Madcar

Hello, thanks for taking a look at this. I am sure that some of these issues are covered in other posts so pls forgive me if they I'm duplicating...

My problem is, recently I went through 16 NGK 10.5 plugs, that cost!

The car is damn hard to start, especially on the hotter running plugs, I am currently back on some BR9T's as at least the car will start with 8 or 10 tries, once going it ticks over really sweet, no burbles or any funny stuff.

I checked the compression and I get 60psi on all faces of both rotors, I get this cold/hot/throttle open or closed.

Now I checked the timing a few days ago, took out the CAS and set the first mark on the front pulley to TDC, lined up the notch on the cas shaft with the dimple on the CAS gear, marked the gear inside, put the CAS into the motor and adjusted the CAS back to line up the pickup.

The car seemed ok until today (it was a pig to start but at least it went) BUT today it started detonating, this occurs anywhere above idle, little bit of throttle or a lot! more so under heavy load obviously.

So, I have changed out the fuel today for some higher octane stuff, nope. I retarded the CAS as far as it would allow without taking it out, this didn’t help.

As a note, the pulley closest to the block also has notches on it, look to be about 30 degrees behind the marks on the front pulley. I timed up on the front pulley.

So I have a race in the morning and I have no car any help you guys/girls could offer would be really appreciated.

Sorry this is so long…

Here's my baby @ Time 3.47: http://www.youtube.com/watch?v=vDOD1...eature=related

Tvm

beefhole

iTrader: (29)

Your engine is dead. Of course it's hard to start. Everything else... well yeah.

Madcar

Thanks, I only rebuilt it about 8 months ago using Atkins parts.

Do you really think it's dead?

beefhole

iTrader: (29)

That compression is terrible. Was it hard to start 8 months ago after the rebuild? What was the compression then? 60/60/60 on both rotors is a sign of dead motor.

Some other info. On a hotter plug, you should be starting much easier. Cold plugs would make it tougher to start. The higher the number, the colder the plug. If you are using 10.5 (I don't think that number even exists...) you'll have trouble starting. But, that is a "racing" plug which is fine once you are on the track.

Let's just say the compression is fine and you are using a bad gauge... Detonating right when you give it gas above idle doesn't sound right. Something is very broken. It probably can't be detonation at such a low load & RPM. Perhaps a coil has gone bad.

What are the specs on the car?

j9fd3s

iTrader: (3)

60 is low, possible there is a bad gauge, if the compression had 6 EVEN bounces, that's more important than the peak reading.

i think you also need a timing light, moving the CAS around randomly isn't helping

Madcar

Cheers for the replies
Sorry, meant colder plugs. Yes they are/were NGK 10.5 (R7420).

On the warmer plugs now.

Specs:

Greedy KKK Turbo, Low comp rotors, 3mm tips, lightweight flywheel, bosch fuel pump. Tons of other stuff that probably isn't relevant

8 Months ago it started like a treat, first click of the motor. Can't remember when it became hard to start, I think after my starter seized up... Today it started sounding like it wanted to detonate. I agree, detonating just over idle, I didn't think was possible but it is very quiet, once you give a bit of gas and the motor starts working then it's a real loud crack.

The rev counter also started jumping and once over about 1700 rpm jumps up and over reads by about 2-3k?? THe Microtech reads the rpm right though?

I can easily swap the coils, may try that first thing.

beefhole

iTrader: (29)

Is the microtech telling you that RPM or the gauge? Sounds like the trailing coil is going crazy. If you overheated perhaps you detonated on the track too. A little too much heat....

Madcar

I did the timing using my timing light looks bang on to me, first mark on the pulley lines up with the pin on the block.

Madcar

Yea, on the track it overheated because of lack of airflow, had a great big intercooler in front of the oil cooler and in front of the RAD. I have re designed the setup now and have done a custom V mount setup.

The microtech is reading the correct RPM, the tacho is going crazy.

beefhole

iTrader: (29)

Tach gets signal from trailing coil. If the tach is going nuts, the trailing coil is going nuts. It could be firing early/erratically and making the engine "detonate" because the split is doing some strange things. I'm no expert though, but it no longer sounds mechanical to me.

