automatic ecu in my 5 speed

[01momogti]

Aside from getting a few cel codes from the auto ecu, will the automatic ecu cause any issues running my 5 speed truck other then codes? ie. Worse fuel trim, less timing Ect...

 

[Maniak]

I've "heard/read" that the manual ECU does have a different timing curve than the auto ECU..

If you are worried about the TCC and 3/4 solenoids not being found you can put in 33 ohm resistros where those solenoids used to be. I did that our our '92 when I swapped the a4ld to the 700r4.

Since then, I have removed those resistors and I don't get a CEL BUT, if I check for codes I have a code for the 3/4 and TCC solenoids. I actually like having those.. If I read the codes and don't see those then I know I misinterpreted the codes..

~Mark

 

[Gadget X]

I have been running g mine with the auto ecu since I did the auto to manual swap about 6 months ago. The only "issues" I have had are that the idle is a little higher, and takes a second or 2 to come down when I come to a stop. I have had no codes, but I also took the transmission harness from the donor vehicle. I just plugs into the same connector the auto transmission harness plugs into on the drivers side wheelwell.

 

[jmdirk]

Been running a '92 auto ECU in my '93 swapped to 5 speed for a few years now. Never noticed any idle issues, but never really paid attention either. To get rid of the MIL I pulled the solenoids out of the auto and wired them up under the hood to fool the ECU into thinking they are there. But the 33W resistors would be a much cleaner install.

 

[Anime]

The stock 4.0L OHV has a different camshaft and different timing curve between the manual and automatic versions.

You don't really want to use a manual transmission ECU on an engine that came stock with an automatic transmission behind it and now has a swapped-in manual transmission.

The only way I'd suggest putting the ECU for a model with a manual transmission on would be if the stock camshaft out of an Explorer with manual transmision were also used, so the timing would be correct.


You'd probably get worse performance and worse fuel economy using a manual transmission ECU with an engine that came with an auto trans, and that still has the auto trans camshaft and so requires the timing for that.

 

[01momogti]

Well the deal I have is my truck is a factory 5 speed with an automatic ecu.

 

[Anime]

You definitely want to keep the manual ECU with the 5-speed if that's the way it came from the factory.

With the 3.27 gears and the larger, heavier tires, it needs all the torque it can get.

Using an ECU for an auto will just cause poor performance and poor mileage, if it is even the correct ECU for the same year.

ECUs are year specific, with certain codes. You definitely don't want to put an ECU from a 91-93 Explorer in a 94 Explorer, either.


If you are having ECU issues or need a replacement, I'd suggest getting a refurb ECU with the same part number that is on the factory unit.

 

[01momogti]

Ok I will look into finding a refurbished one thanks, surprisingly she has plenty of power still with the 33's and the 3.27s. The 5 speed does very well in this truck. It doesn't feel any slower then our toyota with 32s and 456s. Looking forward to the 373s I have sitting in the garage, although it doesn't feel like it needs them at all.

 

[jmdirk]

Any difference in the timing curve would be programmed into the given that it's an electronic ignition.

91 and 92 had different camshafts between manual and automatic. 93 and 94 have the same camshaft between manual and automatic. There are different camshafts for federal emissions vs. Calif emissions equipped trucks in those years.

 

[mr cribb]

Too bad you have a 94 model.

I have to good used computers. One from a 91 4x4 and a 92 2wd both 5 speeds.

The difference is these computers only have one oxygen sensor, and no egr or other emissions programming.

 

[01momogti]

Any difference in the timing curve would be programmed into the given that it's an electronic ignition.

91 and 92 had different camshafts between manual and automatic. 93 and 94 have the same camshaft between manual and automatic. There are different camshafts for federal emissions vs. Calif emissions equipped trucks in those years.

Is there a way to tell if it is federal or California emissions by looking at it or would I need to run a Vin check on it to find out? I thought there was a sticker under the hood that says either way but I cannot locate one on mine.