Help! Lean Condition, Need Help

[Crosschkm]

;helpI am having some fine tuning done and getting ready for the season. I have the car at Haibeck Automotive ( very competent shop) they specialize in ZR1's and work on a couple of Callaways. We were getting ready to increase :Jboost :Jand made some baseline observations prior to any increase and found this problem:W. The car is very solid other than this detonation problem.
The detonation occurs when I make WOT runs in third gear from 2000 to 5000 rpm. The ECM scan data shows the knocking beginning at 3000 rpm peaking at 3500 rpm and tapering off to sharply after 4500 rpm. 10 to
15 strong knocks occur with a peak retard of -12 degrees at 3500 rpm.
At the same time my wide band oxygen sensor records the following:
RPM 2000 2500 3000 3500 4000 4500 5000
AFR 13.0 13.3 13.6 14.9 13.8 13.3 12.1
Knocks 0 0 1 2 6 5 1 Total knocks for the run = 15
Boost is 52" hg. absolute.
Fuel pressure is 55 psi from 3000 to 5000 rpm.
The L98 fuel injectors were replaced with GM parts about 1000 miles ago. The electrical resistance is 17.5 +/- .1 ohm for the set hot.
The Callaway injectors are 2.3 ohms cold and 2.7 ohms hot which is said to be normal by Callaway technical support. They flow 83 lbs./hr. We cleaned them.
The electrical drive for the injectors is 12 to .5 volts at 10 ms.
We drained the fuel and filled the tank with Shell 93 octane.
The car does have the Callaway chip in it, but could it have been programed wrong from the start?
I wonder what the procedure is to add fuel to the Callaway Microfueler from 3000 to 4000 rpm?

We have contacted :BOWCallaway and they helped with a couple of issues, but they have not called us back reference this problem. I think they are busy, however does anyone else have an idea what could be causing this problem while I wait for a call back?

 

[c4c5specialist]

HI there,
If you look at your AF ratio, that give you the key, your too lean.
That being said, you need to get it into the 11.4 - 12.5 AFR.
MAF sensor a bit off, maybe contaminated??
O2 sensor, unless you are at WOT, because at WOT the sensors are defaulted.
Allthebest, c4c5

 

[Crosschkm]

Thnaks for your help, but the detonation is occuring at WOT. Any other Ideas would help.

Cross

 

[c4c5specialist]

HI there,
Well, I personally would start with the MAF sensor readings.
From idle, at about .5 volts up to 4500 rpm/4.2 volts.
Make sure that your increase in voltage from the MAF sensor correlates to the increase in RPM.
Allthebest, c4c5

 

[Hib Halverson]

First, let me caution you--you have serious detonation at or near peak torque and, with -12 knock retard, you may be nearing the point where the system cannot dial in enough KR to protect the engine. Be careul.

The detonation occurs when I make WOT runs in third gear from 2000 to 5000 rpm. The ECM scan data shows the knocking beginning at 3000 rpm peaking at 3500 rpm and tapering off to sharply after 4500 rpm. 10 to
15 strong knocks occur with a peak retard of -12 degrees at 3500 rpm.
At the same time my wide band oxygen sensor records the following:
RPM 2000 2500 3000 3500 4000 4500 5000
AFR 13.0 13.3 13.6 14.9 13.8 13.3 12.1
Knocks 0 0 1 2 6 5 1 Total knocks for the run = 15

Lean AFR (way lean[/]at part throttle!!) is obviously, the cause of your detonation. First, you need to troubleshoot the fuel system to see if, inspite of the 55 psi, there's a restriction which is causing reduced fuel flow.

If the fuel system checks out, then you need to get more fuel into the engine somehow...either more pressure and volume or injectors which can flow more fuel.

Lastly, don't be surprised if getting "tech support" from Callaway on a 20 year old car is difficult.

Good luck!

 

[SurfnSun]

Lastly, don't be surprised if getting "tech support" from Callaway on a 20 year old car is difficult.

Good luck!

:eyerole Is that statement based on fact or personal experience? Me....Being someone that actually owned a b2k car I found the support to be quite good.

Anyway...back to the facts. Id say its kinda hard to diagnose something like this over the phone. But being someone who battled thru the exact same situation when I first got my TT car, I fully understand the frustrations and challenges.

Cross, I emailed you my phone number.

