What's your MAP values at idle with XFI?

[norbs]

Nice table, whats CRS?

 

[Chuck Leeper]

It's..

Nice table, whats CRS?

known as "can't remember $hit"!!
Never fear, my friend. Some day, you too, will experience this disorder!!! :tongue:

 

[turbojimmy]

Didn't I see somewhere that someone had found that the harness had a wire out of place??
At my age, CRS is a constant problem... Maybe I didn't see that...But, I did see this:
Fisher Scientific UK - Pressure/Vacuum conversion table
A handy conversion chart!!

Yeah there was something goofy with the stock harness and adapter I was using. And the EGR was leaking. Putting the MAP inside the car fixed it. It still idles rich, like it did before, but nothing like it was doing. At least there's no visible smoke now.

Target A/F at idle is 12.something. It was 9.xxx before I 'fixed' it, now it's 10.5xx or so. Still rich. For fun, I told FAST it had 90 lb. injectors and it idled very nicely, right around the 12.xxx target. But as soon as I touch the gas pedal it stalls (because it thinks it has 90# injectors).

So I'm thinking I need to goof around with the VE at the idle speeds. Might have something to do with the 218/212 cam. Off idle it's great, though.

Jim

 

[turbojimmy]

I get about -7.5 psi at idle with a 224 cam unless yours is bigger its not possible to get your numbers

What's your actual A/F at idle and target? I have -8.8 PSI at idle now, but it's still pretty rich at idle. MAP values are in yellow still - not sure why.

Jim

 

[norbs]

target is about 13.8 and it runs about 13.4-6 ish. If you have -8 your doing quite well compared to what you had before..Whats your ve#s at?

 

[turbojimmy]

target is about 13.8 and it runs about 13.4-6 ish. If you have -8 your doing quite well compared to what you had before..Whats your ve#s at?

In the Base VE table? If so, it's 38 at idle. I can trim those back to get to the target A/F. When I do that, the idle picks up but it doesn't run right when I drop it into gear. But that's probably because I just changed the values where the bubble was. I probably have to make adjustments for a wide range of MAP values at idle RPM.

Jim

 

[turbojimmy]

I swear to god I'm going to set this thing on fire and laugh maniacally as it burns.

I found the EGR was still leaking. Fixed it.

Using a stethescope I found another leak at the vacuum block. Fixed it.

Yet there is still this 'whistle' at certain RPMs, under a load. When driving along I can hold it and hear it. Has to be a vacuum leak.

A/F ratio is 10.5:1 and my clothes stink, lungs hurt and the house smells from letting it idle. 02 correction is -10.2% (max). When I change the max correction to 25% it rockets right to 25% but it has little effect on the AFR. MAP is -8.5-8.8.

I tried a .gct file from another forum member who has almost the same mods as me. The car won't even run with it. My Cotton's base configuration is at least able to work with whatever the problem is.

Any ideas? I might just take it to my engine guy and have him sort it out. It hasn't run right since I dropped the engine in back in July.

[ whine ]Yet another race season is coming to a close and I haven't been to the track once. There's really no point in owning the car.

And, the tranny in my daily driver needs to come out because the friggin' TCC solenoid is bad. Thanks GM! Even after 25 years of trying, you can't manufacture a TCC soleniod that can last the life of the vehicle. [ /whine ]

Any advice would be greatly appreciated.

Jim

 

[Chuck Leeper]

Have you..

tried some WD, or carb cleaner around the injector bases?? O'ring fubar??
Time for a "smoke test". & NOT one that begins with pouring gas over the engine!!
What do the data logs look like?
NE "goorus" looked at the .GCT, logs??
In car boost controller hoses leaking?
Plenum, intake, or T/B gasket fubar?
I see a "12. something" for idle A/F. Why that fat? That's a good afr for an N/A engine at full load.. Maybe high 13, low 14 would be good.

