Shunting in 4th & 5th gear at low RPMs

My 2002 GT did that from day one till I traded it in. The dealer didn't have a clue as to what was causing it. I just learned to live with it.

It seems that a lot of us have this problem. Some people get it at stock, others get it after even small mods.

The reason that the problem "seems" to go away if you go to a lower gear is the fact that the throttle plate is opened further and more air is going in at higher RPMs. This tends to "dampen" the effect of the opening EGR valve. At a lower rpm, the EGR opening up is a relative bigger change to the engine than when the rpms are higher. My guess is that Ford and tuners have not yet taken this problem serious enough to fix it. I will try to explain both scenarios.

Stock Ford: Some cars have the hitching problems, while others do not. Every Ford off of the assembly line gets the exact "same" parts and chip. Ford knows that no two cars will ever be "exactly" the same, as there are acceptable "tolerances" for each part. For those that get a car that have parts with tolerances that are at opposite ends of the spectrum on the same car, we will see problems. The ones that get a car with parts whose tolerences are all "close to the same", we will see the freak car that natually outperforms everybodys' in stock form. Each car coming of the line will also run in varied environments (sea level, humidity, cold, etc.). For all of these reasons mentioned above, Ford's computer has an adaptive program to "try" to get the cars to all run the same (to a point of "good enough"). The program can not always compensate enough, but the car will run good enough to not set a code and pass EGR smog tests. These are the cars with "hitching." In my opinion, Ford needs to address their EGR system. It is suppossed to be able to work with NO noticiable effect to the driver or the performance of the engine. They have not designed a system good enough to do this. Until they can write a better adaptive program or they put in components that work smoother, we will not be able to get this problem fixed on stock cars.

Non-stock cars: Many do not have this problem until they change a part. If you read the above paragraph, you will understand easier why this happens. When adding a part, you thow off the "natural balance" of the car and the part introduced may be at the opposite end of the spectrum from the other parts in your car. If the computer was border-line already to be able to keep a smooth running engine while the EGR activated, then the new part (with its own tolerance spec) may push it over the edge. Because the computer's diagnostic program is not accurate enough to be able to "trigger" a problem, the mechanics working on the car find nothing. The problem is not severe enough to the computer for the computer to throw a code. You see, most of the time, if a PCM does not find a problem severe enough to throw a code, then the mechanics equipment will not sense it either. I experienced this first-hand. I brought my KB supercharged GT to an SVT dealer to let them determine if the problem with my car was Ford's or KB's. After 4 hours, they could find nothing, but admitted that there was a problem. They could not blame KB nor would they say that the problem was not Ford's. (very good people at this garage) They did find, however, that the Snap-On diagnostics was reporting random misfires, while all of the Ford testing equipment did not. This tells me that the diagnostic equipment from Ford is designed exactly like the car's PCM and it is not flagging this problem. But because Snap-On is not Ford, they are reporting anything they find. In this case, the Ford equipment considered the issue to not be reportable. In the end, the dealer said that because of the chip tune, they could not go any further because of the overrides. They thought the car was running lean, but because we did not put it on a dyno with a sniffer, we can't be sure.

So, where does that leave us? Screwed to be exact, at least if you are waiting on a Ford fix. Don't blame the dealer, they can't go beyond Ford's testing equipment (especially for warrenty). But as for the tuners, they have some control. The tuners are going to have to step up to help us because they can control the PCM and some are willing to try things. The most critical change, however, (and in my opinion) will be in the EGR tables. This is a "scary" area for tuners. The gentleman at Kennedy's garage told me over the phone that "tuners would be crazy to touch the EGR tables." Kennedys is a VERY well known KB shop. He stated that they have to be very careful because the car has to be able to pass emissions. OK, I can understand that. So..... give us switch chips that has a setting to pass emmissions for when we get tested. The other "settings" will be for performance and drivability.

I want to mention that Kenne Bell IS trying to help me with my problem. It just so happens that I also have a pinging problem. They think they have identified the problems and will be getting me a new BAP sensor and chip soon. I will keep you all updated on these issues. In the mean-time, maybe somebody can get their "hitching" car to T&J's shop and let them do a little R&D. I have a feeling that these guys will fix it before Ford will.

I have also thought of one other thing to try if somebody is willing to try it. (I would if I had enough time) It will not screw up the engine, so don't worry about that. Somebody could try to make a "restrictor" plate. A reduced EGR hole going into the intake might solve the problem. Or if it doesn't totally fix it, it just might make the problem so small that most people will not detect it. Yes, this is a "bandaid" to the "real" problem, but we have to try something. In effect, the restrictor plate would make the EGR hole "smaller" going into the intake. This would dampen the effect of the EGR. If the hole is too small, then the EGR sensor will thow a code. Another negative with too small of a hole is the fact that it will carbon up quicker at this restrictive hole.

Some people have already built EGR "blocking" plates to fix the problem. This is not a good idea. This will totally throw off the computer and definately make a code come up. Your tune would also not be good because the EGR tables are relative to the stock parameters that are expecting "some" EGR gases at certain times.

