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New to me 02 kenne bell gt issues

6K views 62 replies 10 participants last post by  matholland 
#1 ·
Hey guys! I just got home with my new to me 02 mustang gt. Car has 60k miles on it with a kenne bell 2.1, mmr 750hp block. It got dyno'd today and has a 3" pulley. It made 459hp today and was only building around 11psi. I guess the guy at STL mustangs told him he needed to go down to a 2 5/8 or 2 3/4 pulley with a bigger MAF and would be around 525-550hp. It apparantly has a 90mm on it now....This is my first supercharged car. I picked it up for 9650 and its super clean. Anyway, the car runs great, but there is an issue when you are low rpms and start giving it gas under a load...say 5th gear, 2200 rpm, and you lay into it...it will cut out until it builds up to around 3k or so and stop cutting out. Revving it up in neutral will do it, and I have noticed the idle has hung around 1500 rpm a few times until you blip the throttle. Check engine light only has one code and it is the p0125 coolant temp sensor. Any ideas on where I need to start?
 
#2 ·
My engine is NA but a few months ago I was having identical problems. One or two of the COP boots went bad and I wasn't getting a good spark causing a misfire but not throwing any codes. Check your plugs to make sure they're clean and gapped properly, and try moving the COPs to different cylinders. I moved them around and was able to throw a miss fire code. I replaced all the COP boots and the issue went away. They are cheap so I would replace them all especially if they are original, and use dielectric grease or silicone. It keeps the water out and promotes a clean spark.

BTW - sweet mustang. That thing is going to be fun.
 
#4 ·
Could be a coil or poorly gapped sparkplugs.....or it could be a shitty tune. I'd data log it if you have the ability

---------- Post added at 07:23 AM ---------- Previous post was at 07:23 AM ----------

And fyi, don't boost in overdrive.
 
#5 ·
I know for sure it was at stl mustangs yesterday and him going through it. From what I hear it's a very reputable Shop. Apparently they changed a few coils from stock that guy had of oem coils so you guys might be on to something. Looks like advanced auto has the accel supercoils in stock. I think I'm going to pick those up today. What should my plugs be gapped at with a sc application? I don't currently have a way to datalog. I do not have a handheld tuner for this car. Thanks! It seems to run pretty good! It was wet and rainy on my way home so it was hard to play with it any.

I appreciate the info guys!
 
#7 ·
If you are close to STL I would take it to Mustang Muscle in High Ridge, MO. Matt is a great guy, knows his ****. I highly recommend Mustang Muscle.

Does it cut out in every gear under load? If coils are the issue it would be cutting out in every gear under a certain amount of load.

Check the plugs and coil boots first before buying new coils. No reason to throw parts at it. Start ruling stuff out first.
 
#8 ·
I'm about 2.5 hours from STL, but there is nowhere around close to me other than STL that does this stuff. Thank you for the suggestion! I will definitely be on the hunt to take it somewhere when I decide to put a smaller pulley on it and have it re-tuned.

It does cut out in every gear under a load lower RPMs it seems with a certain amount of throttle given and the same goes for neutral. Keep in mind, I only drove it 2.5 hours home and it was wet...I haven't driven it anymore yet lol....If I am cruising at say 2k RPMs and I barely give it more throttle it won't cut out, I push it to say half and it starts cutting out.

Sounds like everyone is thinking it's coil related. I will pull them out tonight and take a look at the boots and stuff and go from there and let you guys know.
 
#10 · (Edited)
I checked things out, plugs looked fairly fresh, there was di-electric grease on the boots of the spark plug and on the ends of the COPs. All the boots looked good. The only issue that I noticed is one of the COPs bolts is stripped out on the passenger side. I mean the bolt is in there, but it will pull out. I know these COPs have a spring in the boot, but they seem to fit pretty securely. I was going to grab some JB and put in the hole, thread the bolt in, let it set up, and unscrew it then put the COP back in. I'm not sure if that is causing an issue or not. My buddy had a new set of ford motocraft COPs. I put those in last night. Same thing. It isn't as bad once it warms up as it is when it is cold, however it is still pretty bad when it is warm as well. I cleared the code for the coolant temp sensor (p0125). I know on my Jeeps, this sensor could cause lots of running/cutting out issues. Does that do that on these cars as well?