 

[ALVAROG1983]

I have the same problem my clothes stink, lungs hurt and the house smells from letting it idle. I'll see if i can get a chance and plug my lap top and see what my numbers are at hopefully your extra input can help me get more familier with xfi because about to light my car on fire also i can see your pain. If you can Jim pm your phone number i'll call you its free from my end.

 

[ALVAROG1983]

dam

DO NOT plug and unplug the IAC with the key on.
This will burn up the IAC driver in the XFI box.

thanks for pointing that out i could of easily ended up like Jim now correct me if i'm wrong if the iac driver is burn would that cause the cars idle off.

 

[turbojimmy]

thanks for pointing that out i could of easily ended up like Jim now correct me if i'm wrong if the iac driver is burn would that cause the cars idle off.

I unplugged my IAC hoping it would help with the rich idle. But all it did was bake the IAC driver on the XFI and cause me to have to wait to have it repaired. They fixed it under warranty, though.

But I still have the same problem. I can't figure out what went wrong. It was working great for a short period of time but now it's fubar'd.

I'm going to grab my brother's stock ECM and MAF to see if I can get a decent base-line then switch back to the XFI.

Jim

 

[turbojimmy]

tried some WD, or carb cleaner around the injector bases?? O'ring fubar??
Time for a "smoke test". & NOT one that begins with pouring gas over the engine!!
What do the data logs look like?
NE "goorus" looked at the .GCT, logs??
In car boost controller hoses leaking?
Plenum, intake, or T/B gasket fubar?
I see a "12. something" for idle A/F. Why that fat? That's a good afr for an N/A engine at full load.. Maybe high 13, low 14 would be good.

Haven't tried much except listening with the stethescope.

I haven't logged it recently. An older log, when I first put the XFI in, looks good. But now the 02 correction is maxed out and it's running stupid rich. Can't figure it out.

No gurus looked at it yet. I'll have to find a local.

I could lean out the idle in the software, but it can't get it down to the current 12.xxx right now. 10.5xx is the best it can do.

I'm confused about why it's so rich. A vacuum leak should make it lean - I thought that I should be able to see that in the actual AFR. But instead it's dumping fuel into the mix and making it really rich.

Jim

 

[bison]

Maybe an injector leaking or some other way un-metered fuel is getting in the engine? I once saw a fp regulator that leaked through and the sensing port was sucking fuel in the engine .

 

[Chuck Leeper]

A common

Maybe an injector leaking or some other way un-metered fuel is getting in the engine? I once saw a fp regulator that leaked through and the sensing port was sucking fuel in the engine .

problem on some GM Vortec trucks, and LT1's.
No reason it can't won't happen w/ a TR, as Bison has said.

 

[turbojimmy]

problem on some GM Vortec trucks, and LT1's.
No reason it can't won't happen w/ a TR, as Bison has said.

I'll check that out. Also need to do the smoke test. It has to be a big leak - I just had the car out again and can hear the whistle. Just can't find it.

Jim

 

[Chuck Leeper]

Since you were working around the pass fender area, might you have broken off the plastic feed that goes to the heat, A/C???

 

[turbojimmy]

Since you were working around the pass fender area, might you have broken off the plastic feed that goes to the heat, A/C???

Could be. I'm going to point my fog machine into it to see what happens. It's a good sized unit that makes A LOT of smoke. Won't be able to get to it until later this week tho.

Jim

 

[Blazer406]

I swear to god I'm going to set this thing on fire and laugh maniacally as it burns.

I found the EGR was still leaking. Fixed it.

Using a stethescope I found another leak at the vacuum block. Fixed it.

Yet there is still this 'whistle' at certain RPMs, under a load. When driving along I can hold it and hear it. Has to be a vacuum leak.

A/F ratio is 10.5:1 and my clothes stink, lungs hurt and the house smells from letting it idle. 02 correction is -10.2% (max). When I change the max correction to 25% it rockets right to 25% but it has little effect on the AFR. MAP is -8.5-8.8.

