98 explorer ecu with big cam

[98V8RANGER]

Has anyone tried blocking off the IAC and just use the tb to controller idle? Saw a guy on another forum said he did this and it worked well. Once he blocked off the IAC he used the tb adjustment screw to get the vehicle to idle. Then he disconnected the battery to reset the tb sensor. When I get my engine in I am going to try this.

[cgrey8]

You can try, but I doubt it'll run really great for you. If all you care about is idle and WOT, then you can make pretty much anything work. But if you want good drive-ability then that may be where disabling the IAC and tinkering with the idle screw won't cut it.

Common drive-ability issues range from cold crank quality, cold drive smoothness, warm cruising fuel economy, smooth tip-ins (typical acceleration from stops, not hotdogging), etc. Big cams are already not well suited for "daily driver" duty, but with a custom tune, you can minimize their downsides and depending on just how radical the cam is, you can tune away all the side-effects. But the days of being able to fool the computer like you could on the late 80s and early 90s computers left with EEC-V (all 1996-newer EECs) and the last EEC-IVs (most 93-95 EECs). The nice part is a lot has matured in the DIY tuning arena. And while professionals can do a lot, they are NOT often the best ones to tweak driveability issues just because it is so difficult to predict what the engine will do in every possible driving condition that can't be reproduced in an hour or so on a dyno. When it comes to drive-ability issues, you are the best person to tweak those areas of the tune as you find scenarios that don't run as well as they could. If you are interested in diving into the tuning pool, you can do quite well as long as you have a laptop, a budget of about $800 to spend on tuning hardware & software licenses, and are willing to tinker. It's not plug-n-play. And there's a lot of concepts in tuning that aren't exactly obvious or intuitive. But with the forums, you can learn everything you need and ask questions specific to your scenario. The quality of your responses will depend on how much info you can supply.

[plowboy34]

A friend of mine had a Tempo that suddenly the idle went really high. The IAC had gone bad, he had no money so I cut a piece of cardboard just like a gasket except it just had the two bolt holes, I left the rest solid to block it off. The car idled just fine and he ran it for 3-4 years before selling the vehicle.

[98V8RANGER]

Thanks for the info cgrey8. I am no stranger to tuning, I have a 90 Tbird SC that I work with all the time. I race it every weekend. What is the catch code of the 98 ecu that people have problems with? I have a 1997 ecu from a Mercury Mountaineer, my catch code is XDT2. Mine might not give me the problems that others with the 98 ecu have experienced.

[cgrey8]

The only problems I'm aware of are with PATS on the newer EECs which start at 98. The 96-97 EECs didn't have enough memory to do PATS with only 2-banks of memory which is why in 98, Ford went to a 4-bank EEC. Lots more memory and lots more annoyance from things like this. Of course, if you have a tuning device, you can quite easily turn the PATS stuff off if your definition file supports it, and I believe most do since that's a common thing to need to disable when moving EECs between vehicles.

The XDT2 is the same Explorer EEC I have. I keep telling myself I'll one day use it for something. But it's so difficult to talk myself into a retrofit when my setup works so well, I know the strategy of my EEC inside-n-out, and there's little I can't make work with what I have...that I want to do. Now if I were running an automatic, the newer EECs would be nicer since they do transmission control.

The only other PITA about the newer EECs is Ford went away from VSS sensors and instead get Vehicle Speed from the ABS system to save on the cost of VSS sensors & wiring. What I don't know is if the newer EECs can physically still read a VSS if you wire one to the port the VSS used to wire to...another reason to stick with the XDT2 since it used a VSS.

BTW, what are the specs on that cam?

• Max Lift (assuming 1.6RRs)
• Duration@.006"
• Duration@.050"
• Intake Lobe Center
• LSA or Exhaust Lobe Center

[Teddyzee]

With regards to blocking off the IAC, I've done that on my 5.0 Ranger, and also on my 4.6 Mustang.
I used a solid gasket. I have since wapped to a normal gasket on the Ranger (no particular reason), but my Mustang is still blocked off, and drops to 600 RPM immediately when the clutch is pushed. I just enjoy this more than having the thing idle at 1600rpm...

[98V8RANGER]

cgrey8, I haven't decided on a cam yet. It will be the f303 or the x303.
The reason I brought this subject up was because I had read where people with a cam that had more than 112 lsa where having trouble getting them to idle. I could set my idle at 1000 rpm if I wanted to. I am going with a 2800 stall converter.
cgrey8 what tuner are you using?

