Timing and alignment

[menzzer37]

So I've been trying to get my megasquirt setup running and I think impropper cam alignment may be the issue. I keep getting inconsistent backfires. Here's how I timed it:

 

crank key up #1 TDC

Cam pin up (old chain) gear on #2 pin hole

Line up bright links on dot of crank sproket and #2 dot on Cam sproket.

 

When I crank it over with a breaker bar and my finger over the #1 plug hole, it stops compressing a little before the cam key is straight up. Does that mean the timing is off?

 

Does that mean the valves open just before TDC?

 

Also, the timing mark on the damper is a little to the right of the 0 on the timing marker. Could this be a chain stretch problem?

 

Any help would be great. Thanks!

[kolonelklink87]

has the cam timing been changed during the install or is it the same as before?... if not i would be more suspicious of your VE tables... there's plenty of good ones for l28's on here but you need to make sure your table matches your injectors etc... if this is the problem let me know and post your specs etc.

[menzzer37]

Yeah it's a fresh build, but the VE could be off. I have one that I've gotten off here.

Here are the engine specs:

300zx turbo injectors (280cc i think?)

t3/t4 intercooled

EDIS

240sx TB

GM sensors

 

I've attached my .MSQ

 

Also, I'm running 97ish KPa while cranking. Is that normal?

280z august.rar

[menzzer37]

bump

[menzzer37]

I'm to the point of paying someone to come look at it. I'm in Warsaw, IN. It's about 2 hours from Indy and Chicago. Anyone close?

[kolonelklink87]

i wouldnt do that just yet.... injector size is important... make sure you know that for sure... where did the map come from? (link?)

 

run it at 2500 rpm for 2 minutes at operating temp then pull plugs and post pics?

[menzzer37]

it wont start, so I cannot run it... I have tried a couple of maps off here from cygnus and others, but the engine won't catch. I can get it to gurgle and backfire consistently now but it will not catch and idle. I bought the injectors over a year ago and I can't honestly remember what size they are. I've tripple checked the timing, rewired everything, tried iridium plugs and copper, and played with req fuel for hours.

[kolonelklink87]

if you still have the dizzy stick that on - now you only have to worry about troubleshooting on fuel

 

if your problem is gone then check your36-1 wheel is in the correct position....

 

what made you suspicous of the cam? do you still have the specs for it.... how could it have been moved? (was the head off??)

 

it should still run if the cam was a "little off"

 

 

since its a first start you'll n eed to double and tripple check you wiring... sensors not being hooked up correctly will cause this kind of splutter non-start

 

 

FYI - you may find 280's to be a little small for your application - i run 270's on my l26 N/A just fineeee.

 

*edit* this should really be treated as an MS troubleshoot unless you have a good reason to suspect the cam etc....

 

check sensors, rpm signal, map signal, spark, etc etc

 

i cant look at your msq for a bit as im not on my own computer perhaps posting on the ms sub forum would be more appropriate an yeild better responses?

[kolonelklink87]

a thought -

 

It might help to go back to basics a bits here... could you datalog your cranking and post?

 

manually checked for injector firing?(wet plugs etc?) manually checked for spark?

 

If you have the "flood clear" function engauged it might help to turn that off so you can do some throttle play during cranking... my MAP usually drops 80-60 during cranking *i think*.... hmmm

 

 

i sure hope someone more knowledgable than I would jump in here *twiddles thumbs*

[z-ya]

Timing:

 

- Have you verified that the timing tab aligns with the mark on the pulley when #1 is t TDC?

- Have you verified your crank timing with a timing light (does it match your crank timing setting in MS)?

- Can you change the timing in your timing table and see it change at the crank with a timing light?

 

Do these checks with the fuel pump fuse removed or the injector plugs pulled.

[menzzer37]

Thanks for your help guys. I have posted in the msq forum, but nobody has really taken any interest.

 

I rebuilt the motor so the head has been off, but I'm pretty sure the timing is right.

 

A timing light won't work with edis as it will flash on top and bottom since it's wasted spark. At least that's what megamanual says. I dont have a timing light and havent bought one since I read that (maybe that's wrong, I could be mistaken). My damper has slipped, so I'm not sure the timing mark is accurate. I'm going to go through my injector wiring today and see if I can troubleshoot.

[menzzer37]

IT LIVES! Thank you guys for all your help. Turns out, my ignition fires CAB not ACB like megamanual says. A member sent me a pm and told me to try flipping the coil and it worked! She loud, smelly, and beautiful. Thanks again

[z-ya]

Get a timing light and verify your timing before you do anything else. Yes, you can use a timing light with wasted spark. If you don't calibrate your ignition system you are setting yourself up for a major meltdown when you start pushing it with boost. Without doing this calibration step you have no idea if the timing in the timing table matches the actual timing.

 

Fix your timing tab/damper while your at it. Doing is right now will save you a lot of headaches later on.

 

Pete