My engine is still glowing the headers. I can let it idle into closed loop, let it sit there for a few minutes and no problems. I brought it up to about 1500 rpm and the headers started glowing... I was at 32* Spark Advance, and about 48 Kpa MAP. My BLM's were 108. Any ideas on what needs to be changed in the EEPROM to correct this? I havent tested going off-idle in open loop yet.

 

you are too rich and/or the timing is too retarded. IF you don't have any mech problems then you'll need a custom chip...ve tables/idle speed/timing needs set. You might want to check your base timing...

 

Is it possible that he has too much injector? (After burn in headers)?

 

I've pretty much helped him through-out the whole project.

He has:

406 ci
30 lb. SVO's
Holley Stealth-ram
Aluminum 200cc Pro-toplines
~10.5 : 1 compression
cam - .510 / .540 229/245 @.050 112 LSA

(I dont like the cam, for the record) Sorry, Scott !

His motor only pulls like 10 in. merc vaccum (he just installed a vaccum pump for help with brakes)

Fuel pressure is set to ~38 - 39 PSI at idle (850 rpm's or so)

Him and I have burned several chips for his motor allready.

We set base mech. timing to 8* and set base timing constant in PROM to 8* as well. We also changed inj. constant to 30 lb's in PROM, upped the Main spark table a few degree's across the whole table, Zero's out PE spark advance table, changed PROM cylinder volume to 406ci, changed CCP % to 0 so it's not stuck in cell 4 anymore, disabled EGR, AIR, and Vats. Thats about it I think in his current PROM.

It's idleing in cell 9 now.

Scott and I are stumped! Any advice would be appreciated!

Did I miss anything Scott?

 

What is going on is that unburned fuel is going through the exhaust. If there was no exhaust you would see something like gowing flameballs coming from the heads. It is a common problem. It's not enough timing causing the fuel to ignite on it's way out the chamber and/or too much fuel that's still burning when it exits the heads( too much fuel for ignition to ignite). If he has aftermarket injectors and a stock chip, that could cause it....

 

email me the bin

 

The chip is not stock, read my prior post.

Timing is advanced.

He has a new heated 3 wire o2 installed.

at part throttle (just rasing rpm's to 1,500), it;s glowing headers.

You guys think that switching to 24 lb. injectors would help?

Or maybe raising injector constant to 33 - 35 might help?

 

He said that BLM was 108....
Try leaning it first.
I had sim. probs with my car when I had to much overlap, but that does not seem to be the case with his cam.
I had tried switching back to my 22 lb injectors just to test and same thing....
But for now try toi just scale lower VE 10% or so untile BLMS get close and see what happens.
Also as far as timing, don't look at main spark advance table for idle - look at closed throttle spark advance table.

 

Cool, we will try that!

So, you think it's that crappy cam with too much exhaust duration that's the culprit?

 

No, Not really.
That cam does not look like it should give any problems.
Most likely its the fueling.

 

Damn you Mike, my cam is da shizzle! I saw the Closed Throttle Spark Advance table last night, the numbers are still stock, so they could be bumped up a few across the board. I'll try scaling down the VE values 10% from 1000 RPM to 1500 RPM to see what I get in terms of BLM. My BLM cell boundries also need some work, because this engine definately doesnt match the stock ones! Thanks for the help guys. I'll be back with more info later tonight (hopefully)

Scott

 

Try to scale them from 800 - 3000 rpm's!

We'll fine tune them with VEMaster later, when we get the damn headers to quit glowing!

 

11sOrBust and 87_TA are on the money.

I'm going to play Devil's Advocate here so please excuse my harshness. What's the problem? The BLM is at 108 which indicates that it is rich so just lean out the VE Table in the RPM/kPa that it is idling. Easy. Too much injector? Huh? No such thing as too much injector when using 30lb SVOs. Set the fuel pressure to 43psi (no vacuum), adjust the cylinder volume, adjust the injector constant to 33lb, and then attack the VE tables in order to bring the part throttle fueling into line.

Tim

 

We did adjust the cylinder volume and inj. constant.

Why set inj. to 33 lbs ? The 30 lb SVO's are rated at 30 lbs @ 39.5 PSI (we set fuel pressure to ~39.5 PSI).

I thought you guys always said to keep the fuel inj. constant to match actual fuel injector and to NOT raise constant to lean motor?

 

He's saying to set the FP to 43 to make the 30# SVO's think they are 33# injectors, so setting the consant to 33# would be correct in that situation. Right? But even so, why would bumping up FP be necessary, when I'm already running rich? That'd just mean I'd have to scale the VE table even lower to get it to run "right", wouldnt it?

 

I said what I said regarding fuel pressure and the injector constant to ensure that you guys had matched the injector constant to what the injectors are really flowing. A 33lb constant with ~43psi will be equal to what those injectors flow. OR, use the 30lb constant and put the pressure down to 39psi. Whatever - as long as the rating in the PROM equals what they are truly flowing.

Now get to work on those VE tables. It's quite easy to fix that 108 BLM

Tim

 

We will be leaning out VE.

So ya think leaning out VE will fix glowing headers? I guess we'll find out this weekend!

