i have a 98 z24 with a 2001 2.4 engine that I race at the local dirt track. The past couple weeks the exhaust manifold has been glowing bright red at the end of the race. Ive been racing the car all year and this is the first time this has happened. Theres no Cat converter just a muffler that still flows great. Ive put the scan tool on it and the only code that comes up is a EGR but the engine dont have one. any ideas on what it might be thanks
Are you using the 2001 iniectors in the 98?
not sure I didnt do the swap it was done when I bought the car. it just started the problem all at once
is it down on power at all? Lap times a bit slower?
if it is too rich, you may be seeing the effect of incomplete combustion.
I want to see pictures, lol... But to be serious, what they said ^^^
seems to still be running good and doesnt seem to be rich theres not much black sut where the exhaust comes out at . I wonder if its lean and what might cause it
MasterFlight wrote:is it down on power at all? Lap times a bit slower?
if it is too rich, you may be seeing the effect of incomplete combustion.
Actually, this would be the result of running too lean, not too rich. A lean mixture burns hotter than a rich one. If it's something that just started, check for a vacuum leak somewhere, such as a hose or cap that popped off. If that's no go, you may have clogged injectors, or fuel filter, or your FPR may be failing.
Edited 1 time(s). Last edited Friday, November 11, 2011 4:47 AM
The 01 engine does not have EGR, but the 98 does, therefore the computer expects it to be there.
I would agree with it running lean though.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
Hmmm....Seems odd that there is only a code for the EGR when the CAT is also missing.
I suspect that with both the CAT and the EGR missing, the computer is running the engine in an open loop, which means the computer is giving the engine a default amount of fuel, opposed to adjusting the fuel mixture to the conditions the engine is running in, as would be done in a closed loop.
Is the check engine light on?
Once the CEL comes on, the computer goes into an open loop, and missing parts of the emission system will trigger the CEL. One way of telling if the computer is staying in open loop is to look at the cooling fan. if the fan is running all the time, the engine is running in open loop. Well, on a stock system it would. If the system has been altered...well...
Any manifold will generate enough heat to make the manifold glow to some degree. How much the manifold is glowing is the question. If the whole manifold is bright red, I'd say that there is reason for concern. On the other hand, if just the first couple of inches is a dull red, I wouldn't get to excited about it.
If I was in this situation, and I didn't have any engine management experience, I'd be asking the old timers around the track if this was a reason for concern. And then I'd put the heat shield back on before I set the sucker on fire.
The reason the code for the EGR is being thrown is because the EGR is missing. The computer can not communicate with the EGR, so it sets a fault code.
So...Just what was the reasoning behind the removal of the CAT and the EGR?
The engine was designed to run with these parts, The result of removing such parts is an inefficient engine, that more than likely, has less performance. Once the computer goes into an open loop, it will no longer adjust the timing, or the air fuel mixture, which = peak power losses. , Unless, of course, the engine is fitted with a computer designed to compensate, and run properly with the removal of these parts.
A Stewart - apparently you didn't read?
The reason for the removal of the EGR is because the engine was swapped to an 01 engine which does not have EGR. The 98 engine would have it. Since the car is a 98, the 98 computer is looking for the EGR. The Cat was most likely removed because the car is being used on a track. The EGR should only operate at times of light acceleration or constant loads that you're not going to see on the track. I'd assume the car spends a lot of time going back and forth between 0% and 100% throttle. Anything over 80% would run the system without closed loop anyways. Yeah, the code is coming up, but I don't see the car trying to rely on the system much anyway.
I'm kinda wondering like mentioned above about if the thing still has the 01 injectors in it. I dunno if that would make it lean out, but it won't be right, that's for sure.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
A Stewart wrote:So...Just what was the reasoning behind the removal of the CAT and the EGR?
The engine was designed to run with these parts, The result of removing such parts is an inefficient engine, that more than likely, has less performance. Once the computer goes into an open loop, it will no longer adjust the timing, or the air fuel mixture, which = peak power losses.