Madcar

beefhole, I like your thinking. I'm going to try replacing the trailing coil.... It is strange the problem (detonating) started the same time the tacho started going nuts... I can live with the hard starting for now (put a big battery in the back)

Fingers crossed!

Thanks

ROTAge244

I've had the same exact thing happen. Trailing coil malfunction, replaced it and everything smoothed out. Replaced the plugs (mine were fouled) and she ran like a top.... fmic FTL...

bumpstart

CAS stab is all wrong,, the ECU needs a 30 degree window AFTER seeing the pickup so it can adjust the timing
if you line up the cas pickups with the timing mark you will be 30 degrees LATE with any timing

the G tooth ( home, 2 teeth ) should have PASSED the pickup and effectively be one tooth more on the NE ( 24 teeth )pickup
this makes the ECU see the home trigger early,, and give it a 30 degree window to adjust the timing
( ie idle timing will be 30 degree retard after the G pickup passes ,, and full advance may only be 5 or less degrees after the G trigger )

all ECU's work like this ,, needing to see a "window" of timing period after the G pickup
the mtech has a fixed trigger tooth and reference angle in its firmware,,
so you move the CAS with timing lock on under a timing light to finish the procedure

motec and haltech will have CRIP and CRIT ( motec ) or trigger tooth and reference angle ( haltech )
which allow you to adjust the timing window and set up the calibration with timing light

Madcar

Hello everyone

Thanks again for the help here, I changed the trailing coil and for good measure the leading just in case. I thought I'd fixed it, the car ran very well for about 10 mins and then started to detonate.

I managed to start the car, do one run but as soon as I finished the run (1/4 mile) the car would start to detonate from low revs upward. It seems that once it's been run hard for a few seconds or normally for a few mins it starts playing up.

bumpstart - Thanks for the info, this could be my issue, I did not use the timing lock to time it up. I have no info on how to do this with the Microtech so any more assistance you'd be willing to throw my way would be appreciated.

I do not understand the G tooth or the timing lock unless you mean the ground wire by the coil?

Would really appreciate some help on the timing as I have no idea where to start or how to do it.

Thanks In Advance.

john ward

iTrader: (7)

I dont recall which screen its on but scroll through screens and youll see timing lock. Select that then set timing with light. Make sure you remember to turn off timing lock when finished.

bumpstart

calibration of timing is in the manuals and you can google that easily enough
be aware that if set up as directed in the manual then the 5 ATDC leading mark is effectively zero datum for the timing maps
(IE- so that Tmax = 30 is really 25 BTDC )
and that if you use my posted method by marking the pulley for 10 BTDC and the static timing to 10 during timing lock
then that gets you a timing stab that reflects always true crank degrees from the maps

when its done right your dizzy should be like this-- note the 2 tooth G sender is past its pickup
and the Ne ( 24 tooth ) pickup is 1.5 teeth in
,,, a subtle hint that the ( fixed in the firmware ) reference angle is 45 degrees


depending on how the CAS dropped home on install the CAS may wish to sit at either end of its swing --- or dead in the middle

i highly suspect your CAS may wish to rotate to the full position in its current stab

you confirm thus with timing light ( micro method ) by setting the static timing to zero, locking the timing and cranking the engine
( can be done running or cranking with fuel pump disconnected )
twist the CAS till you match the timing mark to the pin

if you dont have the travel you require it is best to restab the CAS
and you may find it easy to drop home i you stop the motor just a few degrees short of the timing mark when you drop the CAS in with dots/dash lined up

Madcar

Hi everyone, thank you for the help on this. I have since raced and blown my motor and I have now rebuilt it... I don't want to start another thread but may do with a better title.

Can anyone help with that long standing problem of not being able to start.

Before I blew the motor it was a real pig to start as I mentioned and in fact I had to strap in an extra battery to give me enough goes at starting it. Now it has been rebuilt I still have the same issue.