 

[89onlyZ51]

Since you have a '90, you don't have a MAF (it would be pegged anyway if you did). As Surf has probably already told you, your problem is probably related to the Callaway Mircofueler system (drives the extra 2 injectors). Unfortunately, it's not adjustable for specific RPM ranges (just fuel x rpm and fuel x boost overall). Any mods will throw the microfueler calibration off - is your car 100% stock? It doesn't looks like you microfueler is dead since you'd be way leaner than your numbers above.

 

[Crosschkm]

Since you have a '90, you don't have a MAF (it would be pegged anyway if you did). As Surf has probably already told you, your problem is probably related to the Callaway Mircofueler system (drives the extra 2 injectors). Unfortunately, it's not adjustable for specific RPM ranges (just fuel x rpm and fuel x boost overall). Any mods will throw the microfueler calibration off - is your car 100% stock? It doesn't looks like you microfueler is dead since you'd be way leaner than your numbers above.

I was trying to be nice, I know I don't have a MAF. Its not the Microfueler system, it is firing correctly. After reviewing this problem with Surf and a few others I am leaning torward this being a computer chip problem. We have added fuel to the map and reduced the problem. Now we are going to remove some spark and try to enrich the Microfueler with the potienometers. I will update.

 

[Hib Halverson]

:eyerole Is that statement based on fact or personal experience?
(snip)

Actually, both
1) The person who posted (presumably the owner of the car) said:

We have contacted :BOWCallaway and they helped with a couple of issues, but they have not called us back reference this problem. I think they are busy, however does anyone else have an idea what could be causing this problem while I wait for a call back?

I have no reason to think he's lying, so the statement seems to be fact, ie: he's having trouble getting the level of support he needs.

2) In my 25 years experience working in the automotive press, I've found it unusual when an owner of a 20 or so year-old product can obtain support of the same level which someone who owns a recently-produced product by the same business can get.

Now...I never said that Callaway "will not" or "refuses" to support a '90 Callaway, I just suggested that one not be surprised if otaining support for a 20 year old car might be difficult.

"Difficult" could be a variety of reasons.
1) Callaway may prioritize support to the newest products first.
2) On some days (or every day) there might not be the knowlege base available at Callaway for a 20 year old product.
3) The aforementioned difficulty with DvI (diagnosis via Internet).

So, "SurfnSun"....I stand by that statement and, further, I don't need to own a Callway TwinTurbo to make it.

As for the issue at hand...

While I agree this could be a calibration problem, what I don't understand is if, the problem occured on baseline chassis dyno runs and you're using the cal that came in the car (which was presumably ok, before) why, all of a sudden, as the engine gone lean near peak torque? I'd tend to think this is not a cal problem...unless the existing cal has never been right.

Has it always had the detonation problem, or did the issue recently develop?

 

[*89x2*]

Cutting through the bull...

Wow, this thread has gone downhill... :eyerole


Callaway Cars, backed by Reeves Callaway's statement in 2002, pledged continued support for the earlier cars.

There is ALWAYS someone who can take a call (during business hours) to help resolve any issue. Priority is not a concern. Proper support is paramount. :cool

There is LOTS of knowledge available, every day. Some employees have "been there, done that," and were builders of B2Ks in the day :cool

Parts are available, on the shelf, NOW. If it isn't available, parts have been sourced or in extreme cases, fabricated.:cool

Rebuild services are available for other specific components. :cool

In fact, last I saw, there were four Callaway Twin Turbo Corvettes at the shop for various service/maintenance matters. :cool

The only point I see with any relevance, was related to diagnosing issues over the internet. It does not matter what vehicle is discussed, as a rule, the internet diagnosis method generally does not produce (satisfactory) results.

 

[89onlyZ51]

I was trying to be nice, I know I don't have a MAF. Its not the Microfueler system, it is firing correctly. After reviewing this problem with Surf and a few others I am leaning torward this being a computer chip problem. We have added fuel to the map and reduced the problem. Now we are going to remove some spark and try to enrich the Microfueler with the potienometers. I will update.

My finger's still pointing to the microfueler or it's vac feed, and here's why. The calibration in the stock computer's prom will not change by itself. When the prom goes, it will usually lose a few bits, and this will throw off the checksum, which will put the car in limp mode and throw error codes. Since you don't mention error codes, I can't see how the base prom calibration is the problem (unless you're not using the cal that Callaway originally supplied or have made other mods to the engine).

