possible timing issues, long post :(

V8BUG · Post by **V8BUG** » Thu Jan 05, 2006 6:20 pm

MSII embedded code 2.1, megatune 717
Since my last post the car was running and idling around 1400rpm. The only problem was that the number 7 header tube was glowing red. I checked the valves and re-adjusted the rockers which were fine to begin with. Next I figure that injector might not be opening enough or opening to much.

So I pulled the fuel rail and the #7 injector and put 12v across it and heared it clicking. Regardless I think I will have all the injectors cleaned and tested since it was bought from ebay.(anyone know a good place to have injectors cleaned)

I got a hold of a stock tpi fuel rail and 305 injectors(19lbs opposed to my 26lbs accel injectors) from a friend.

When the engine was "idling" at 1400 rpm with the old injectors the distributor was set in with the vr sensor points lined up at 10 DBTDC (small cap 8pin hei) and the offset set at 10 in megatune. The ign advance guage displayed alittle over 20 of advance. I figure megatune was adding the offset and the table values to get the timing. When I would change the offset and make it higher like 15 or 17 the idle would come down and the advance gauge would lower. The opposite would happen if I lowered the offset.

Now with the new injectors I set the distributor at 0 DBTDC figuring the computer would give about 10 degrees at idle. Every carb car I have worked on I would set the distributor at about 10 DBTDC and thats what the advance would be at idle.

I let the megatune calc the req fuel with the new injectors. The engine would not start no matter what i did with the req fuel or offset.
Now I set the distributor at 8 DBTDC ( like I have on any other carb sbc) and the offset at 8. It still would not start. I played around with the fuel and offset, nothing. On the last test it was shooting some nice flames out of the throttle body!

attached is my latest msq.
I have searched the forum and the net and I can't find any other msq examples of a v8 other then the 80 something K5 blazer under MSII sucess stories( I am using his exact timing table) eevery time I search for msq file and in the post it says its attached I cant find anything!
If any one is running a v8 I would love to see your msq just to compair.
I think my timing table might be way off, anyways, any help would be great!!

Enthalpy · Post by **Enthalpy** » Thu Jan 05, 2006 10:23 pm

Two great places to have injectors cleaned:

http://www.witchhunter.com
http://www.rceng.com

Your issue doesn't sound timing-related at all. Concentrate on the basics. Make sure you have injector tick (via mechanic's stethoscope). Make sure you have rail pressure. Make sure you have spark. You might have disconnected something mission-critical accidentally while swapping the injectors.

V8BUG · Post by **V8BUG** » Fri Jan 06, 2006 9:43 am

I checked over all the connections and finally got it running. I still need to do some adjusting on the throttle blade or iac steps for it dies if I dont pump the gas.
I had my eye on the #7 header tube and low and behold it started glowing, then I looked around and #1, #2, #8 were starting to glow as well. I feel this confrims there is a timing issue. Does that mean the timing is to far advanced? should I take the timing table all down some?

aas · Post by **aas** » Fri Jan 06, 2006 12:09 pm

You maybe already have used a stroboscop timing lamp for cheking that you have the same timing on the crank and in megatune

Aas

V8BUG · Post by **V8BUG** » Fri Jan 06, 2006 2:11 pm

Since my only reference base is the sucess story of the K5 blazer under MSII sucess stories for how the timing table should look and the ignition setup should be I have basically copied what he has and I think its ok.

I have tried both trigger calc. and trigger return with no effect.

I cant get the engine to idle, it is almost impossible to start and when it finally does catch I have constantly keep reving the eninge. If I leave it at any one spot it will stumble and stale, if I try to let it idle it will stall. the ignition advance is somewhere in the 20's around 2000rpm which sounds about right. The distributor is in a 8 DBTDC with the trigger offset at 8.

I cant get a light on it since it will not idle and the headers start glowing in a matter of a couple minutes. I have a feeling the light and the trigger wizard would not match since that was the problem I had before(when I was running the old injectors) The light I am using is a non-inductance type, real old school, maybe its junk.

I am going to try and lean it way out, take the req fuel way down, and see if that makes a difference. Otherwise I am going to have my injectos cleaned. And if it still does not work right you might see my whole setup on ebay.

could the wiring to the distributor be incorrect? I am really picking my brian here, everything I have been trying seems to make it worse.

V8BUG · Post by **V8BUG** » Fri Jan 06, 2006 4:23 pm

distributor still at 8 DBTDC and offset at 8
I used one of the excel spreed sheets on the sticky post to calc a new ignition table.
max advance: 36
bore size adjustment: 0
fuel grade adj: -2
chamber adj: 0
idle advance: 9

thats what I plugged into the excel spreed sheet. the sheet said :
max advance above 3000rpm: 34
max total advance: 55
and the table in blue.

that yeilded a table in which I typed into the megatune table and fired up the engine. It ran real strong and crusied at about 2700rpm. If I tried to touch the throttle it would pop and shoot flames. he advance gauga in MT displayed about 52. I went into the trigger wizard and started to change the trigger offset. the idle came down but it still was at high 30's and was backfiring and poping like mad.

I went to that new table and knocked 10 off each number. It now crusied at about 2400rpm still poping and such.

I feel the timing is way off or something.
Does anyone have a example timing table?, any advice?

Jim Blackwood · Post by **Jim Blackwood** » Fri Jan 06, 2006 6:03 pm

If it helps you any the glowing headers were probably from the timing being too far *retarded*. It makes the mixture burn in the tubes. Had that happen to a motorcycle once. Totally ruined the chrome.

V8BUG · Post by **V8BUG** » Sat Jan 07, 2006 8:36 am

I went out there this morning an set the distributor in at 14 DBTDC and the offset set at 14. I got the engine running,I have to keep reving it or it will stall, and at about 1500rpm the ign advance gauge showed about 19-20 degrees advanced. I am using the table from the MSII sucess story of the K5 blazer. Ont that table at about 1500rpm and the according Kpa the advance is about 20ish. What happened to my trigger advance?

If I add my trigger advance to any number on the whole table it is greater then 20. Could the 5v ref signal to the hei module not be working? Do I have some setting in megatune wrong?

Please I need help

V8BUG · Post by **V8BUG** » Sat Jan 07, 2006 11:59 am

I gave up on tuning the timing with the wizard and now I started to move the distributor until it sounded better. I have it right now where it will run without the headers glowing. I also ended up taking the req. fuel quite a bit.
I got it to run at about 1500rpm and it would rev without poping or backfiring. At this rpm the ign advance is in the low 20's at about 40Kpa. I look over at my ign advance table and that is just about what it is. The trigger offset is still set at 10. Why is the computer not adding the offset into the ign advance?
Should I go through and add 5 or more degrees advasnce to every number on the table?