Well, I got everything up & going....kinda.

Problem now is I have to retard the timing so far to get it to even fire it isnt funny.
The #8 location on the cap is retarded past the #1 spot(the rotor does point to #1 on TDC & the timing is MUCH worse than when I had the #30's in there). It is running LESS than before. BUT it sounds much better with the #24's in there..no flooding at all. Problem is it WILL NOT stay running. I got it to fire for 15 seconds at the most at one point.
I turn the key & it fires right up, but it just will not run. I put the dist cap on & line it up with #1..nothing. Retard it to where the tach & bat connects hit the firewall then she fires up & dies.

YES, I degreed the cam during reassembly, adj'ed the valves ect..
Got the fuel pressure set at 42psi(vac line disconnected) for right now.

Could it be the ECU pulling the timing that much? I have tried it with the stock chip & the Thermomaster chip with the same results...nothing. I'm pretty sure it is time to give pcmsforless a call. BUT, want to make absolutely sure this is the problem, or atleast find out if the ECU can pull the timing this much at START UP.
I confirmed that the spark & fuel are still present when the car shuts it's self off. Ofcouse it will not idle long enough for me to check timing.

Any ideas? I know the engine is mechanically sound & everything is adj'ed properly & all sensors are good. Dist is good. New module, cap coil, ect(yes they are good, I checked them)..
Only thing I can possibly think it could be is the ECU.

TIA


Link to video
http://storeandserve.com/download/9...CF1149.AVI.html

 

I don't see a single refence to setiing base timing with a timing light. Have you done this with the Brown/white wire disconnected? If so what are you setting the base timming to?

 

I CANNOT get it running to set timing. That is why you didnt see it.
BUT, I did say this...

" Ofcouse it will not idle long enough for me to check timing."

 

Did you diconect the EST wire? That is step one. If you think the ECM is pulling timing this wil solve the problem. I would say you have the distributor in wrong but you state that the rotor points to #1 at TDC so you should be ok.

 

Yes, it is disconnected.



Sorry, I wanted to say that it wont even fire up with it disconnected.
I hit enter to early.

 

ECM shouldn't be pulling any timing at start up, the timing should be at the base 6* when starting. (once it is set)

Sounds like you have the distributor in wrong or you have a massive vacuum leak.

 

edited my last post.

I know for certain there are no leaks & the dist is in properly. The only thing I am unsure of in the ECU controlled TPI's is how the ECU interacts with the engine.
I have built MANY SBC's & have dealt with MANY HEI's....just not computer controlled.

 

I'm going to upload some video I just took. It'll be a few minutes.

 

This link might give you some more insight on what the ECM is doing at start up. However, it doesn't appear to address timing.

Jeff

 

what cam did you install and do you have the specs Lift .050 duration and LS would be good.

 

Hummmm....... " Idle Air Mixture valve (located on the throttle body) may be misadjusted"

WTH is that? I cannot find ANYTHING to adjust on this.
Considering everything I did to it, not adjusting this could be a problem. I just cannot find it on the TB & it still doesnt explain the severe timing issue.
The only thing I could posibly see it being is where the little screw comes out of the TB where the linkage is (I thought this was fo ridle speed). Ofcouse like the other manufactures they put wax over the head so you cannot adjust it(take out the wax & then you can no problem).

Anyway. Here is a short vid of what I am talking about. Once I can find a way to make the vids a smaller size(38 sec is 42MB) I will do more.
But this is with the timing wire DIS-connected & the HyperTech Thermomaster chip. It now does fire up, but this is about it.
I move the cap in diffent spots so you can see how far in retard I have to take it.
ALSO note the fuel pressure gauge. It didnt do this intill AFTER I took out(well, it blew out) the core in the valve.

DSCF1149.AVI
or
http://storeandserve.com/download/91...F1149.AVI.html
I have never used megaupload so I am not sure on how it works.

I have a BUNCH of short vids(about 10-12 seconds) of me testing various parts of the problem, if you need or want me to post them I will.

It's the Comp cams XE268H-10(along with 1.6 roller rockers). I have used this cam before & know many who still do. I know it's good.

 

COMP CAMS XE268H-10
Lift: Int .515, Exh .520.
Adv duration @ .050: Int 224, Exh 230
Lobe seperation is 110
That is a prety hefty cam foe the stock tune. i know my 306 would not idle with the stock tune but unlike your situation I could keep it running as long as I kept a little throttle. I am a little unclear about your problem. Can you keep it running if you give it a little throttle? The IAC will only afect how the car idles once you give it any gas at all you are beyond any thing the IAC can do for you. The IAC is nothing more then a controlled vacume leak. It is located on the bottom of the TB where the cooling lines go through. That is acualy called the IAC housing.