Something else, the guy told me that the car had 90lb injectors. I have not ran the numbers on them yet, but isn't that an extremely high injector for my application? Shouldn't I be running around a 42lb? Could it potentially be getting too much fuel? It does have a narrowband air/fuel gauge in it, but when I turn the key on it displays ---. When I start the car it counts down from 17.0 to 0 then stays at 17.0 and doesn't ever move. I traced the wiring, and all the wires go to the narrowband o2 sensor, ground is grounded and power has power...Not sure why it isn't working.
 
#11 ·
Get yourself a wideband.

It could be tune related if brand new coils didn't fix the issue. I would get that Coolant Temp Sensor fixed. It's very easy to replace and very cheap to buy.
 
#12 ·
Sorry I said narrowband, it is a wide and with the bung welded to the exhaust but it isn't reading I tried to trace some stuff last night. Going to do some more tracing and see if I can find something. It just reads 17.0
 
#13 ·
An improperly seated COP could be causing issues. Try and get it properly seated and see how that goes. The COPs you used, did it include the entire assembly (coils and plugs) or just the plugs (top part)? When you inspected the boots did the coils extend the entire length of the boot or did some/one seem shorter?

90lb injectors seems way overkill for this car. Is the fuel pump stock or is a higher flow rate pump? My understanding is that even though the injectors are big the car will only pull as much fuel as it needs. Someone else might be able to shed more light on this though. If it's running rich you should be able to smell the fuel in the exhaust and there would be black soot on the bumper and exhaust, also the plugs would be black with carbon deposits. This would be more difficult to determine if the seller cleaned the car and replaced the plugs. It wouldn't hurt to clean the MAF and replace/clean the air filter. Maybe even pull the upstream o2 sensors to make sure they look clean as well, because if the car was running rich they would be a clogged up and might not be reporting correct numbers. Data logging will be your best friend.
 
#14 ·
I'll get it rigged up to where it holds the coil down tight and see what happens after that, and also get a new coolant temp sensor, and try to track down the wideband some more and see if I can figure anything out on that.

As far as the coils they had new boots on them and they all seemed the same length and they all sucked down more when I tightened the retaining bolts.

I'm wondering if the guy had a typo when he sent me the message about 90lb injectors. It is right by the 6 and 60lb injectors from my research would make much more since. I'm assuming there is numbers on them and I'll run the numbers when I fix the coil bolt tonight after work.

The fuel pump is a cobra pump with a kenne bell boost a pump in the trunk. From what the guy said the dyno guy said is that the fuel pump had plenty left to run a smaller pulley and be around the 525hp mark. I wasn't there when it was being done, that's just what the guy said. The guy lived in a real nice neighborhood and seemed like a very picky guy. Seemed like a real honest guy.

Air filter is new it's a jlt Cai. I'll clean the maf as well. Would I be worthwhile to buy an sct x4 through american muscle where I can get free tunes for life as well so I can do some cataloging? Probably not the best place to have write me a tune but if they can read the catalogs and stuff and get a safe tune on it that's close and my problem goes away then I would know it's definitely in the tune right?
 
#16 ·
Try recalibrating the Wideband. Look up the specific instructions on how to do that for your specific brand. Mine was VERY easy to calibrate (innovate).
 
#17 ·
It has an Autometer Wideband...from my understanding, the Autometer's don't need to be calibrated. I don't think there is any instructions for them. I would look it up, but I don't remember the model off the top of my head, so I will have to look it up when I get off. As far as writing a tune on top of another...I had a 2000 that had a tune on it and the tuner got stolen. I was able to buy a new tuner and overwrite what was there. It took the current tune that was on it and saved it as the "stock" tune. The guy said that he did not have a tuner. I have never been to a dyno shop, so I was assuming they could write the tune to the computer without the need of having a tuner with their laptops.

Without having an SCT x4 or livewire, I cannot do any data logging correct? I will reach out to see if that shop will tell me some info.
 