Also, in your speed density system, the base cal only has fuel and spark entries up to 100kpa (0 vacuum) and has no provisions for boost. This means the stock computer will supply the same fuel from zero vacuum all the way throughout whatever boost range at a given rpm (not good). This is where the microfueler comes into play by adding the extra fuel needed while in boost and why adding fuel in the base table may only move and not solve your problem.

Since your problems only appear while in boost and you don't have problems while not in boost, I still think you have a microfueler tuning problem.

Just curious, how did you test to ensure that the microfueler is putting out the correct amount of fuel for a given boost/rpm value? Not trying to be a pain here; I just think the approach you're following will move but not solve the problem your seeing. pm me if you'd like to chat on the phone as I have a few other ideas/suggestions, too.

Tom

 

[Crosschkm]

Wow, this thread has gone downhill... :eyerole


Callaway Cars, backed by Reeves Callaway's statement in 2002, pledged continued support for the earlier cars.

There is ALWAYS someone who can take a call (during business hours) to help resolve any issue. Priority is not a concern. Proper support is paramount. :cool

There is LOTS of knowledge available, every day. Some employees have "been there, done that," and were builders of B2Ks in the day :cool

Parts are available, on the shelf, NOW. If it isn't available, parts have been sourced or in extreme cases, fabricated.:cool

Rebuild services are available for other specific components. :cool

In fact, last I saw, there were four Callaway Twin Turbo Corvettes at the shop for various service/maintenance matters. :cool

The only point I see with any relevance, was related to diagnosing issues over the internet. It does not matter what vehicle is discussed, as a rule, the internet diagnosis method generally does not produce (satisfactory) results.

All right everyone lets simmer down.

Calaway Support- Callaway has always been supportive, I think the rest of the auto industry could use them as an example. How many people would even think about calling for information on a 20 year old car and expect to get it. The people at Callaway are always very nice and respectful. I admire the way they protect their clients past and present and protect their product (how many cars do you see with Callaway markings that are not Callaways).The person we would like to talk to is Mike Zoner, but I do feel they are very busy at this time, if I thought they were blowing me off I would state that. I have nothing but the ut-most respect of Reeves and his people.

Cal Problem- After speaking to several members who have dyno tuned their Callaway cars with the wide band o2 and examined the issues. I now know of 4 cars with the exact same lean problems in the exact same area. Some fixes were completed with a cal change, and some with mechanical modified fuel delivery. But again the lean areas were the virtually same on all the cars. I don't know how long my car has experienced the issue. I could be wrong but I don't think that Callaway customized :bangevery chip for every car. My chip is hand written 1990, six speed, coupe. This leads me to belive that Callaway probably made a base chip for those cars, and base chips for automatics with different gears. It would not suprise me that some cars may be lean. As we know there are a lot of variables that can creep in. I am sure we are all aware of the fact that if you were to buy 10 identical in option vettes (or other cars). 2 will be very fast, 3 will be slower than expected, and 5 will operate in average expected way. This is a FACT. A friend of mine use to own a dyno shop in Joliet Illinois and we would see this on Dyno days even with C5 and Zo6's that were almost identical in mileage and options. The LT5 guys know this and that is a perfect car to use as an example because after 90 the only option difference was 1 targa or 2. We would post our DYno numbers and there were head scratching differences. The greatest difference we observed in cars that were very simular were on guess what? TURBO Cars. We would see this when the clubs would due a Dyno Day. Weather it was pristeen never driven untouched Grand Nationals, or the import guys the turbo car difference was huge.

I purchased my car 6 years ago and never had any problems (never heard a knock). I still dont ever hear a knock or detonation. This car was owned by one of the Real VP's at GM and was a garage queen and babied until I got it. So it would not suprise me that its been lean since it came out of the dealer. A lot of the Callaways I have seen are garaged and not driven hard so it would not suprise me if there are others out there lean that have not failed.The only way we became aware of the problem was by making some base runs in preperation of increasing the boost.
I have the best guy (Mark Haibeck) in the Chicago land area working on the issue, and the fuel system is soild, everyting is flowing what it should, and activating when it should. The only change to the fuel system other than Cal Map is to enrich the Micro Fueler. I have a 4 potineometer Micro Fueler, does anyone have a break down of this model. I have a break down of one with three.

I was at Bloomington Gold when Reeves told us how to make these cars really run, and that his motors can take alot more boost.


I thank everyone for there help, ideas, and tips. But lets SIMMER down.

