This is a new engine. 388 with HSR,patriot heads,roller cam
Using EBL/flash for tuning.
Set up my worksheet using 30 lb injectors so the BPC-BPC vs Vac is set to 154.
Start up the car INT/BLM =128 in OL

I go into CL and my INT has dropped down as far as 80 and BLM drops to 108. I made some adjustments to the LOW VE table but haven't gained any ground on this problem. Is there another table I should be using?

 

Is the engine OK with the AFR when the INT and BLM are that low? If so then you are on the right track. Other things that should be checked is the actual injector flow rate and the fuel pressure.

It may be that a lower BPC is required. Get it drive-able then see how the higher RPM and load fueling is.

RBob.

 

Engine AFR is running in the 11.4-12 range in both OL and CL

Injectors are the EV1 Redtops and my fuel pressure gauge is reading exactly 43.5

Definetly rich. I would try and drive it but as soon as I press the pedal it will stall and in order to restart I have to press the gas pedal all the way down. So I'm thinking I need to straighten out my idle first.

 

I've dropped the BPC down so far to 146 and I'm getting the same thing. Go to CL...INT/BLM's drop. Once I shut it off it floods and the only way to start it again is to press the pedal to the floor or I have to remove them and dry them out since there soaked with gas.

I've used two different fp gauges to confirm the correct pressure. The red tops are brand new from jon at fic and he did confirm they're operation before shipment to me.

Any ideas?

 

Dropped the BPC down even more same result. Runs real rich in OL (AFR 11.2-11.6) Goes into CL INT continues to drop to 87 while BLM is 108 (AFR is 11.6-12)

I've confirmed operation of the O2 sensor

Anyone have suggestions??

 

Start pulling fuel via the VE table.

RBob.

 

What cam is in the engine? First post states a roller, sig shows a flat tappet.

RBob.

 

Sorry about that I meant to change my sig.
Comp billet roller
Duration at 0.50 230/236
Lobe Seperation 110
Valve Lift .603/.609


Its a custom grind

 

With that cam going to need to pull a bunch from the low RPM areas of the VE table. There isn't going to be much volumetric efficiency there.

Most likely need to raise the idle speed. And will need to move the VE table peak up some in RPM.

RBob.

 

Idle is set from 950-1200
I thought the BPC would set my Low VE table?
So I"ll have to pull fuel out manually in those tables is what I'm understanding

 

Here's the latest update.
Been pulling fuel out of the Low VE table. Wasn't making a differance. I pulled out my brand new 30lb injectors an put in my old smaller injectors. Figured I'd try them since it was for idle only. Adjusted the BPC table and left my Low VE were it was. Started right up. INT/BLM's were closer in line. So I sent the Red Tops back to FIC. Following day went out and tried to start it. Within 20 seconds every plug was soaked in fuel. So there is something going on. I'm wondering if either I'm having a weak spark or intermintant spark plug so I'm going research that a bit today.
Also is there anything in the ecm I could have burnt out that may cause this symptom?
thanks

 

What sort of vacuum are you pulling?

I suspect with that cam it is fairly low, possibly unsteady? It may be falling to higher map regions in your VE tables than you realize, or if it changes enough activating AE, check logs.

 

With the vac gauge connected to the plenum I'm pulling 17Hg.

At idle my map is reading 55-70, depending on CTS value.

I was able to run it a bit longer today. About 6 min's in I threw a Code 33 (Map Hi) code. It had happened right after I reved to 2200 and it dropped back as low as 487 rpm. In turn given me the code.

Fortunetly so far today it is re starting... so I'm a little bit ahead

 

I thought so...

Along with my previous post consider that cam is going to want more timing advance than normal, that will help develop some more vacuum.

 

I thought anything over 14Hg is good?
Are you saying advance my Main SA table or Advance the base timing on the car itself?

 

Always work with programming for your timing, I set my distributor to physical 0*, any change to that would be for injector timing.

There are several SA settings involved, just work w/main tables until you have studied SA in detail.

All of the stock bins are set up for about 20 - 22in vac (HgV) or around 30kpa, your way off that.

 

I believe in "flags" or "constants" there may be a setting for high MAP so as to not throw that flag/SES. Move it up a bit?

 

Is this one of those cases where lowering the Idle O2 Window Terms helps?
What is the overlap on this cam? Just put new intake cams in my LT-5 w a
.236"@.050/.425" lift. So I have played w the O2 idle terms as I did with my Xfire. The cam specs are not impressive for a OHV motor, but definitely rumpity stuff for a DOHC.

 

Dom: Please elaborate. is this the rich/median/lean settings that the sensor cycles over? It is stated IDLE. Does idle have a specific constant for "swing" points vs off idle?

