EFI Distributosr T2T52371 vs T2T52371B

[i218127]

71 vs 71B

Not sure what's happening today, but I've posted twice and been kicked off by redirection both times. Here goes again:

Pulled my unit to-day. My 1992 distributor was a T2T532371 optical drive unit with the .475 cam shaft. The "O" ring that mates it to the engine was hard as a brick and leaking oil. The inside showed a coat of oil and some grit. The top shaft was tight, but the engine side shaft was wobbly. My timing must have varied quite a bit.

Called O'Reilly Auto parts. They have a unit in the warehouse and could get it to me by 4:30PM. Price: $173.00 plus $30.00 core charge. The unit is a rebuild by CARDONE (?) with a lifetime warranty. Will pick it up tomarrow and install it next week. Post more later.

[sketchman]

So you're saying the 71 is for the EFI Festiva and the 71B is for the Aspire?

EDIT: Never mind. Just went and looked at rockauto. It lists 3 different dists all for the 90-93 Festiva. 71 / .475, 71B / .475, and 71B / .526.

EDIT AGAIN: I see.

[i218127]

I worked with Rock Auto too and saw the same thing you saw. What I think happened is: most, and I think that means 60 to 70% or better, 90-93 Festiva have the 71 Optical Drive unit. I understand for Festiva VIN "H" built before I think February 1993 probable used the .475 cam. So, more often than not, these units are Optical.

I can say only that this is more often that not. At the O'Reilly store, they push you to the .475 rotor for 1992.

The build date on my 1992 is December 1992. I know that my unit came with the Optical Drive AND the .475 rotor. In about early 1993, Festiva went to the bigger camshaft on VIN "H" engines. I know this because I searched for a replacement engine and the first thing they asked was what was the build date of my car. This was done to determine the cam size and the suitability of using my existing parts on the new engine.

This may not clear up the confusion between 71, 71B (Hall effect), .475 and .525, but it seems logical that as Mazda changed to the bigger camshaft, they had 71's with .475 rotors left over. I suspect they just adjusted to the new cam on the fly and kept on going. A rolling changeover like Mercedes does. (Old Mercedes require a chassis and an engine number to buy parts because they ROLL IN changes as the year goes by.

Changing Distributors is not a quick and easy job on our car. Physical replacement is easy....getting the right part requires that the old unit be removed and checked. I see no other way to do it !! I think with 246,000 miles on the old unit, replacing it is the only thing to do. I hope the performance results will justify the work and expense.

[i218127]

71 vs 71B

Picked up my rebuilt distributor today. It's a A-1 Cardone unit part number 31-38400. As you'd expect, it's clean and tight. Will try to put it in next Tuesday. (Medical commitments prevent earlier installation.) Will post results.

[i218127]

Put in the new distributor today, but ran into a real problem. The crankshaft pulley assembly doesn't have any timing marks on it ! I put my 92 pulley on and it shows 10 degrees. Sounds slow, runs bad. No guts. Advanced the timing by eye and ear, and it sounds and runs better. Not right... but better. Question...is the crankshaft pulley on the 90 EFI engine different than the 92 ??? So far, it looks like about 5 degrees off, (slower) with the 92 pulley. And...how do you time a 90 EFI engine. Some books say ground a specific terminal and check timing/adjust idle. Others just say just adjust idle to 750 rpms. I've also been told that the 90 crankshaft pulley has a notch in it for timing purposes. Need help !! Engine runs good, but want it to run great and correct !!

[TominMO]

If your build date is Dec 1992, then it is a 93 model year vehicle.

In MY93 (and late 92?) they had the big-nose cranks, so maybe there is a change in how the pulley timing marks were done between the small-nose pulleys and the big-nose ones.

[1990new]

This is an interesting link. Crate engines for Festiva. Shows variation in crank snout sizes and lifter, rocker etc.

http://www.chsmachine.com/engines/html/ford_engines.html

To answer the question about timing marks.

I checked my pulleys, I have two main pulleys and 1 AC pulleys, the main pulleys have 2 marks. The 10 degrees before TDC is white on both pulleys and is slightly counter clockwise of the keyway knotch. The TDC marks have no paint in them. All pulleys have 27mm holes. I also have 2 timing belt sprockets. One has a 22 mm diameter hole and the other has a 27 mm diameter hole. Have 2 27mm pulley spacers too.

Make sure you look for the marks on the main pulley (rear). There are no marks on the AC pulley.

[TominMO]

Oooh, good point. I was assuming he was looking at the correct pulley.

[i218127]

Beginning to understand what's going on. The '92 CRANKSHAFT can have two (2) pulleys bolted to it. The one on the outside (closest to the passengers side fender) runs accessories such as Power Steering and A/C. This is per the 92 service manual. The inside pulley (the one next to the engine) runs the Water Pump and the Alternator.

Per the book, the timing marks are located on the inside crankshaft pulley. This inside pulley should have a Yellow Mark that indicates TDC and a White Mark that indicates 10 degrees Before TDC. Timing should be set to 10 Degrees Before TDC at normal operating temperature and about 680-720 RPM Computer Control grounded. Also, there seems to be spacers between the two pulley setup and a spacer between the inner pulley and the engine. Looking at another thread, the whole setup is timed to the Crankshaft/Camshaft timing belt relationship. If the Camshaft belt is off, the whole shooting match is off. (I know this is obvious, but since I didn't put on the camshaft timing belt I could only assume that the belt I have was installed correctly...it ran !!)

As stated in the other thread I can time my engine based on vacuum readings, (as close to 22hg as possible) or I could take the thing apart and check the Camshaft timing belt for TDC. Since I'm lazy, I'll try the vacuum readings first (a no cost option). Will then check how far the 92 pulley is off it's timing mark. This should give a good indication as to how far, if any, the camshaft belt is off. Comments???

[i218127]

Oh !! Thanks 1990NEW!!!!