difference between A9L and explorer computer

gorgo · Post by **gorgo** » Tue Jan 30, 2007 11:58 pm

does anyone know what kind of difference there will be between a 98 exoplyer performance and running the same motor(5.0l) with an a9l in a 93 long box ranger. the exployer was a awd the ranger is a 4x4.
i would have to believe the exployer weight is alot more than the ranger,
i was just curious in what i should expect with the swap. the exployer was
no slouch for a suv. i drove it before i stripped it bare and haul it off saturday. im just using the stock set up. only difference is the a9l computer

stranger · Post by **stranger** » Wed Jan 31, 2007 4:47 am

so long as you have the supporting sensors and wiring for the a9l.different pcm family.ecc iv for a9l,eccv for explorer.,what trans?

cgrey8 · Post by **cgrey8** » Wed Jan 31, 2007 7:36 am

I take it you have an Explorer computer and motor that you want to run instead of retrofitting the motor back to Mustang sensor/distributor standards to run the A9L? It can be done. But without a tuner of some sort, there may be parts of the Explorer's EEC that want to control and monitor things your 93 Ranger just isn't going to have. If you aren't using the trans setup the Explorer EEC expects, then you'll have issues there too.

Most of this stuff can be turned off in the EEC's tune. And any performance related parameters such as timing that are more conservative in the Explorer EEC can be tweaked as well. It's just a matter of getting a tuner to do it. But finding an experienced tuner to do it right may be difficult. The people that burn tunes have a lot of experience with LOTS of different tunes, but are usually only experts at a handful of the more popular tunes like Mustang/Cobra/Thunderbird tunes of various years. So they generally only mess with generic parts of the tune on EECs they aren't as familiar with. The Explorer isn't exactly a performance vehicle so they don't have nearly as many people pulling in their modified family SUV to be tweaked up as they do Mustangs.

Some people say that shouldn't matter, and for generic things, they are almost right. Things like adjusting timing, injector slopes, and MAF Curves are all very generic. These are the things that ANY tune is going to get tweaked...and the procedure for tuning these is pretty much universal. However this only gets your tune good enough. But as a do-it-myself tuner, I've come to realize there are LOTS of places in a tune that you really need to know about to do an effective job with drivability. Otherwise, you may end up with a very nice WOT, but be asked to live with drivability issues at non-WOT conditions because the dyno shops simply don't have the time to tune your engine for every possible driving condition you will experience. The best they can do is come close...and guess on the rich side. As a driver, you'll never know if the engine's running just a tad rich. But it'll be quite obvious if it ever runs lean. The vehicle will hesitate, surge, and buck the worse the lean condition gets until it finally just conks out.

If you want to tune it yourself, you'll need a device like a TwEECer or EEC-Tuner. There's a learning curve to doing it yourself, but if you are into that sort of thing...they can be a lot of fun. And if you go with a mainstream processor like the A9L, there's lots of experience and support out there for them. The TwEECer does support most all the Explorer EECs, but I can't name 1 person on the tuning boards with hands-on experience using any of the Explorer EEC strategies.

Now that said, lets say you got some experience using a well known EEC like A9L/A9P/A9M (89-93 Mustangs) or the T4M0/W4H0/U4P0/J4J1 (94-95 Mustangs), then you could transition to tuning your Explorer EEC with much greater effectiveness. Bottom line, for someone that's interested in tuning their own vehicle with a TwEECer, I would NOT recommend they learn on a non-standard EEC. But for anybody with a moderate amount of tuning experience with Ford EECs, it won't matter quite as much.

gorgo · Post by **gorgo** » Wed Jan 31, 2007 9:09 am

im using a A9L computer, c4, and a mustang harness and dist

Dave · Post by **Dave** » Wed Jan 31, 2007 9:12 am

Gorgo, I saw the weight a couple of years ago of the Explorer, compared it to my Jeep. The Explorer at that time was around 4100-4200#, probably more now.
Dave

cgrey8 · Post by **cgrey8** » Wed Jan 31, 2007 9:36 am

Using an A9L on an Explorer motor...I don't see a problem. You'll want to:

1. Retrofit the motor to Mustang sensors (including the MAF)

2. Install a 302 TFI distributor

3. Replace injectors with 19lb injectors and use a stock Mustang MAF OR install larger injectors with a MAF matched to your injector size

4. Install a return-style fuel rail if your 98 Explorer motor is setup for a returnless fuel system.

5. Rewire your harness for any sensors that aren't where the Mustang located the sensors. The ACT, TPS, IAC, EGR solenoid/pos sensor, and MAF will be the most likely wires to need lengthening/relocating.

6. If you plan to delete the EGR, you'll need to tune the EEC for that or install a dummy feedback device on the EGR's position sensor connector.

At this point, having a tuner tune your setup would get you maybe an additional 10-12 horses at WOT. But you may still have minor drivability issues. Most people can deal with what the A9L gives them with no tweaks at all. But if you are looking for perfection, you'll want to get a TwEECer to fine-tune everything. I've got this same exact setup using a 97 Explorer motor on an A9L with a TwEECer RT. The RT indicates it does datalogging and is a must for EEC-IV era controllers. The tune I run with my TwEECer would get you 90-95% of the way to where you want to be including disabling the Thermactor (smog pump) controls. The only things that'd need to be tweaked would be putting your injector size and exact MAF curve in, downloading it to the TwEECer, then fine-tuning from there...

stranger · Post by **stranger** » Wed Jan 31, 2007 11:07 am

98 has returnstyle.99-01 are returnless

cgrey8 · Post by **cgrey8** » Wed Jan 31, 2007 11:23 am

stranger wrote:98 has returnstyle.99-01 are returnless

I couldn't remember when that switch happened.