 

Im going to differ a bit with every one else and say its soley on the ignition side. Even with my engine running rich enough to contaminate the oil and blow lots of smoke the headers never glowed, in fact, i beleive that adding all that extra fuel will just cool the combustion temps. The only thing that seems to cause the glowing headers is either too little time, or too cool of a spark, which in turn causes the mixture to burn late and not be fully done combusting when it exits the cylinder. As long as the spark ignites the gas soon enough, the mixture will jsut burn untill most, if not all of the oxygen is burned. Even if theres excess fuel, it wont keep burning because all the oxygen has been consumed. I guess if you ahve AIR or an exaust leak the mixture could re-ignite on its way out and cause it to glow but as long as its working properly, the diverter valve should keep the fresh out out of the headers. My expierience is that the only things that seem to cause the headers to glow are either the timing being too late or an ignition problem/misfire causing the mixture not to fully ignite. I suppose its possible to totally swamp the spark plugs with fuel and cause a misfire but i have yet to run it that rich.

 

He's running the cold plugs that Pro-Topline recommended (C59C).

 

I guess the plugs fouling could cause it, jsut my opinion, though. I managed to melt alot of stuff when one of my sparkplug wires completly burned to a crisp inside and the loss of resistance damaged my coil. After that, my headers started to glow because there wasnt enough spark enegy to ignite the fuel.

 

Too cold a plug can cause a missfire, its deffinetly possible to run rich enough to blow out spark as well.

Fix one problem at a time! Get the fuel within ECMs control and then go from there. It takes 20 seconds to do, scale the VE ,burn the prom and stick it in .
If that does not help we will work on other things.

If you want more to worry about - a new engine thats rings have not seated yet will blow sometimes enough oil into header to cause the same problem.

 

Notice everything I mentioned has to do with fixing 108 BLMs ... not fixing the glowing headers.

FWIW - at one point in my life I had glowing headers. I later discovered that my timing was 20d off I had installed a new Fluidampr and was using the wrong side of the balancer for timing. That was a long time ago so no jokes

I also think that it is more of a timing issue and agree pretty much with what dimented said.

Tim

 

Well, I hope scaling down the VE values will not only bring the BLM's closer to 128, but hopefully it will stop the headers from glowing as well!

It's kinda hard to monitor the BLM's when you have to shut the car off overy 2 minutes cause the damn headers are glowing!


By the way, we made the same mistake reading his Fluidamper too! But yes, we are at 8* mech. advance on the distrib!

 

1bad91z, how much timing do you ahve called for in the bin? I found when i first got my thirdgen that going wild and adding in lots of base timing can cause the engine to misfire at mid map values because the outragous base time plus what the ecm called for was more then the maximum 45 degrees physically allowed for by the distributer for each cylinder. Didnt really care too much because it was on my 200k+ 305 but it taught me a quick lession in the geometry of distributers.

 

This is my Main Spark Advance table. It is tamed down a bit from Mikes aggressive timing, I wanted to start a little lower, rather than start with too much. My base timing matches the constant in the ECM, 8*.

 

Did the headers glow with the stock timing? If you are not sure then try the stock tables.

 

IIRC i dont think the ecm allowes much over 40 degrees of advance so if you have much over that limit and you havnt set the upper limit on advance the ecm will jsut default to the max limit. It also makes sense not to go much over 40 degrees anyway since past that there is the risk of cross arcing to the next terminal.

 

heh.. just for fun, heres the timing table from my 88 tbi. Downright sissy in comparison to the timing on every one elses hi-po setups. In my not so professional opinion id definatly get any timing issues worked out before you lean out the fuel since it may detonate when the mixture gets closer to stoich.

 

tbi is different. You'll have to add your spark bias to your main spark to compare...

 

the spark bias is already added in TC is WYSIWYG

 

Right now his car is soo rich the ecm can not even compensate anymore for it. The risk your at running that rich far out weighs the risk of detonation (which you have a knock sensor for.
@ 55 kpa and 1500 rpm he is showing 28-33* timing - not that risky at all.

 

Your right in that respect. If hes rich enough to cause a protracted burn that carries over into the headers that should be addressed asap since its possibly washing the rings down.

 

on a side note, though. The whole timing thing is different between the tbi and tpi. It seems like the tpi is tolerant of alot more timing then can be run with tbi, esp. one with cast iron heads like mine. I tried adding alot of timing and when i got my fuel to stoich i got alot of p/t detonation.

 

I appreciate all the help guys. I didnt get a chance to test out the new BIN file(s) I've made. Here are the changes I made to each bin:

Hopefully with the changes in BIN 3 the car will idle better (since it wont be trying to idle down to 725 or 750), and with the BLM RPM Cell Boundries massaged a bit to "match" the engine. And with the leaned out VE, hopefully I see higher than 108 BLM's at idle and 1500!

 

Its a good start and I know I said 10% but after doing the math
108 is 18% from 128. But little moves are always better.
So do not be surprised if you have to drop it alot more.
Also you should drop all sorrounding areas as well.
I would drop the whole lower VE from 80 KPA - 20 and 2000 - 400 RPM BY 10 % .
You are soo rich right now because the new cam does not pull near the vacuum the stock did at low RPM. So your ECM always thinks you are under more of a load than you really are anywhere below the cams effecienct range.