Chewing my cud on the EGR table again, I would like to make a point. Tuners program the non-egr side of the computer. Think about this for a minute. If the changes in the devices (supercharger, timing adjuster, MAF, TB, CATS, etc. etc.) throw the computer off enough that a chip has to be burned to adjust for it, doesn't it seem logical that the EGR will be effected as well? Add-ons (including blowers) make the car more responsive to changes in the air stream going into the engine. If the EGR tables are not updated to account for these changes, then it will be trying to make adjustments at certain RPMS and temperatures for what it believes to be stock parts. I am no tuner and I do not claim to be (and there is a real possiblity that I really don't know what I am talking about ), but I can think some things out logically. Again, I could be all wrong. But if I am so wrong, why has nobody come out with a fix for this problem? In the end, we may need to get a sticky started so Ford will pay attention.

Some people put the screen back in to fix the problem. Thiose people will swear that the screen is absolutely the problem. Others put the screen back in a get NO improvement. Same problem, but it only fixed one of the two. Only..... there NEVER was really a real "fix." The person who fixed their car with the screen mearly brough the car back to stock "tolerances" to where the PCM program could again compensate enough to get the car smoother. For the other guys where the sceen had no effect, his car is still out of tolerance enough where the screen did not bring the car back to spec enough for the computer to make enough changes to get it smooth. However, in both cases, the car ran good enough to pass smog tests. And this is all Ford is concerned about. Ford has to either to make a smoother operating EGR system with finer control, or they need to reprogram their computer so that the EGR can be regulated better. In the mean-time, the tuners need to get one of these "cars from hell" and do some R&D for a "real" fix. If the tuners can do this, they will be able to sell chips not only to modders, but to the average Joe to make his car run smoother. Maybe this will be enough to give Ford a kick in the buttocks so they will help us (and the dealers) out.

Off of my soap box now and Batman flame-proof underware is armed and ready.

Hmmmmm.... interesting. Restricting the EGR flow did not help...

Man, we have a tough row-to-hoe buddy.

Something has to be sending an incorrect signal to the computer. Obviously, the MAF is the first device to point to because it gets dirty, But you cleaned it. I seem to recall another guy that replaced the MAF and it fixed his problem. I replaced mine (with a 90mm Lightning) and it didn't fix my problem. Maybe your MAF can't be cleanded well enough and might need to be replaced. Did they try to swap out the MAF? Another guy fixed a similar problem by replacing his spark plugs. His was more on acceleration, however.

Then there are the O2 sensors. It could be anything with these cars. They are so sensitive!

Keep plugging away and don't give up. Eventually you will find a mechnic that will fix it. The thing with being on forums is that you see most of the problems. There are tons of Mustangs that run right. It just isn't ours for whatever reason.

I won't be trying the restrictor thing based on your results. I guess if the problem is somewhere else besides the EGR, then the EGR is just acting like the straw that broke the camel's back. I am looking forward to KB's new chip and sensor. I am sure if KB had the car, they would find the problem quickly. It sucks being so far away from your vendor. If this new stuff doesn't fix my problem, then I have no choice but to find a dyno. I have already started to look locally, but I have not found one yet.

Ultimately, I guess I could go visit my brother and have T&J look at it. No time for that at least until springtime. Oh well. I dont' know if I could even stand that freakin hitching all the way to Georgia, though.

Good luck and keep us posted.

I was over on T&J's site and Tim fixed this same problem on one of the cars he supercharged. The problem with that car was that it didn't have enough timing to burn the rich condition at a certain RPM. Personally, I can't agree or disagree with that statement, but obviously, Tim knows 1000% more than I do about these systems. I don't think more timing will help my condition because mine pings like a mother everywhere. I guess there are different problems that can give us similar symptoms. In other words, there are going to be different fixes for the hitching depending on what the real problem is for each individual car.

In your case, you might try rotating the MAF to see if it helps or makes it worse. You might even try a timing adjuster to see if adding timing helps. These are two things to try that will not kill your wallet. Especially the MAF rotation thing. Good luck.

Glad to see that your hitching is at least 85% fixed. What is happening on the other 15%?

The SVt mechanic that looked at mine noticed the random misses too (but only on the Snap-on diagnostic equipment). He started to swap out the plugs, but found that the miss just went to another cylinder. So he put my plugs back in. Man, it sounds like our cars have identicle problems. Kenne Bell is sending me another chip and a new pully to bring boost down to 8#. They think that the winter gas is causing some of my problems. The thing with my car is the fact that the hitching is less as it gets colder. It has been severely cold here for the last two months, so I can't do anything with it until it gets warmer. On the other hand, the pinging is worse as it is colder, so I will focus on the that right now. I little man on my shoulder is telling me there is a bad sensor or a bad ground somewhere. I know for a fact that grounds can act just like that. And there was a grounding issue with a certain year Mustang, but I forgot which one. Maybe ours are carry-overs. I wish somebody could tell me where all of the grounding locations are. I would take the connections apart and clean them up. I will try KB's changes first to see if that helps. I might end up having to get a scanner/logger to diagnose these problems better.