 

[Crosschkm]

Problem Fixed

All right everyone lets simmer down.

Calaway Support- Callaway has always been supportive, I think the rest of the auto industry could use them as an example. How many people would even think about calling for information on a 20 year old car and expect to get it. The people at Callaway are always very nice and respectful. I admire the way they protect their clients past and present and protect their product (how many cars do you see with Callaway markings that are not Callaways).The person we would like to talk to is Mike Zoner, but I do feel they are very busy at this time, if I thought they were blowing me off I would state that. I have nothing but the ut-most respect of Reeves and his people.

Cal Problem- After speaking to several members who have dyno tuned their Callaway cars with the wide band o2 and examined the issues. I now know of 4 cars with the exact same lean problems in the exact same area. Some fixes were completed with a cal change, and some with mechanical modified fuel delivery. But again the lean areas were the virtually same on all the cars. I don't know how long my car has experienced the issue. I could be wrong but I don't think that Callaway customized :bangevery chip for every car. My chip is hand written 1990, six speed, coupe. This leads me to belive that Callaway probably made a base chip for those cars, and base chips for automatics with different gears. It would not suprise me that some cars may be lean. As we know there are a lot of variables that can creep in. I am sure we are all aware of the fact that if you were to buy 10 identical in option vettes (or other cars). 2 will be very fast, 3 will be slower than expected, and 5 will operate in average expected way. This is a FACT. A friend of mine use to own a dyno shop in Joliet Illinois and we would see this on Dyno days even with C5 and Zo6's that were almost identical in mileage and options. The LT5 guys know this and that is a perfect car to use as an example because after 90 the only option difference was 1 targa or 2. We would post our DYno numbers and there were head scratching differences. The greatest difference we observed in cars that were very simular were on guess what? TURBO Cars. We would see this when the clubs would due a Dyno Day. Weather it was pristeen never driven untouched Grand Nationals, or the import guys the turbo car difference was huge.

I purchased my car 6 years ago and never had any problems (never heard a knock). I still dont ever hear a knock or detonation. This car was owned by one of the Real VP's at GM and was a garage queen and babied until I got it. So it would not suprise me that its been lean since it came out of the dealer. A lot of the Callaways I have seen are garaged and not driven hard so it would not suprise me if there are others out there lean that have not failed.The only way we became aware of the problem was by making some base runs in preperation of increasing the boost.
I have the best guy (Mark Haibeck) in the Chicago land area working on the issue, and the fuel system is soild, everyting is flowing what it should, and activating when it should. The only change to the fuel system other than Cal Map is to enrich the Micro Fueler. I have a 4 potineometer Micro Fueler, does anyone have a break down of this model. I have a break down of one with three.

I was at Bloomington Gold when Reeves told us how to make these cars really run, and that his motors can take alot more boost.


I thank everyone for there help, ideas, and tips. But lets SIMMER down.

Thanks to everyone with their help. This is how the problem was fixed.

Added as much fuel as possible to the engine control system in the 3000 to 4000 rpm area. Reduced the timing -4 degrees ( when it would start knocking the car would reduce itself -12 degrees).
Originally the Microfueler was set with its enrichment range with the Fuel verses RPM control set at 90%. It was changed to 100% and a small amount of fuel was added.
The Fuel verses Boost setting was at 60%. It is now 80% and it added a small amount of fuel. It still has some knocks.
Then set the control at 100% and added as much fuel as possible in the engine control system.
The fueling is now correct and safe. It's about 12.1 now when on boost. There is an occasional small knock which is to be expected with a turbo engine. Keep in mind I am still runing 93 shell. Now its time for some good gas and screw turning.

So I feel nothing was broke on the car, just never fine tuned. It took a skilled mechaninc (Mark Haibeck) at a great shop (Haibeck Automotive Performance) to make these adjustments. If you ever need work on your Callaway or ZR1 (which is his specialty) he is located in the suburbs of Chicago call him or visit him at www.zr1specialist.com .

A special thanks to Surf for his help off line and Hib as well. Callaway was not a great help this time, but it is a very busy time of year for them (i inderstand) and they are usually great. Their sales staff was always nice and did try to help but we could not get in touch with the people we wanted. That being said I don't know of any other company that would be as helpfull and supportive with a 20 year old car, that they are not working on. Callaway and his company are a step above, and for that reason I would buy another Callaway in a spilt second.

So keep the PSI HIGH and thanks to all again