 

87t/a, What cell do you idle in?
On a side note, I think my engine will be ready to start today.

 

sounds like you just need to capture your map vs rpm aldl readings and lean out those areas. Don't go into the ve tables assuming where you need to adjust. Confirm the map and rpm by looking at your log data.

Looks like you are going in the right direction. My headers use to glow. It scared the sheet out of me. So I learnd that it's usually caused by not enough timing and/or too much fuel.(in turn will foul the plugs,etc). I think we are all on the same page here. But I wanted to make that clear for future searches. It wasn't too easy for me to figure it out a couple of years ago.

 

I did compare my logged data to make my modifications. Guessing will get ya nowhere fast.

 

Well That depends on coolant temp..
If coolant temp is below 120 it idles in cell 4 - if 130 - 150 range its cell 9 - and above 150 is cell 4 again.

Its about time that thing runs! How can you take it?
I had to take mine out in the winter icy snow today to get kerosene - well did not have to but

As far as the guessing, I hope that was not replied to my post but you are right..
The reason I said drop all below 2000 is because: 1st you will find yourself dropping them anyways beacuse of the cam, 2nd because if your cam has a rough idle its going to touch in deffernt map areas and you will find your self in the same boat..
A VE table is usually pretty fluid looking and smooth , so if you need to drom 1500 rpm @ 50 kpa 15% all areas around are probably going to be rich as well.
Thats why I suggested that as a start point from a stock bin stand point. I'm sure you could agree 11's.

 

so are the glowing headers fixed yet??

 

I wasnt able to make it out there last night (car is at my parents house), and I'm not going to make it out there tonight, so maybe Wednesday...

 

He doesnt want to miss his TV shows tonight!

 

Well, I dont have much info, as I havent had a chance to study the logs that I got on Wednesday, but I did notice something. The headers started glowing while still in open loop this time. I noticed that timing was being taken out as the engine warmed up. When I started it, I was at about 19-20* Spark Advance, and when I noticed the headers start glowing (~100-120 seconds into the scan), I was around 15-17* timing. I was still pig rich at idle in open loop, but when I entered closed loop on the second scan, my BLM's were around 110-112, not sure on the timing there, headers started to glow there too. This is all @ idle w/ 90% of stock VE values. I'm thinking dropping it down to 85% of stock, and bumping up the timing? Idea's, Suggestion's?

 

Hmmm... thats unusual that the timing dropped that low given what you have in your table. What rpm whas the engine at when they started to glow? Now that i have the spark advance in my aldl stream I noticed that the commanded spark from my ecm is around 24 degrees or so at a fast (800 rpm) idle and around 28-32 degrees at cruise. The rather low advance combined with a rich mixture is probably your problem, and it also may contribute to the low blms. The question is, why is teh commanded spark so much less then what you have in the tables? Just out of curiosity, what is the advance at the balancer?

 

I set his mechanicle advance on the distrib. to 8* and his contant in his PROM is also set to 8*.

 

It was idling at 1000 rpm at the time, which is also a bit higher than what I expected. Maybe because it was 33*F outside? I'll check the Idle RPM vs Coolant Temp table. I'm not sure what my advance was at the balancers, I didnt have the timing light out. I don think the main spark advance table is used for open loop idle either, which could be a problem as well.

Scott

 

how is the advance calculated for the tpis at cold idle? I know for the tbis its jsut the main SA + any additional SA thats added in on cold start.

 

Well there are two other tables that contribute::
-The base adv. correction vs coolant/load.
-And your idle timing is taken from the closed tps vs coolant.

Some things you want to try still - yes take out more fuel!
your goal is to reach 128 BLM , but now you are getting in the ball park. You are going to notice that everywhere below 2k and 70 kpa you will be rich over stock from that cam - expect to drop that whole lower ve from 2k and 70kpa and below atleast 15% FROM STOCK.
Now you are @ 112, excellent! now you have somewhere to work from, drop the VE by 13 more % in the areas you have seen that 112 that should get you real close on fuel. Well maybe drop the whole table 5% and drop the area by 13%

For the headers, 1) you may want to varify timing with a light at the balancer vs. scanner
2) you may want to try physically advancing the timing 5-10 degrees while idleing just to see if headers stop glowing for a test. If that does not work then try to retard it.
A hand held pyrometer works great trying things and watching the results.
3) If you find that moving the timing cures something then you will want to varify TDC vs. balancer marking.

Where do the headers glow?
Right off the head, or at the collector? just one side or both?

 

Mech timing is set to 8* advanced (YES, it was verified with a timing light).

The glow is close to the heads on both headers (right as the primaries bend downwards).

Scott -

is it possible that your balancer was installed " a little off " ?
Is your crank keyed or are there several bolts that just hold it in place?

 

So the SD tpi ecms actually have seperate tables for spark when the throttle is closed that are based on rpm and coolant temp. Wish i had that.