m20 stroker stumbles and quits (long, help)

[brody]

So black war chip is a bad thing?

Black isn't bad. It is our new hardware version of the WAR Chip. We have about 250 of the new black ones out there right now and only one has failed.

resolution,

so brody sent me a regular eprom chip to rule out any warchip error, which of course there were none. Id like to make sure im clear on this point that non of the miller products were at fault here, they are great products.

so i got the replacement chip in and started it up and it was the same deal. the only difference was in the timing of the shutdown. It was a hot day out ~94deg and the engine died much quick than it had when it was in the 70s, indicating something with the warmup enrichment. So i finally did what i should have done from day one of this thread and replaced the coolant temp sensor. I fired it up today and let it idle for several minutes and it did not die, i got it up close to operating temp shut it down and restarted it to make sure it took. So far so good, if anyone has similar problems go ahead and replace that temp sensor, its cheap and it could be the problem.

Thanks for your reassurance, and thanks for posting what you found.

[NC325iC]

resolution,

so brody sent me a regular eprom chip to rule out any warchip error, which of course there were none. Id like to make sure im clear on this point that non of the miller products were at fault here, they are great products.

so i got the replacement chip in and started it up and it was the same deal. the only difference was in the timing of the shutdown. It was a hot day out ~94deg and the engine died much quick than it had when it was in the 70s, indicating something with the warmup enrichment. So i finally did what i should have done from day one of this thread and replaced the coolant temp sensor. I fired it up today and let it idle for several minutes and it did not die, i got it up close to operating temp shut it down and restarted it to make sure it took. So far so good, if anyone has similar problems go ahead and replace that temp sensor, its cheap and it could be the problem.

[NC325iC]

i wouldnt say that, im not familiar with the issue he has mentioned but i would not go so far to say its a bad thing. need more information before making such a bold claim.

[billybobjoseph]

So black war chip is a bad thing?

[NC325iC]

its black (as you know from last nights email, im just sharing with the others)

[brody]

If he is having a CEL problem I am assuming it is the slightly older green WAR Chip from which the possible problem I was curious about doesn't exist. I haven't heard from him though.

[billybobjoseph]

I hope you guys come back and post the answer to this perplexing conundrum.

[NC325iC]

i can rig up a CEL, but last time it gave me a bad ecu code that you said was just the war chip firmware or something like that. ill check on the color and get back to you in email.

[brody]

What color is your WAR Chip? I would like to send a different one to you possibly. Just this week we had a customer with a 540 whos car died twice on him We thought it could be the fuel pump, while I was out testing it, it died. I noticed to CEL when I tried to start it again... There was something wrong with his WAR Chip. Replaced it and all was good.

Do you have a CEL to see if it has communication??

[billybobjoseph]

If it blow's however, your car wouldn't even start because the fuel pump wouldn't run.

[billybobjoseph]

Ah right, verts have the battery in the engine compartment. The legendary fusible link is on the smaller of the two positive battery cables, under the carpeting about a foot or so from the battery in the trunk - it's usually 50 amps.

[NC325iC]

forgive me, i was raised an e30 vert guy. What is this fusible link?

i will put an afm and stock chip in if i cant find another solution soon, im reluctant because it would require some un-rewiring, or another engine harness.

The thread title say stroker, but in the first post you say that the engine has:

stock i exhaust barring stromung muffler
stock i intake manifold and throttle
Miller PSIK and war chip with tune

I assume that you mean that it has:

I head, intake, throttle body, fuel rail, & injectors
I engine harness and DME
stock i exhaust barring stromung muffler
Miller MAF & WAR chip

The first thing I'd suggest is to revert to the I AFM and chip. That will pretty quickly tell if the problem is related to the Miller parts. If the symptoms are still present in that configuration I'd check the fusible link, replace the main & fuel relays with new parts and try a different DME. The symptoms don't sound to me like an problem with the exhaust so much as they sound like an engine management issue.

[billybobjoseph]

Unless it was SO high the pressure built up in the rail even with the FPR open but I can't imagine your pump doing that. Bentley says disconnect the fuel return line from your FPR and put another line in it's place leading to a container. Jump (fused jumper) the 30 and 87 plugs where the relay plugs in and run the pump for exactly 30 seconds. Should give you a minimum of 875 ml or 30 oz. No maximum value is given.

[billybobjoseph]

I think the thing that matters is the pressure. The brain tells the injectors when and how long to remain open and is calculated using the pressure the rail is supposed to have in it. If the flow rate was too high the FPR would open to maintain the correct pressure in the rail. If the flow rate was too low you'd have problems because you'd never reach the correct pressure.

[NC325iC]

just conducted one last experiment for the day.

alright so like i said i just ran it and it died, and like ive been saying the fuel pressure has been fine the whole time. I was thinking maybe i should test the fuel pump flow rate. so i went and i fired it up with the relay in place still, it fired up and ran (a bit rough), i then pulled the relay while it was running, it smoothed out a little bit after a second or so and then as the pressure dropped it died in the same way it has been.

does this tell us anything? perhaps its getting too much fuel causing the computer to over compensate? i dont know i just thought the results were interesting.