the timing looked fine.

Is it possible that the VVT actuator was installed on the cam wrong somehow? I had a shop clean up the head. Maybe they messed it up?

I leave the country in two days and I need to get this car to move before I leave.

 

Post the pictures of your timing here.

 

Timing photos here. Crank was at TDC

 

Did you confirm the crank was at TDC by using a dowel to make sure the piston was actually at TDC

 

I made sure it was at TDC when I put the head on. The crank remained at TDC until the timing belt was on according to the arrow on the block.

 

Unless it is the camera angle, it looks as though both the cam gears are not pointing correctly and your timing marks on the bottom pulley are off.

The notch on each cam gear should be lined up visually with the ridge by the "E" and "I" on the plate.

 

To me this smells more like a VVT actuator problem than a timing belt alignment problem. Are you sure it's got a good oil feed? Did you take it apart? Are you sure it's working after whatever incident prompted the replacement of the short block?

--Ian

 

I've seen something like this before where the intake cam pulley was installed improperly, the alignment dowel smushed into the cam and the cam pulley was "off" despite everything looking alright with regard to alignment marks. Similar MS failure to sync as well, though I don't think I have those logs anymore.

 

Take off the lower timing belt cover. Measure TDC based on the mark on the block and the dip thing on the pulley. From looking at the pictures you posted I think both the intake and exhaust cams are off. It could be the angle of the pictures on the exhaust cam, but on the intake cam the lobes are definitely a bit higher then they should be.

 

I really don't think the cam gear marks are off. The exhaust cam seems to be dead on, but it's almost like the intake cam pulley is misaligned with the cam.

So I'm trying to remove the intake cam gear and VVT actuator. I got the bolt out and the gear moves a little but won't come off. Do I just have to pry harder? And yes, I know theres a Million little pieces inside the VVT actuator.

This is the backside of the intake gear. It looks lined up to me?

 

Sorry for the double post, but here's what I'm seeing.

Here are pictures of both cams at the timing marks, which I also have a picture of.

In the cam picture, I've made marks indicating the angle of the cam lobes. As far as I know, when the cam gears are at the TDC timing marks, these lobes should face at the same angle towards eachother. Obviously the intake cam is too far clockwise.

In the sprocket picture, I've shown the gears lined up with the timing marks. I've accounted for the angle of the camera with the red lines, showing that if you looked at the gears from directly in front they would line up with the marks exactly. The angle of the camera just makes it look off.