Please, speak from fact, not bull@!#$.
In open loop, spark advance is still adjusted. Open loop simply means there is no primary O2 sensor input being used, so the car's fueling is based off the tables and no adjustments based on data it collects. That's not a big deal. And what do you think this guy is doing during RACING? He's at high throttle, which means he's in open loop most of the time.... closed loop is only utilized at part/low throttle and idle conditions. Furthermore, the above modifications
won't even cause the car to ignore the O2 sensor readings and thus go into open loop, so what the hell are you talking about? You don't even know...
Please, learn engine management before providing false information.
2001 Olds Alero (LD9)
636 whp / 543 ft-lb
@turboalero
[ion wrote: C2]A Stewart wrote:So...Just what was the reasoning behind the removal of the CAT and the EGR?
The engine was designed to run with these parts, The result of removing such parts is an inefficient engine, that more than likely, has less performance. Once the computer goes into an open loop, it will no longer adjust the timing, or the air fuel mixture, which = peak power losses.
Please, speak from fact, not bull@!#$.
In open loop, spark advance is still adjusted. Open loop simply means there is no primary O2 sensor input being used, so the car's fueling is based off the tables and no adjustments based on data it collects. That's not a big deal. And what do you think this guy is doing during RACING? He's at high throttle, which means he's in open loop most of the time.... closed loop is only utilized at part/low throttle and idle conditions. Furthermore, the above modifications won't even cause the car to ignore the O2 sensor readings and thus go into open loop, so what the hell are you talking about? You don't even know...
Please, learn engine management before providing false information.
Gee, I guess that the 10 years I spent doing R&D high altitude calibrations was a total waste of my time....I wonder why I was part of the team developing EFI for 2 strokes? Yeah, part of the team doing away with those inefficient carb's, just like the one in the picture on your page.
Sure sorry to hear that I now may have to call the company I worked for at the time and tell them they may need to recall all the projects I worked on, because they're all wrong.
And on top of this bad news, I guess that my test equipment must not be accurate as well. What, with the scanner showing no change in timing or injector pulse width while running in open loop. Dang Scrap on junk.
So... just let me see if I understand you. You think that an engine running with on in open loop, using an older default base map, with injectors that are in question as to whether or not they are to lean, is no big deal? How do you know that the older base map hasn't reduced the fuel flow to a dangerously lean level when coupled with the newer model injectors? Yeah, right.
Seems that your pretty quick to criticize, maybe you should think about spending a little more time trying to help by giving constructive advice, instead of trying to make yourself look better at the cost of others.
Sorry if I missed it, but I didn't see your post on what the cause of the problem was, or your advice of what to check. In fact, the only thing I saw from you, was the flame on me. My Granny had a saying, and I'm sure that it wasn't hers, but since that's where I first heard it, it hers as far as I'm concerned, and that saying was, in nicer terms, "crap or get off the pot"!
I do just fine in the area of engine management thank you, And, the only time a system should be in open loop is when first started, and @ WOT.
I'd say that we agree to disagree.
Moving on,
Have the spark plugs been checked for color? Maybe a colder plug will help.
Also, any idea of which exhaust manifold was used, or if they are the same or not. If one is more restricted than the other,and the more restricted one is installed on the engine designed for a more free flowing manifold, it could cause more back pressure than is called for. (more back pressure more heat build up.) Has the exhaust system been tested for back pressure?
The injectors themselves are of different designs, and as such should be easy to tell which are in use.
If the newer injectors are in use...replacing them with the ones from the 98 may, or may not help. Since the EGR was eliminated, there may have been other changes in the intake in the area of air flow. It maybe necessary to change back to the original intake, or...just forget about all of that crap and find the computer for the 01.lol
Just throwing out some ideas, hope you find the cause.
thanks for the ideas guys. Like I said it just started all at once. Ive raced the car over 20 times this year without a problem then all of a sudden it started the problem. The whole manifold glows bright red. I might cut the muffler off and give it a try tomorrow
Running too rich can also cause this. I have seen a perfect AFR cause a manifold to glow red.