 

Actually the lift on the cam is about 507/508(with teh 16's)
Yeah, I was thinking & discusssed it with a few people & the general consensus is the stock ECU cant really handle the cam. BUT, it should atleast start.. Besides for the ECU the only other part that is stock(unmodified) is the TB.
So the IAC & IMV is the same thing? As far as I know that isnt adjustable & doesnt have a vac going to it(just coolant lines which are bypassed). I had to take it apart & clean everthing out. New gasket & bolts went back on it. Plus if it was bad the car would still start (i've had MANY bad or unplugged in cars before & they ran fine). Just mainly for A/C & power steering operation(at full lock position)
As for giving it gas. It doesnt matter what I do. Just of idle, 1/4, 1/2, full..doesnt matter same result...nothing. Fire up & die. I can do this 4 or 5 times in a row & get the same result. Not flooding the car out anymore thank god.
Headers get plenty warm, so I know there is good combustion.
Everything is within spec that I have tested. I just made sure the valves were good again. Made sure they were not to tight(as we know that will prevent starting).
As for what I have done. A short list is here
http://forums.corvetteforum.com/show...ghlight=XE268H

Only addition I have done since then is headers(plus the #24's like I listed here).

Now that I think about it. I'm going to take the TB back off & check to make sure everything is good with it. Got me thinking about that gasket. Not sure how vac affects it. But i'm about to find out.

 

The IAC is on the passenger side of the TB down at the bottom and has a 4 pin connector going to it.
First you need to adjust the TPS (throttle position sensor) on the passenger side of the TB up top, 3 pin connector. Using a digital meter back probe or using pins, pierce the insulation on the top 2 pins of the connector. Set the meter to DCV. With the key on engine off the meter should read .54v +/- .017v, adjust the sensor to get this reading.
Next is to set "minimum air", think of it as a base idle.
To set it you jumper pins A&B of the ALDL and turn the key on (don't start the engine) wait 30 seconds then remove the IAC connector THEN remove the jumper. Start the car, it will idle very low...probably too low for your cam. adjust the idle screw (driver side of the TB) to get a higher idle. You're going to want to adjust the idle as low as you can (no lower than 500rpm) and still have the car running. then you go back and adjust the TPS again.
Once this is done you are ready to try starting it again. Make sure everything is connected and clear of the engine.

 

Morley, Thank You. I will definitly do this.
I had the TPS set already( .55V). But the rest. I had no clue.

Follow up in the morning.

 

If you are turning the distributor til the wires hit the firewall you are advancing it, not retarding it. Or you have the distributor in 180 degrees out of sync and your battery/tach wires are on the passenger side of the car?

 

Yeah, your right. Dont ask what I was thinking...or actually wasnt thinking. Everythign is in properly.

I'm going to sleep now.

 

Well, more bad news.

I only have power to C-pin on the ALDL. Plus I have a pulley squealling like a pig, so I have to figure that out now.

New thread started here
http://forums.corvetteforum.com/show...88&forum_id=48

 

I'm not an expert by any means, and it's obvious with your mods that you know a lot more about this than I do, and you may not even have a MAF sensor. But a while back, my vette (87 stock L98) would start but it wouldn't run (would die after about 2 seconds). The problem was the MAF sensor. The problem happened without any warning ... car ran fine, turned it off, next time I tried to start it, no go. The diagnostic section in the FSM says that if you unplug the MAF sensor, the computer will use a default value. With mine, the engine would run with the MAF sensor unplugged but wouldn't with it plugged in (until I replaced it). Might want to give that a try.

 

Well, ummmm
Humm. This is interesting.
This is done with the Key on Engine off...

I was checking all the ECU pin-outs. Have power going into the ECU Via the two orange wires on B & C.
Here is where I am at a loss. I'm looking at the schematic in front of me.
The wires that are supposed to have power do not. C3-C6, C12 & 13, ect.. No power(no power at ANY sensors also). I have the DVOM grounded properly when taking the reading. Now, when I have the POS on the DVOM connected to a orange power wire. I get power to ALL the wires except a couple when I touch them with the neg. How the hell can this be? This would mean ALL the wires are grounding out...no?

The only wires that are not grounding are the injection, dist, CEL, AIR(to ALDL) wires...go firgure. I guess this is why it fires up & stalls.

How in the world can these wires be grounding themselves out? Through the ECU its self? This would definitly explain why I have no 2 sec FP, constant cooling fan operation( grouning out?), no TPS, IAC voltage, amungst others.

I took the ECU board out of it's case looking for signs of obvious damage & found nothing melted, burned or other wise.