[terkaa]

Hi,

Could someone post few pics of 1991 2.5 MPFI Engine? I would like to see intake manifold and thermostat housing. I have installed Megasquirt to my 1987 2.5 HSC(my megasquirt test vehicle). I am trying to get best possible MPG and learn about electronic engine controls at same time. Next step in this project is to get fully sequential injection instead of CFI and also Coil on plug ignition. But for sequential injection I need to find intake manifold from 1991 taurus or make a custom on my own. So help is needed I have browsed web to see a pic of 1991 2.5 engine but had no luck.


Tero

 

[JW657]

Perhaps this might help:

Engines | Taurus/Sable Encyclopedia

I don't know what year it is. These cars are rare with a 4 banger.

 

[terkaa]

Nope that is a CFI as mine is.

 

[Jeff K]

Look for pics of a 88+ 2.3 HSC in a Tempo / Topaz. Those went MPFI in 88, and the intakes are virtually the same as the 2.5 HSC.

 

[terkaa]

I am afraid taurus intake is very different from Tempo. First of all intake port shape is different(see attached pics). And also since there is no plenum gasket available for 1991 taurus I believe it is single piece cast not two piece as in tempo. Also taurus has "two level" intake that has coolant passages in lower level to keep intake warm and also heater core coolant flows through intake to core.


http://i170.photobucket.com/albums/u243/terokaarlela/taurus/taurus91.jpg

http://i170.photobucket.com/albums/u243/terokaarlela/taurus/tempo91.jpg

 

[PerformanceWithEconomy]

Terkaa: We are in a similar predicament. I too am looking for info on the 1991 2.5L motors that were supposedly installed in these cars. Like you, I can find NO info on this motor other than the small amount that Ford initially released in print. NOBODY on this site seems to be familiar with this combo either. On top of that, this motor is not even listed as being available in the 1991 cars according to Hollander ( Junkyard parts interchange & pricing guide ) from what i've been able to find out. It is almost like it never existed.

As such, PLEASE keep me informed of ANY info that you find out about this subject and i'll do the same. I already have a thread running on this very subject.

http://www.taurusclub.com/forum/87-engine-drivetrain/162048-any-info-2-5l-motors-1991-a.html

Outside of that, i was unaware that the Taurus kept the older design CFI units until 1990. At least, that's what the "Engines" link above states. The similarly designed 2.3 HSC motors in the Tempo / Topaz switched from CFI to SPFI in 1988 and then to MPFI in 1992. This puts the the Taurus HSC motor 3 years behind that of the Tempo in terms of development. All of this time i kind of "assumed" that the Taurus was already running MPFI and had upgraded to SPFI in 1991. As such, this bit of info has helped me somewhat. In this respect, the Tempo HSC motors were more advanced and i've been looking for something that didn't really exist. This brings me back to square one.

I am VERY interested in your experiences with the Megasquirt system as used on your 2.5L motor. When you get the time, can you please drop me a line with some of your notes / observations on this subject? I would greatly appreciate it. Sean
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[terkaa]

Hi,

I am also thinking that 1991 MPFI is only a legend that never really existed. My plan is to fit intake manifold from 92 tempo to taurus. This requires at least some grinding on tempo intake to fit ports to taurus head. Also thermostat housing from Tempo must be fitted to have outlet for heater core. I have tune file for megatune if you need it. It is all stock taurus 2.5 CFI but it has been setup for Innovate LC-1 wideband lambda. You can download megatune for free to view settings etc. It is not perfect tune but it is sure enough to get engine running and drive. It is for Megasuirt II running microsquirt 2,89 code. Next step for me is to step to MS-extra code(I need it to get closed loop idle control instead of warmup only and also to use COPS and sequential injection)

Tero

 

[PerformanceWithEconomy]

Due to the amount of mods and cam duration that i'll have in this motor, i'm definitely going to have to do some type of custom tune on the ECU. If you want a simple upgrade, you can install the HSO cam into your motor. The difference in performance will be VERY noticeable with no measurable loss in bottom end and midrange torque. I've got a much longer duration / much higher lift cam that i had custom ground for mine. Combined with the roller rockers that i've got coming, it should run pretty darn good. Sean
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[terkaa]

Hmmm according to service manual and TempoTopaz.com :: Tempo Topaz Car Club of North America 2.5 HSC's are originally equipped with 2.3 HSO cam. I am not looking for performance I am aiming for economy and also E85 fuel possibility.


Tero

 

[PerformanceWithEconomy]

I've seen conflicting reports / part numbers for the stock 2.5L cams. If they use the standard 2.3L HSC cam, it is an absolute dog and designed for VERY low end torque and very high levels of cylinder pressure. The HSO cam will definitely make more power, but it will do so at the expense of lower net cylinder pressures with reduced mpg's. Bare in mind that the HSO cam would NOT be compatible with Ford's SPFI system but will work fine with the MPFI system.

As far as E85 goes, i've been running a blend of E85 and E10 in my car for several years now. For sake of clarity, i do have a 1994 2.3L HSC motor with SPFI on it. I do not know how well earlier EFI systems will adapt to this type of fuel blend, but mine works quite well like this. More power with the same mileage has been my experience. Sean
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[PerformanceWithEconomy]

The gasket set that you show for the 2.3 is the HSO set, not the HSC. Same basic motor with a different cylinder head. The heads are interchangeable so long as you use the correct gasket set, so either would also work on the 2.5L motor too. Sean
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