Arizona 90 SC needs some help...

arizona90

Registered User
Hello Guys... I've been reading a lot on this site in order to enjoy my newish 90 SC a bit better, but... I just replaced the wires and plugs, plus PCV, and it still bogs down between 2,800 and 3,300 to the point that I then back off and shift. The cars history is its from California, hasn't had tags on it since 1998. It shows 76,500 miles, and by the looks of the body and interior, as well as the engine bay, that is actual mileage. It sat so long that when I drove it home to Arizona from Mira Loma, that I didn't think I was going to make the last 50 miles (the fuel filter just about imploded on itself). Easy and slow got me home where I changed the fuel filter and it then would run, just not over 2,500 rpm then. I have noticed that when its cold, it will accellerate to 3,000 with no problem, then begin to bog. As it get hotter, it then starts to bog down between 2,500 to 3,000 and really won't run over 2,800. As its a 5 speed, shifting gets me along but i would really like to feel the whole potential of this motor. The oil pressure is good, it doesn't overheat, it just doesn't run out well. Noticed that the plugs looked like they were a rusty color, all of them. As far as the rusty color of the plugs, I thought they may be the result of the prior owner using an octane booster and then the car just sitting still for years. There don't seem to be any vacuum leaks, at least not what I can find. I'm thinking that either the cats are clogged or the coil doesn't deliver when it gets hot. Now I'm interested in your thoughts. I'm willing to try anything you suggest as I intend to keep this car for 5 to 10 years and learn as much as I can about it. I really enjoy driving it. I also bought the last right hand rear electronic shock (motocraft) that Rock Auto had and am looking for another one for the left side (they seem to be A & B - B is the right side). All your thoughts will be greatly appreciated. My prior wrenching experience with cars was racing a Toyota Corolla SCCA ITC car in Phoenix in 2004 where I enjoyed winning eight races in a row and the road race championship in my class. Then again, that was a simple toyota, not an SC. Looking forward to hearing from you.
 
You should check the fuel pressure and think about changing the filter again. Check the codes too - if you don't know how, see if a local auto parts store can do it for you.

Shocks aren't A or B - good luck finding another new one right now. Inventory is zero with no firm word on when/if that will change.
 
Arizona90 codes with a strange one...

Had the local Ford dealer read the codes on my 90 sc today and he came back with...

(72) Insufficient MAF change
(73) Insufficient MAP charg
(25) Knock sensor circuit
and the last one he didn't record as a number but said it was showing the PCM code for an automatic, not the 5 speed I have.

Now I'm wondering if someone changed out the PCM with an automatic one and that's what is stopping me from being able to go over 3,000 rpm?

Any heip here will be greatly appreciated.

Marty
 
72 R Insufficient Mass Air Flow change during Dynamic Response Test
73 R Insufficient Throttle Position output during Dynamic Response Test
25 R Knock sensor not sensed during Dynamic Response Test

Those are most likely related to not being able to rev past 3k. There can be any number or reasons for that, from a seriously plugged air filter to bad plugs, etc. Did the dealer have any opinion on why that is happening? Did they check the fuel pressure? Are the cats plugged?

If you're not confident about the EEC, you'll need to take a look at it and see what the numbers are.
 
Arizona90 codes and wrong EEC?

72 R Insufficient Mass Air Flow change during Dynamic Response Test
73 R Insufficient Throttle Position output during Dynamic Response Test
25 R Knock sensor not sensed during Dynamic Response Test

Those are most likely related to not being able to rev past 3k. There can be any number or reasons for that, from a seriously plugged air filter to bad plugs, etc. Did the dealer have any opinion on why that is happening? Did they check the fuel pressure? Are the cats plugged?

If you're not confident about the EEC, you'll need to take a look at it and see what the numbers are.