[cgrey8]

cgrey8, I haven't decided on a cam yet. It will be the f303 or the x303...

Those aren't bad cams. But there are better cams out there. All of the FMS cams have rather "weak" ramp rates. They are a product of 80s technology meant for use on stock and ported heads that were available in the 80s and early 90s. Granted, they'll still do what they always could do. But I just feel there are better cams for producing the power they can while getting better driveability particularly if you have higher flowing heads like RHS, TFS, Edelbrock, or AFR heads. Higher flowing heads can produce power with a much lower duration cam...big duration is where drive-ability issues come from.

...The reason I brought this subject up was because I had read where people with a cam that had more than 112 lsa where having trouble getting them to idle. I could set my idle at 1000 rpm if I wanted to. I am going with a 2800 stall converter...

I suspect idle problems are more related to cams with LESS than 112 LSA. Stock cams commonly have 115-118 LSA. Traditional aftermarket "big" cams usually are in the 110-114 range. And yes, I agree, 112 LSA should be considered your limit. Unless you are doing serious racing, going less than 112 doesn't often make sense.

Being you are talking F303 or X303, my gut feeling is the Comp XE274HR12 is going to serve you far better. It has higher lift, similar .050" duration, and less off-the-seat .006" duration which MANY people have run and had great luck with in both NA and heavily boosted engines.

...what tuner are you using?

I'm using a Moates Quarterhorse (QH) tuner/datalogging device. The software I tune with is BinaryEditor (BE). And I analyze the datalogs with the help of EEC Analyzer (EA) which is written and sold by the same guy that wrote & sells BE. I used to use a TwEECer RT, but ever since the QH became available, my TwEECer stays in a drawer. The TwEECer is sold by a guy that's content to just sell them and collect the profits and do nothing else. He got someone else to design the hardware and had a mediocre programming skill to write the software to communicate/control the thing as well as decipher the stock tunes. Most of his deciphering work though is spotty at best and shouldn't really be trusted. The developers of def files for BinaryEditor are far more complete and accurate than the crap that's in the TwEECer's software, called CalEdit.

The QH is actively being maintained and the hardware developer that makes them also makes stuff for Chevy and a number of different imports. Also he focuses only on making the hardware. He doesn't pretend to write the software. He assists others that are better at it than he is so he can focus his time where his time is best put and that's designing, selling, and supporting hardware.

I also use an Innovate LC1 Wideband controller. I HIGHLY recommend if you are wanting to enter the DIY tuning arena that you invest in a WB. Trying to tune fuel without one is tuning blind. You might as well be twisting screws on a carb if you aren't going to invest in a WB.

Here's all the info I think a person considering DIY tuning should know:
Things to know BEFORE buying a TwEECer or Quarterhorse

[98V8RANGER]

cgrey8, does the quarterhorse have transmission control?

[Grumpy]

98V8RANGER ... dude one piece of advice on the cam .... watch out for valve to piston interference as some of the engines wont run a cam bigger then the B or F ... im running a 90 5.0 out of my Mustang GT and have a X cam in it ... it dont hit because it has the valve reliefs that will let it run the X cam... most(or at least some) do not even have valve reliefs in the pistons .. so be careful on which you choose as it can DESTROY ya engine if they hit each other !!!!! .. i know this from experience as i worked in a couple speed shops and know this can happen .... ok.. was just a bit of info that i thought ya might take into consideration on a cam choice ....good luck ......

[98V8RANGER]

grumpy, thanks for the heads up but I always check piston to valve clearance when I assemble an engine. You are right, one mistake and it is all over but the crying.

[cgrey8]

cgrey8, does the quarterhorse have transmission control?

Transmission control is a characteristic of the EEC you are tuning. If the EEC can control a transmission, then the QH can modify the tune that runs it. If the EEC cannot control a transmission, then having a QH isn't going to do anything for you. The QH can't add functionality the EEC doesn't already have.

The QH can "activate" functionality that the stock tune had turned off from the factory though. On the 89-93 Mustang EECs, there are a few different modes that the code supports, but Ford chose not to allow to run. One is the ability to turn off the injectors while at deceleration. The other is the ability to run lean-cruise. Both of those can be reactivated if you like.