What about the injectors? Had the 98s moved over to the EV6 17lb injectors? My 97 used the EV6 style 19lb injector with an EV1 style connector...thus the Mustang harness fit the injector's connectors. It would've solved me a lot of problems if the connectors hadn't fit forcing me to upgrade the injectors way back when I had the motor on a stand and the upper intake off. But with the TwEECer, I've made it work.

gorgo · Post by **gorgo** » Wed Jan 31, 2007 1:54 pm

my exployer motor doesnt have a smog pump, has 19lbs injectors with the same plugs as the mustang. the mas sensor has the same number of wires as the mustang harness just changed the plug. already lenghted the sensor wires, has a return gas line. ordered a egr eliminator from fordfuelinjection.com (of course it is backordered). everthing else sould work. the tune i will have to deal with when i get it running.

cgrey8 · Post by **cgrey8** » Wed Jan 31, 2007 2:22 pm

The wires may fit, but they are not the same injector as was used by the A9L in the Mustangs. The ones you have are 19lb, but they do not behave exactly the same as std 19lb EV1 generation injectors (what the A9L is tuned for). They are EV6 injectors that just happen to have an EV1 connector. Don't go down the path I went and try to make them work anyway. Replace them with Mustang 19lb injectors. Those old EV1 19lb injectors are quite easy to come by since most modded Mustang motors ditched the 19lb injectors 1st thing and upgraded to higher flowing injectors. Or take the opportunity to upgrade to a set of 24s yourself and get a MAF to match.

To read more about this issue and the problems it caused me, check out this thread:
Questions about injectors

I was able to overcome this issue by tuning the EEC for the differences in behavior. But if you aren't planning on a custom tune, then it'll be worth your time to replace those injectors.

However, you may need to plan on a tune anyway if you are deleting the EGR. If you don't delete it in the tune or put a device on the wires to fake-out the EEC into believing the EGR is working, then you risk running the EEC in limp-mode all the time. I've never run my engine for any length of time in limp mode, but from what I understand, it pulls timing and over-enriches the mix to protect the engine. My recommendation would be to maintain the EGR. The EGRs today are not like they were in the 70s and early 80s. They actually have a positive performance function and are beneficial to mid-throttle performance and fuel economy:

Refer to this thread for details on what EGR to use and how to mod your elbow to work:
Are these two EGRs interchangeable?

Refer to this thread for details on how I fabbed myself a custom tube up to my EGR:
Will copper pipe actually hold up to EGR gas temps?

The smog pump (aka Thermactor)...talk about useless as tits on a bull. 100% emissions devices. I don't know this for sure, but I think the OBD-II standard requires that vehicles pass emissions without the aide of smog pumps. The EPA realized that all the smog pump was doing was diluting the exhaust with outside air so the measured Parts-Per-Million of exhaust pollutants wasn't so high and would come in below the required threshold. The engine wasn't really burning cleaner, the exhaust was just getting diluted under the pretext that the extra oxygen helped the CATs to do their job. They are right, the CATs do need oxygen to do what they do, but I don't believe the smog pump's success was because they were helping the CATs as much as the outside air was simply diluting the exhaust mix. Because all V8 Explorers were OBD-II, the Explorer 5.0L motors didn't have smog pumps. So how did they pass emissions? Higher quality CAT converters and a head redesign (i.e. the GT40p head that came out early 97). Here's some good reading on the GT40p head:
GT-40P. Is the P for Performance, Pathetic, or Pain-in-the-Ass!?

But since the A9L was an EEC used during the thermactor days, you'll need to defeat it somehow. You can put thermactor solenoids on the wires to fake the EEC out into believing the controls are there and working. I've also heard you can put resistors on the wires so the EEC sees something that appears as the solenoids. But either way, if you run an EEC diagnostic, the EEC will realize that the thermactor controls aren't working and will throw codes anyway; at least it won't throw codes and put you in limp mode going down the road. It'll only flag problems if you run a diagnostic. With a custom tune, you can disable the A9L's thermactor controls so it doesn't ever throw codes about the Thermactor.

MalcolmV8 · Post by **MalcolmV8** » Thu Feb 01, 2007 7:59 pm

cgrey8 wrote:But since the A9L was an EEC used during the thermactor days, you'll need to defeat it somehow. You can put thermactor solenoids on the wires to fake the EEC out into believing the controls are there and working. I've also heard you can put resistors on the wires so the EEC sees something that appears as the solenoids. But either way, if you run an EEC diagnostic, the EEC will realize that the thermactor controls aren't working and will throw codes anyway; at least it won't throw codes and put you in limp mode going down the road. It'll only flag problems if you run a diagnostic. With a custom tune, you can disable the A9L's thermactor controls so it doesn't ever throw codes about the Thermactor.

I have resistors on my red truck (compact clean look hidden in the wiring loom) and solenoids plugged in on my blue truck (doing nothing but completing the electrical circuit). Neither truck throws any codes, not while driving or running diagnostics.

Malcolm

cgrey8 · Post by **cgrey8** » Fri Feb 02, 2007 6:45 am

I wonder why that is. When I run diags on mine without the TwEECer activated to disable the Thermactor, I get codes indicating that the Thermactor isn't working. Hmm...

So, I guess its hit-or-miss.