Also, when the mechanic pulled my plugs, they were white. Generally that means a lean condition. There was no red on them. However, the plugs are gapped wider than stock because they are those special pre-gapped plugs that KB recommends. I wish I had time to install my boost-a-spark kit from KB. But I don't think that it operates in a vacuum condition (where the hitching is).

Let us know how the cars continues to run and what the other 15% is doing. My guess is that there is still a problem, but the new plugs are helping to over come some of it with a healthier spark. Was the heat range different on the new plugs?

Maybe we are going about this the wrong way with the wrong thread. Maybe we should be looking for people that have fixed confirmed random misses. We both know that the EGR valve has an effect. However, that effect may be detectable because of an underlying problem. That underlying problem may be what is causing random misses. If there is a marginal problem, then when the EGR opens, it changes the Air/fuel ratio enough to cause the random misses. It seems more than a coincidence that both of us have 03 GTs with the same identicle problem. On the other hand, I have some pretty serious mods that makes mine a lot different from yours. Oh well, who knows? With the both of us trying things, we have a better shot at it. At least you have made some headway.

Any vehicle you try cruising at 1500 rpms in a high gear at low speeds
its gonna be groggy. Unless its a diesel truck.
I try to keep my rpm at least 1800 or higher.
But this is just my opinion of almost every stick I've driven.
I'ts a lot more noticeable if you have exhaust mods.

i have yet to figure my hitching problem out...........but it is very bad & has done it as high as 3300rpm's.
mine is sooooooo beyond subtle............i mean cars driving next to me can tell. it is like your kicking the gas trying to snap everyone's necks in the car

NEWS FLASH! (excuse the pun)

Cobra Killer has a computer re-flash that will fix this problem! He said that he can fix it on ANY car. I have PM'd him with more questions, so I can't give you exact specifics yet, but the fix is in a table that a chip can not go. It sounds like it is a problem with the factory tables. Given Fords record for fixing things for us, don't hold your breath waiting on a fix from Ford. Tim has not announced whether or not he will try to fix people's hitching/bucking/surging/shunting problem or not. But he said the fix is now easy for him to do and he has tested it on a couple of cars.

From the sounds of the problem and the fix, the problem can arise when a car is modded or not. As I mentioned before, the problem seems to occur after even small mods. My guess is that there is a table that needs to be modified whenever certain mods take place. This table apparently is not effected by chips. My "guess" is because it is in the "learning" part of the computer algorythms. (or maybe in the EGR tables like I have suspected all along!)

Hopefully Tim will help us out. I have a KB with a chip, but if the chip can't modify the correct table to fix the problem, then there is no hope for me. I do know, however, that Kenne Bell can flash computers as well. The catch here, however, is that Tim seems to be the only tuner in the world that knows exactly what the problem is and how to fix it. I can't say I blame him if he keeps it a "secret." But like I said before, hopefully he will at least "sell" us a fix in the form of a reflash of our computers. He has had the hitching problems on his installs so he was highly motivated to fix it for his customers. The man IS dedicated beyond belief!

If you would like to learn about the fix, then try emailing him. Maybe if he sees a lot of interest, he will help us out.

Badd GT said:

it is like your kicking the gas trying to snap everyone's necks in the car

Click to expand...

The mental picture is funny as hell.

This problem isn't isolated to the KB chips. I didn't have this problem until I had the custom program Autologic chip installed in December 03 on my 99 GT. It has progressively gotten worse over the last 2-3wks. We have had tempature fluxuations from -20 to 40 degrees, I wonder if this is contributing to the problem? I plan on pulling the chip out this weekend to see if the problem goes away.

One car had bucking in heavy loads down low.It took timing to fix it.

the other "hitching" at cruise was hard to find.Actually took me 18 hours with the car to find it.Its in 4 sperate tables.Its the way Ford has the template set up.I actually found it by mistake and out of pure frustration..It was one of those,alright damnit,what is going on..I actually made an adjustment if 4 diffrent tables.I made the bucking @cruise WORSE..That told me what I needed to know.I simply went back to those 4 tables and did the exact oppposite programming in the other direction.Its fixed..I also figured out the idle hang the 99-00's have..That is fixable now too..

I have about 50 plus street hours fixing both these problems..
Timing wont help the bucking while cruising,it takes adjustments in 4 seperate tables.One is a preset parameter the car goes to under 20-40% load(cruise load)...That is the one i found totaly by accident.It is what cured it completely.
Im going to test it on one other car,after that I'll P.M Mike Raburn and let him announce there is a fix for the problem..

Tim

I fixed another one last week for a local guy with an 03.....The computer has to be reflashed with a new file to correct it.It involves a few tables and isn't something a Ford dealer can do..
I cant offer help because its advertising under stangnet rules.Ya'll are welcome to see if Mike Raburn will allow a thread to be started about the fix,until then,I cant really help much..

Tim

Tim you are the man , by the way my car is running great .

Glad to here it....