 

In the case of EBL, he answer is yes. There are a specific set of swing points dedicated to idle. My roller cam in my 84 had 53d overlap. When I first started it, it ran VERY rich at idle. Part of he issue was the overlap causing the O2 to report a lean condition thereby causing the ECM to add fuel. Lowering the O2 sensor swing point at idle, lowered the voltage(leaner) the ECM considered as ok or 128. By doing that, the ECM no longer continued to add fuel. I'm trying the same strategy with my LT-5. Many guys tuning LT-5s
just go O/L because most of the LT-5 defs don't expose the O2 sensor parameters. I'm looking to run C/L because of other tools that become available like PID controls.

 

Understood. My idle shows like 1.9-2.0 msec. 80 lbs at 20 FP WOT. VAFPR FP drops to like 11-12 I recall. WB reports 13.5-13.9 idle. I think i am OK.

 

Ron,

I was also running the BB 80# injectors. The Aeromotive VAFPR would range FP from 10# at idle to 20 at WOT. DC was somewhere in the mid-70% at WOT.

 

I guess I'm not understanding the problem I've having. Yesterday I ran it several times at idle. Not perfect but it would restart everytime. Today I started it up this AM to see if it would start and it did fine.

Made some minor changes and reflashed a .bin... within 2 seconds of cranking it flooded. Gas soaked spark plugs.

My ignition has tested fine, TPS was changed twice with the correct voltage. FP is 43.5, gas in the tank, I'm now on my third set of injectors so its not a injector problem.

What would cause the plugs to be soaked with gas within a couple of seconds of turning it over if I have good spark,fuel pressure,and the injectors are fine?

 

I ended up with VE in the single digits to keep mine starting/running. From my point of view, it looks like you've done everything I went through. Getting the idle down is a big PITA especially when you are fighting lower vacuum. It's surprising how little fuel a larger cam needs until it wakes up.

What are the minor changes you made? I'm very new to this and have changed a lot of things I should have left alone.

 

This cam really isn't all that radical and should be tuneable. I've spoken to others with more cam and those are being tuned. I've also spoken to several and I'm not fighting a low vac issue. 17hg seems to be a fair number. When it starts and idles the numbers seem ok just rich. So I've been pulling fuel out of the low VE table.

I did find that the Crank-AFR table is extremely rich for some reason. According to that it wants 10 to 1. Made some changes to that and I'll try that today to see if I can keep this thing from flooding.


Another thing I've noticed. After I turn the key off my fuel pump continues to run for exactly 15 seconds afterwards. Is that also controlled by the ecm as well?

 

The fuel pump is controlled by the ECM via the relay. It is also controlled by the oil pressure switch. So on a cold engine with thick oil the pump can run for some time after key-off.

If the EBL is running firmware V2.2 zero out the cranking prime pulse table:

Crank - Prime PW

RBob.

 

Yes, the firmware is V2.2. I did zero out Crank-Prime PW and Crank-AFR is 12.40 to 13.20 in the temp range I'm in for now. Just tried it and it wouldn't fire. The plugs may still be soaked from last night so I'll have to take them out again and dry off. Then I'll try and start it up again.


Double checked my TPS again and it was within range .550

 

Getting to my wits end with this thing. Gonna have to step back an try an figure out what I'm missing. I've enclosed a thumbnail of the screenshot of the crank-afr, crank- PW and choke properties.

 

From data logs look at the injector PW and CTS values during cranking. See if there is any major variance between prior and current and starts OK and floods start ups.

RBob.

 

I just took a look at 7 logs that I had that had the "cranking" stage in them..

CTS has been consistant all the way through on a cold start
aPW- is always 0

sPW- on the logs where is has started up are high 50's or low 60's then drop to below 10

on the logs where it has started they are 10:1 and lower.

What is that telling me?

 

Compare the cold start CTS among logs, along with the PW. Can also see cranking RPMs to see when the engine is actually turning over.

Also, the 400 RPM row high KPa (see log during cranking) of the VE table is used for the PW calculation.

Depending upon the CTS the high 50, low 60 msec PW seems a bit high.

Holding the go-pedal to the floor during cranking is a clear flood mode.

May need more distributor base timing. As that is used during cranking.

RBob.

 

This past season my car did exact opposite. It ran very lean on WB shortly after cranking. No CE and no code in malf display. It appears to have been the coolant temp sensor that signals to ECU. We replaced the CTS on last day of season and that appeared to fix the problem. Not sure if sensor can fail in either direction. If it sends a signal of a coolant temp -40dF it may respond with more fuel. Mine appears to have gone opposite direction.