Why wont my car run longer the 5 seconds.

[Daws222ooo]

Im very new to tuning and im trying to get a head start for my tuner. My problem is my car only runs for a couple seconds then stalls. Sometimes it wont start at all. What I have is a 97 corvette forged 6.0, 8.5:1 comp, ported 317's with patriot extreme springs, ported polished ls2 tb, vic jr intake, Aarons elbow, 83 siemons injectors, RSI Dual fuel pump set up with return and boost referenced reg, alky control with a 10,15 nozzle, comp cam 227-223 on 115 lsr lobe, Hinson front mount turbo with 76mm precision, all hot side swain tec coated, ecs intercooler, dry nitrous setup, ls3 slot style maf (unplugged) with 4" pipe from cooler to tb relocated iat sensor, f.a.s.t 3 bar map, msd 2 step, Dewits rad and fan 160 stat, flt level 4 trans with a super yank 3500 stall, dte diff with 3:90's.

Sorry for it being so long but im trying to give as much info for the tune. Most recent mods were I repined my ecu to 02, took out 60lb and put 83lb injectors, relolcated coils to fenders, went from snow to alky control. My concern is it ran fine before these mods and im hoping its in the tune and not rewiring it wrong. Im thinking its the tune because it does start a run for a bit. Any help or guidance would be appreciated. Thanks, Eric16286

[darcy]

Start by fixing the Out Of Range cells in the tune. Not sure how these could have gone OOR..... Were they are problem in the tune you had in before?

I know you said it ran ok before, but your VE table looks low everywhere to me....

Do you have a log of it not staying running?

[Daws222ooo]

I will do that and get a log. This is a totally different tune then before. Before it was a 97 operating system in hp tuners with a 2 bar map. Now the car has been repined for the new pcm 99+ for better tuning abilities and 3 bar. Also that is a totally different ve table then my old tune. Thanks for your help I will give it a shot. Eric

[joecar]

Do you get any DTC's...?

What MAP sensor do you have...?

[Daws222ooo]

I have a fast 3 bar map I believe, I bought it from speed inc about a year and a half ago. I was able to use it as my operating system wouldn't allow 3 bar. It didn't come with any data so I have the scaler set to 288 and 1.5 offset. With key on engine off it read 101 kpa. I'm not sure of any other way to calibrate it. The only dtc I'm getting is crank relearn which I can't do until it runs longer. Also some abs dtc probably from installing line lock and larger rear calipers which shouldn't effect start up, I don't think. I'm thinking maybe map sensor info is off. Idk maybe I could put a stock map in with known values.

[joecar]

When you applied the COS, you did not edit B3647 (it looks just like the the old B3605)...

in B3647 take a look at the commanded EQR at 400 and 800 rpm in the idle MAP range (say 40-50 kPa), it is commanding overfuel, fuel is pooling in the intake maanifold causing your engine to stall a few seconds after starting.

Also, fix the OOR cells that Darcy pointed out, see here:


Fixing Out Of Range (OOR) Cells:
help-kr*-problem (http://forum.efilive.com/showthread.php?9931-help-kr*-problem) post #14
3000-RPM-max-and-setting-codes-03-Z06-with-Magnuson-at-150kPa (http://forum.efilive.com/showthread.php?14119-3000-RPM-max-and-setting-codes-03-Z06-with-Magnuson-at-150kPa) posts #14, #17
I-need-help-getting-the-most-out-of-my-car (http://forum.efilive.com/showthread.php?14654-I-need-help-getting-the-most-out-of-my-car) post#2

[Daws222ooo]

I never touched the ve table. What I did was I paid for a mail order tune, then its suppose to get tuned my me logging it. I just wanted a start up tune for now just to verify the mechanical aspect of it, then when weather get better finish the tune. Well here I am so far I had to change, injector data, map, vehicle parameters, disable vats, fix oor cells, now ve and other things also. The person tuning my car is a very reputable tuner and is very good at what he does. I'm not happy with the tune I was sent at all, Im guessing it was just a random saved one he had. Also I am not pushing the issue to much to him as I'm learning along the way which is good. I just cant believe the tune I was sent, just want a decent tune to start to eliminate anything else. So now here I am here is the new updated tune and a couple try to start logs. Im not sure why it wont go into sd, maybe just not running long enough?