That was on a turbo setup.
regardless need to get a wideband on the car and see whats going on.
FU Tuning
A Stewart wrote:Gee, I guess that the 10 years I spent doing R&D high altitude calibrations was a total waste of my time....
It is quite apparent that it was! Please stop while you are behind..
A Stewart wrote:Sure sorry to hear that I now may have to call the company I worked for at the time and tell them they may need to recall all the projects I worked on, because they're all wrong.
Someone's a tad insecure. This ought to be fun.
A Stewart wrote:And on top of this bad news, I guess that my test equipment must not be accurate as well. What, with the scanner showing no change in timing or injector pulse width while running in open loop. Dang Scrap on junk.
Yeah, try a real scanner next time. Guess what, the following snippet was entirely in open loop. Do you see the spark advance changing? Hurr...
A Stewart wrote:So... just let me see if I understand you. You think that an engine running with on in open loop, using an older default base map, with injectors that are in question as to whether or not they are to lean, is no big deal? How do you know that the older base map hasn't reduced the fuel flow to a dangerously lean level when coupled with the newer model injectors? Yeah, right.
Typically open loop (in our cars) causes its target AFR to drop to something decently rich under most conditions. During idle, low throttle and cruising, my tune will target from 10.5:1 - 13:1. I have no idea what you're talking about regarding "newer model injectors" though..
A Stewart wrote: Seems that your pretty quick to criticize, maybe you should think about spending a little more time trying to help by giving constructive advice, instead of trying to make yourself look better at the cost of others.
Didn't have time for that, was at work and wanted to pop on to inform everyone that removing a catalytic converter will NOT cause the vehicle to run in open loop, as you had falsely stated previously. Maybe, just maybe, you should read my post before replying. You said open loop would cause peak power losses. DEFEND THAT. When you're at high throttle, obtaining peak power, you're running in open loop... thus your statement is invalid. If you had read my post instead of focusing all your attention on building your ego back up in an attempt to prove to me that you're such a spectacular source of modern engine management knowledge, maybe you wouldn't have wasted so much of your time making yourself look like a fool.
A Stewart wrote:Sorry if I missed it, but I didn't see your post on what the cause of the problem was, or your advice of what to check. In fact, the only thing I saw from you, was the flame on me.
As I said above, I only signed in to clear up misinformation that you had posted regarding open loop: it's causes and effects on various engine management items. Try again.
A Stewart wrote:I do just fine in the area of engine management thank you, And, the only time a system should be in open loop is when first started, and @ WOT.
I agree with this statement, as would anyone who is knowledgeable in the workings of any modern electronically controlled engine. So why is it that you claimed it would cause so much concern to someone who is RACING? His car doesn't use closed loop at high throttle. We don't have factory equipped widebands, here.
Also, the fan doesn't come on just because the car is in open loop.. where exactly are you getting this information from? It can't be experience..
2001 Olds Alero (LD9)
636 whp / 543 ft-lb
@turboalero
Mr. Quick wrote:MasterFlight wrote:is it down on power at all? Lap times a bit slower?
if it is too rich, you may be seeing the effect of incomplete combustion.
Actually, this would be the result of running too lean, not too rich. A lean mixture burns hotter than a rich one. If it's something that just started, check for a vacuum leak somewhere, such as a hose or cap that popped off. If that's no go, you may have clogged injectors, or fuel filter, or your FPR may be failing.
I stand corrected....to a degree. It is true that a lean mixture may not burn completely in the cylinder but finish burning in the exhaust.
For F/A ratios, the common tool now is the O2 sensor. The old fashioned one is the EGT.
After many years of flying for a living including thousands of times setting mixtures and watching turbo's glow red at night have taught me that if there's too much fuel it can increase the exhaust heat, but downstream of the egt.
