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2.3 Litre 4 cylinder Mustang

I’ve recently purchased a 1987 Mustang LX with a 2.3 Liter 4 cylinder and 5 speed manual tranny. The car runs and drives well, no smoke and the trans shifts fine in all gears. However, the engine idles at about 2000 and when the clutch is depressed, the idle goes up (all by itself) to about 2600! The previous owner (dpo?) said that the car originally had a six cylinder but the head was cracked, so he installed the 4. Could the 6 cylinder e.c.i. computer be still installed and causing this? If so, how do you tell the difference in computer modules?

It could be true. Take yours out and compare it to one in the junkyard and see if the numbers match, or the connectors. Check with a Ford dealerand see if your computer is the one that was specified for your V-6 model car.

I think someone has their information crossed up. I’m about 99%+ certain the 87 Mustangs were never offered with a 6 cylinder. It was either the 2.3 or the 5.0 V-8.

Look at the 5th figure in the VIN. If it was a 5.0 car it should have an “F”. The cars with the 2.3 should have a “Y, T, or A” depending on Fed., CA., etc.

A high idle could be caused by a dirty/faulty Idle Air Valve. Cleaning may help and it’s easy to do.
Other possible causes could be a hanging throttle cable, air leak, ignition timing advanced too much, or a hanging transmission throttle cable. I think this year model still used the transmission cable.

If this was a V-8 car converted to a 4 banger (why???) all bets are off.

Let me add my vote with OK4450 - I don’t think these cars came with 6 cyl. I have a 1993 with a 2.3 and a 5 speed. Great little cars and very fuel efficient.

I would suspect the ECU. I’m on my 3rd one - of course, I’m approaching 200,000 milea and I bought the car with 100,000 miles.

You are correct sir. The V6 option disapeared in 1986 I think. Having a 4 cylinder Mustang is like running a marathon in combat boots ; sure you can do it, but why would you want to?

Yep, no 6 offered in '87. And the previous 6 wasn’t a V6, it was the venerable 200 CID straight 6.

I believe the 3.3L I6 was discontiuned in 1983 in favor of the the 3.8L V6.

Oops! You are quite right. The 3.3 I6 was finally retired in '83.

My brother owned one of these Pinto’s…I mean Mustang.

What a piece-of-crap car that was. It was by far the WORSE car I ever drove or worked on (and I was CONSTANTLY working on it). After 50k miles the car was almost junk.

Took Ford a while but they learned their lesson…IMHO the new Mustang is the sharpest looking car on the road today (that most of us mere mortals can afford). I tried to talk him into buying of those…but he’s so turned off by Ford for his last 3 Mustangs…I don’t think he’ll ever buy another Ford again.

I’m just going to support what everyone else has already said-there was no six cylinder engine in 1987. I suspect that there could be a problem with the IAC valve, which you could remove and clean, or replace. Also make sure that the throttle body plate is closing all the way and there’s no hang up in the throttle.

You’re thinking of the horrid Mustang II of the mid-70s. The car in question here is a Fox-platform version, not Pinto-based.

No I’m not…Brother owned a 83 Mustang with the 2.3L…same engine as the Pinto…And about the same size…and as poorly made.

I don’t know how reliable that vintage Mustang was in other departments, but that “Pinto engine” was a very good design and generally thought of as very reliable in the Pinto and many other models. A lot of you seem to be forgetting the The turboed version of it did really well in the SVO Mustang (intercooled), Mustang turbo GT, T-Bird Turbocoupe, Merkur and others (not intercooled). That means that 4 cyl 'stangs were built between '83 and 86, but they had power-adders. No army boots there!

This vintage of Mustang is not a bad car at all, no matter what engine it has. Both the 2.3 and the 5.0 are reliable and time-proven.

These are also some of the most beat upon cars ever put on the face of the earth and most problems are going to be traced back to the flogging they receive; or the lack of maintenance.
(Example: the T-5 transmission. It’s claimed that the trans is “weak, won’t hold up, and of bad design”. Not. The transmission is fine IF not abused. Hard to believe someone with a GT with the 5.0/T-5 would beat on one, huh? Start modding that motor and the trans whipping becomes even worse.)

but that “Pinto engine” was a very good design and generally thought of as very reliable in the Pinto and many other models.

The Pinto engine may have been fine…but the rest of the car was a piece of crap. If you were LUCKY enough NOT to blow up…the car was junk LONG BEFORE 100k miles. Even with the Chevy Vega’s problems…the Pinto was about as reliable.