[Daws222ooo]

162881628916290

[joecar]

B3647 is not the VE table... it is the OL commanded fuel table... when you start the enoine, it runs in OL until CL conditions are met... B3647 commands fuel during OL.

The COS introduces B3647 (EQR by RPM x MAP) which replaces OEM B3605 (EQR by ECT x MAP)... your _0001 tune file shows B3647 having the original contents of B3605.

Many people overlook editing B3647 after applying the COS.

I'll take a look at your_0002 tune file shortly...

[joecar]

To go into SD you have to get an immdiate MAF DTC... without a MAF DTC the PCM is still trying to use the MAF table (even if the MAF is physically removed).

[Daws222ooo]

Thanks Joe, what I'm wondering is why it's not setting the dtc and going into sd mode, I believe all my parameters are set up to fail maf and go into sd mode. Maybe the car isn't running long enough to fail the maf? On the other hand I wonder if it won't stay running because it won't go into sd mode. I thought I remember reading a while back some people were having issues in the cos getting there car in sd mode. There was a different approach of getting it there but can't remember how to do it. It was a bit ago. I talked to my tuner and is gonna go over the tune again, but I'm still trying to learn, so any help is awesome.

[Daws222ooo]

One thing I noticed is that I'm not getting any spark advance during cranking, a few times it did but not usually. I noticed a few people had the same issues on this forum but it was never stated what the fix was.

[darcy]

Set C2906 to 1, otherwise you need to see the low frequency trigger 6 times befog a code is set.
You said in the opening post that the MAF is unplugged - but it's still reading. Set C2904 to a big number, say 12000 if you're going to leave it plugged in, otherwise you won't set a code.

There seems to be a bigger issue, probably not tune related. Logged engine speed is 0 RPM for most of those 2 logs - nothing is going to happen if the PCM sees no engine speed. At the same time MAP pegs at 101.

Have you got any logs where it does run for a few seconds?

I'd be leaning towards possible physical/electrical issue.

[joecar]

MAP static at 101 kPa (BARO) -> indicates no compression/vacuum during cranking.

RPM static at 0 rpm -> indicates no signal from CKP and/or CMP sensors, PCM does not know engine is turning.

[Daws222ooo]

Ya I tried it unplugged and plugged in. Here is a log where it was actually showing timing and rpm. Its like it will run for a bit right after I reflash it then it wont. I Leaning toward electrical. What deters me from that is that it does run for a few seconds sometimes. Almost like something is killing it. Maybe map settings are not correct, or vats. Im going to change that maf setting like you said, and enable vat and do a vats relearn. If that don't work test wiring circuts, or put stock tune with stock inj, map, and maf, to elimate tune.

[Daws222ooo]

16298

[Daws222ooo]

Well it's up and running:thumb_. My tuner sent me a new tune made a few changes and now it's running. One thing I noticed was my pcm wasn't showing a vin so I put mine in, not sure if that matters or not but its running now. I'm thinking there may be a loose ground though as it was running for about 10 mins then it just died the fuel pumps stopped working. They wouldn't turn back on, I then read my tune from the pcm to make sure I saved it and when I did I heard the pumps cycle again. Now there working fine again, not sure if it was a fluke. I will check them over any way. Thanks for your help guys.

[joecar]

Check your grounds again (one on each side of engine block, one on rear on LHS head, and various chassis grounds).

[Daws222ooo]

Ya I defiantly will check them out. I actually added 3 more from the block to the chasis. My engine was painted with 4 coats of thick paint and I can't remember if I removed the paint where the grounds go. I will pull them off and double check. I'm just happy it's running now.