#18 ·
Like I said, at this point I would contact SCT to see if you'll be able to get the current tune off the car and have it saved as the "stock" tune. If you can do that then you won't have any issues. If you only want it for datalogging, there are cheaper ways of going about that as well. I used Delta Forces tuning software and used their datalogging software. I really liked the display and the datalogs were easy to understand once you pulled them into excel.

I'm almost positive I used the Auto Meter wideband on my 2000, and it uses the Bosch ugeo wideband sensor. You do have to calibrate it for the correct lambda for the fuel you're using. You can also have it display in lambda or in AFR... I preferred AFR. IIRC the calibration was very simple and took only a minute or two to do. You can probably look it up on Google.
 
#19 ·
I got a hold of the guy at stl mustangs. He remembered the car and didn't have anything bad to say about it. He said that he did remember that the maf sensor was just about maxed out. He said he didn't have the datalog in front of him, but from what he remembered the fuel system was fine and he thought that it was 60lb injectors in it. I didn't get to talk to the guy that did the tuning on it, this was from one of his employees. I have a Bluetooth obd reader, I also have a laptop with Bluetooth. Is there some software I can get to do a datalog?

I told him I was about 2 and a half hours away and he said that they would look at it again. I feel like if I was going to run it over there then I would want to go ahead and get another maf and a smaller pulley to get more out of it as well.

I'm still going to check over things when I get home tonight. Where does one find a maf bigger than 90mm? It seems like 90mm is the biggest I've found.
 
#22 ·
That's what I figured, I will probably get a smaller pulley as well. Was hoping to not have to put it back on the dyno for a retune in effort to fix the issue. What is the difference between that one and the 90mm one that I have which is model number afh90-02?
 
#23 ·
I got my wideband fixed. It was some broken wires. They got caught on the steering shaft I guess and previous owner just taped them up. Wot when it's cutting out shows a 10.0 on the air meter assuming that it's accurate. Cruising it's 12.5-13.5 at 2200rpm
 
#25 ·
It also idles in the 10s. I'm going home now to get my Bluetooth reader and I'm going to fire up torque and see if it can read the maf voltage. I also fixed my bolt where it will hold the coil down, still cutting out...is it weird that at night maybe when the air is cooler that it isn't cutting out as bad?
 
#26 ·
So what is the difference between the SCT 2600 and the 90mm cobra MAF that I have now? I'm open to buy one, was just curious since mine is also a 90mm. As far as the data logging. What's the best way for me to go about that? I want to get my ducks in a roll like someone else mentioned, make sure it isn't an issue with the car vs the tune. I almost feel like it would be a good idea to go the tuner route and buy the MAF.....I know AM tunes do not compare to a dyno tune, but I would be able to datalog, plus be able to get a tune from them and see if it does the same thing (since their tuning is free if you buy the tuner from them). Just thinking out loud here. See if that helps then assuming it does, buy a smaller pulley and take it over to have some more dyno time?

It does have 60lb injectors. I have NOT changed out plugs or cleaned the MAF. Any other thoughts or suggestions as to the best way for me to go.
 
#28 ·
That blows that idea out of the water then lol.

---------- Post added at 10:08 AM ---------- Previous post was at 08:23 AM ----------

Alright another update.

I talked to Bob, the guy that actually did the tuning. He said at 6100rpm I believe it was, the MAF and the fuel pump are both about maxed out. He said that the blower was at 85% and gave me a few options. He said that the day the guy brought it in and they tuned it, it was pouring down raining and he had the wiper delete plates on it. They did not get to drive it on the street and said that's not usually how they did things but the guy wanted it back. He told me if I was happy with the power, then I could bring it back over and it probably wouldn't take him long to get things lined out. Said it is probably in the tune. He said I could get like a 2 7/8 pulley and get a little more boost out of it, upgrade fuel pump and MAF and get about 40 more hp out of it. I told him I was happy with the power it was making if it would run right. I don't really see it being worth it to upgrade the fuel pump, MAF, and a little smaller pulley just to get 40hp out of it. So I am going to take it back over to him next week and hopefully get things lined out on it.
 
#30 ·
Put a stock one back in. A lot of guys put 160s in like me but you need the fan settings changed for it to be efficient....but thats more if you are overspinning and need to try to combat heat problems before it becomes a problem. lol. You aren't really at that point.
 
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