It will turn and turn etc occasionally firing a bit and fuffing but it just wont start. The timing looks pretty good now after following bumpstart's guide there and the microtech sees the 30 deg split when you rev her up, otherwise sitting on 0.

It will start with a pull start and then proceeds to run fine at about 1200RPM or above, anything under about 1100 is dicey and it will stall.

All ideas welcome, really hoping to be able to go on my track day next Sunday in France

FYI:

It has been Street Ported but has previously ran and started fine with this config.

THANKS in advance

RotaryEvolution

iTrader: (30)

first i've heard of timing the CAS late and i have never had any issues using the 5atdc mark.


anyways, a quick test would be to disconnect the trailing coil and see if it clears up and vice versa with the leading. the car will run ok with either or but a bit worse on just the trailings.

it sounds to me that you could just have a dead motor also, if it's losing that much compression then it could be passing combustion inside the motor which is igniting the next compression stroke prematurely.

Madcar

I have tried both setups, in fact I have tried everything...

I have just rebuilt the motor using all Atkins replacements parts. The compression is good.

I have a vid here to help: http://www.madcar.co.uk/images/cars/...X7/nostart.avi

It just will not start on the starter, do I need to get it rewound??

RotaryEvolution

iTrader: (30)

sounds like the timing is radically advanced still.

i'm scratching my head as to why you pulled the CAS out in the first place.

Madcar

Rebuild.

I killed it after my last race so just rebuilt it, dialled in the CAS and here we go again, same old problem I have had for a while. even got another starter

If anyone has a link or manual for the LT8-s or how to time to factory specs please share it as google is not producing.

Thanks
Chris

I hate to love my car! I also love to hate it!!

RotaryEvolution

iTrader: (30)

well you can just leave the CAS mount bolt out and rotate the CAS one tooth clockwise each time you attempt to start it to get an idea of what is going on with the cranking timing.

and charge up your battery a bit more, it sounds a bit on the weak side.

walken

iTrader: (6)

same problem? I'd say ditch the microtech.

bumpstart

just pull the CAS up,,, disconnect the coil wires and rotate the CAS with the ignition turned on

this will simulate very low rpm ( below cranking rpm threshold ) and will demonstrate what micros and some other ecus will do during cranking

usually you will not get a trailing spark
( cause the low rpm default is non sequential injection and leading only ignition )

but on some,, and i did have this just recently on a older digi 2
is that some fail or glitch ( i suspect in the Ne , CAS multittooth pickup count ) will default the spark event to only the leading 1 coil , once per revolution,, and only on the G pulse pickup

( ie,, no matter what timing trim,, what static timing,, what cylinder selection ,, it will only fire L1,, or in the case of the digi2,, the dual coil,, but only on the L1 home pulse

this makes for very early locked timing and on one rotor only
,, and may clear when the engine catches ( on one rotor ) and gets rpm high enough to increase the Ne signal intensity for the system to see all the counts and actually present the correct timing window

i am with that,, cant have random **** happening in competition,, not good fro results or wallet
myself would think that the issue is likely CAS gap , CAS pickup,, signal shielding,, or potentially a failed cap or zenner in the Ne signal circuitry and the average street user would nut it out

if its cost an engine,, its no longer a cheap and cheerful ECU,,, your finding out why some of us have shied aways from them

in the end little things like this often come down to quality of the loom and connections supplied with these units

bumpstart

its stopping the motor around TDC and it allows for those noobs doing it the first time to get the "twist back" as it drops home to work in there favour
if you do it as a noob at the 5 atdc it is often a 50/50 bet if it drops in the right tooh or back one

myself have stabbed about eleventy billion of them and dont really have any issue with it as i know well enough by eye with CAS and dizzy


BTW

if you actually have the CAS cover on ( the right way up ) and you pull the bung,, if you have stabbed it right the G tooth is visible under the bung,,,, thats what it is for


also,, if you align up the CAS dots on the gear ,, you will see the G tooth is through already,, and its ready no2 Ne tooth