I tried a .gct file from another forum member who has almost the same mods as me. The car won't even run with it. My Cotton's base configuration is at least able to work with whatever the problem is.

Any ideas? I might just take it to my engine guy and have him sort it out. It hasn't run right since I dropped the engine in back in July.

[ whine ]Yet another race season is coming to a close and I haven't been to the track once. There's really no point in owning the car.

And, the tranny in my daily driver needs to come out because the friggin' TCC solenoid is bad. Thanks GM! Even after 25 years of trying, you can't manufacture a TCC soleniod that can last the life of the vehicle. [ /whine ]

Any advice would be greatly appreciated.

Jim

Let me get this straight... so I'm not confused..... you have a target AFR set around 12.5:1 or so at idle....... and you have tweaked the VE table at those idle cells.... to get where the thing will idle.....


I am assuming:

• You are in closed loop since you do have O2 correction going on

• You have a target AFR around 12:1 or 12.5:1 for idle

• you have tweaked the Base VE table cells (might need to tweak 4 cells or more to have idle covered)

• Your O2 correction limits are set wide enough to let it correct if it wants to....

As I understand it... you cannot get it to idle above 10.5:1 or so..... how are you tweaking this? I assume with the base VE table?

A vacuum leak on a mass air car will definately cause a lean condition.... however it might not have as pronounced effect on a speed density setup like you would be running with a FAST system.


What values do you currently have in your idle region of the base VE table?

Can you send me a GCT file and a datalog of the car idling?

I'll give it a look.... can't gaurantee anything... but I will look at it anyway...

 

[callmeebryan]

Jimmy, send me your gct file with a log of your car at idle.

And tell me what size injectors and what cam you have....

Ill see if i can tweak it a bit for ya. I fixed another guys idle this way.

Your car shouldnt be idling in closed loop. You want it to be idling in open loop.

 

[turbojimmy]

Let me get this straight... so I'm not confused..... you have a target AFR set around 12.5:1 or so at idle....... and you have tweaked the VE table at those idle cells.... to get where the thing will idle.....


I am assuming:

• You are in closed loop since you do have O2 correction going on

• You have a target AFR around 12:1 or 12.5:1 for idle

• you have tweaked the Base VE table cells (might need to tweak 4 cells or more to have idle covered)

• Your O2 correction limits are set wide enough to let it correct if it wants to....

As I understand it... you cannot get it to idle above 10.5:1 or so..... how are you tweaking this? I assume with the base VE table?

A vacuum leak on a mass air car will definately cause a lean condition.... however it might not have as pronounced effect on a speed density setup like you would be running with a FAST system.


What values do you currently have in your idle region of the base VE table?

Can you send me a GCT file and a datalog of the car idling?

I'll give it a look.... can't gaurantee anything... but I will look at it anyway...

Yes, it's in closed loop at idle.

Target AFR is 12.5 (or thereabouts). It's idling at 10.5. MAP values are yellow, target IAC is yellow, RPM is yellow. I have the throttle blade the whole way closed. If I change the values in the VE table to get the AFR at idle where I want it, it will stumble and stall as it tries to transition out of those cells.

I've widened the 02 correction parameters to the max it will allow (-25%) and it goes right to that max. AFR gets into the 11s when I do that.

For fun, if I tell it that I have 90# injectors the idle clears up very nicely, but obviously it won't run this way. As soon as I move off of idle it stalls.

It worked when I first installed it, I'm not sure what I did to it.

I'm out of town the next few days and won't be able to goof around with it until Thursday or Friday.

Jimmy, send me your gct file with a log of your car at idle.

And tell me what size injectors and what cam you have....

Ill see if i can tweak it a bit for ya. I fixed another guys idle this way.

Your car shouldnt be idling in closed loop. You want it to be idling in open loop.

Why don't I want it idling in closed loop?

I appreciate your offer, but I won't be home until later this week. I do have a couple of log files I can send you an Blazer406.

Thanks,
Jim