When setting the egt, the temp would peak fairly close to stoich, but increase another 25-50 degrees as it becomes lean; then the engines would begin to run rough and the egt would start dropping. We normally set them for 25 degrees rich side of peak, although they were approved to run on the lean side to a degree.
This was on the Piper Navajo with Lycoming TIO 540 J2BD engines. 540 cubes, 350 take off HP, max continuous HP of 75-80% if I remember right. Take off power was limited to 5 minutes at 2700rpm and 41 inches of MAP. Climb power was 31 inches of MAP at 2500 rpm. Cruise was 29" MAP at 2200 rpm. They'd go about 1000 hours and puke the turbo (a big honker). Put on a new turbo, and they'd usually go 2000 hours without too much trouble.
One thing not mentioned was that this may be an indication of late ignition timing. With late spark, the combustion is not complete by the time the exhaust valve opens and the continuing burn can get the exhaust manifold a really pretty red.
dennis
A Stewart wrote:[ion wrote: C2]A Stewart wrote:So...Just what was the reasoning behind the removal of the CAT and the EGR?
The engine was designed to run with these parts, The result of removing such parts is an inefficient engine, that more than likely, has less performance. Once the computer goes into an open loop, it will no longer adjust the timing, or the air fuel mixture, which = peak power losses.
Please, speak from fact, not bull@!#$.
In open loop, spark advance is still adjusted. Open loop simply means there is no primary O2 sensor input being used, so the car's fueling is based off the tables and no adjustments based on data it collects. That's not a big deal. And what do you think this guy is doing during RACING? He's at high throttle, which means he's in open loop most of the time.... closed loop is only utilized at part/low throttle and idle conditions. Furthermore, the above modifications won't even cause the car to ignore the O2 sensor readings and thus go into open loop, so what the hell are you talking about? You don't even know...
Please, learn engine management before providing false information.
Gee, I guess that the 10 years I spent doing R&D high altitude calibrations was a total waste of my time....I wonder why I was part of the team developing EFI for 2 strokes? Yeah, part of the team doing away with those inefficient carb's, just like the one in the picture on your page.
Sure sorry to hear that I now may have to call the company I worked for at the time and tell them they may need to recall all the projects I worked on, because they're all wrong.
And on top of this bad news, I guess that my test equipment must not be accurate as well. What, with the scanner showing no change in timing or injector pulse width while running in open loop. Dang Scrap on junk.
So... just let me see if I understand you. You think that an engine running with on in open loop, using an older default base map, with injectors that are in question as to whether or not they are to lean, is no big deal? How do you know that the older base map hasn't reduced the fuel flow to a dangerously lean level when coupled with the newer model injectors? Yeah, right.
Seems that your pretty quick to criticize, maybe you should think about spending a little more time trying to help by giving constructive advice, instead of trying to make yourself look better at the cost of others.
Sorry if I missed it, but I didn't see your post on what the cause of the problem was, or your advice of what to check. In fact, the only thing I saw from you, was the flame on me. My Granny had a saying, and I'm sure that it wasn't hers, but since that's where I first heard it, it hers as far as I'm concerned, and that saying was, in nicer terms, "crap or get off the pot"!
I do just fine in the area of engine management thank you, And, the only time a system should be in open loop is when first started, and @ WOT.
I'd say that we agree to disagree.
.
Hey look.... another one!
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
^Lol.
Its either going to be an afr issue or a too retarded timing issue. When we were trying to sort out the tune on the racecar last winter we were making the header glow at idle. I guess -14* or spark advance (lol - advance) to try and make it idle down with a monster vacuum leak (never run a rapid prototyped intake manifold) makes for some high EGT's. Of course that engine is also famous for running super hot and yamaha actually cools the header with snow on the sled it comes from.
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I'd look for a major intake leak, I had a fiero that did the same thing when I rebuilt it. I had a cracked intake that was causing it to run lean and cause the exhaust manifold to glow red. Since it just started happening I'd look for leaks first.