Thanks for the quick response. The air filter, plugs, wires and fuel filter are all new within the last two weeks. Dealer didn't check the fuel pressure. I'll try to get the car up on a lift this weekend so I can check the cats. As I live in Prescott, AZ, I can do without the cats... any suggestion where I can get replacement pipes to eliminate them?. I'll try to get the numbers off the EEC in a day or two. Marty
 
When you say "bog" ... what do you mean? Does the power cut out and then back in, in surges or jerks? Or does the power just go soft? What does it do exactly?

At the Ford dealer ... How old was the guy who actually tested the car? I just want to be sure that the guy actually DID the dynamic response test. A young guy who hasn't worked on anything older than 1996 may not have any clue how to do the test. And what are the chances that he actually tapped on the engine block with a hammer during the test?
 
When you say "bog" ... what do you mean? Does the power cut out and then back in, in surges or jerks? Or does the power just go soft? What does it do exactly?

At the Ford dealer ... How old was the guy who actually tested the car? I just want to be sure that the guy actually DID the dynamic response test. A young guy who hasn't worked on anything older than 1996 may not have any clue how to do the test. And what are the chances that he actually tapped on the engine block with a hammer during the test?

The guy at the dealer looked to be early thirties or younger. The power goes flat, in other words its like an ignition failure, where you can't go any higher no matter what you do. When I get there I usually have to shift to a higher gear to continue on. It doesn't surge, it initially seems to jerk (not violently) but then no further rpm response. If I stay at where it starts to go flat, it will stumble but no more than 2 or 300 rpm more can be had at most. Don't know about the hammer test... that's all I have. I can drive the car anywhere, as long as I stay under 2500 to 3000 rpm. Its smooth and accelerates fine to that point. I can run on the highway at 70+ in fifth gear with cruise control on with no problem. Marty

Just found this on AllData - "{49} Certain M/T models with calibration code 9-15A-R12 may require exhaust system catalyst & PCM replacement. Source: Ford Motor Co. Emissions Recall 93E44." This may be the problem. What do I do now? I'm sure its too old to be under any kind of warranty. Suggestions? Marty

Ok.... just checked the car and it had a sticker on the drivers side fenderwell saying this recall had been done... still need help. Marty
 
Last edited:
EEC Location?

Is there an easy way to find out what my EEC info is? Or do I have to unstuff all the wiring tucked into the passenger side footwell. The EEC seems to be loosely placed in the upper well area. Not fixed but moving around in there. Any ideas? Marty
 
Unstuff it and check the labels:
m8NMc34LtFte6VVdFWjltyw.jpg


If you tilt the glove box all the way down/open, you should see a grey box (w/one bolt?) held in place with a white plastic frame sitting vertical on the right side (behind a cover, usually). The main harness comes in from the bottom and is held in place by a center bolt.

You need to remove the black side kick-panel to get at the EEC. It can be a bit of a puzzle to get all the way out so be prepared to spend some time and effort, but if it is loose in there and the cover is already out, you might be able to see at least one of the tags.
 
Last edited:
Okay, thanks for the additional information.

I think, from your description, that either the engine isn't getting enough fuel, or that the ignition is cutting out at higher RPMs. The very first thing I would do is test fuel pressure. If you can't borrow a kit, buy one from Harbor Freight. It's like $25 and works great. You can even run the gauge to the base of the windshield and check it while driving. (Better to have an assistant check it, of course. And don't go fast if the hood isn't fully latched! But I am sure you know that.)

Fuel pressure should be 39 psi higher than atmospheric with key on and engine off. While idling, it should read somewhere between 28 and 32 psi over atmospheric. (Engine vacuum reduces the absolute pressure, while the fuel pressure regulator maintains the pressure differential across the injector at 39 psi.) Under boost, it should gain 1 psi of pressure for every 1 psi of boost. So at 5 psi of boost, it should read 44 psi.

You might also have a MAF problem, such as excessive dirt on the sensor wire, preventing it from reading properly at higher RPMs (higher airflow values). If you have a multimeter, you can actually check that while driving as well. You just need some long hat pins to backprobe the connector, a length of lamp cord, and 4 insulated alligator clips. Clip to the pins and the multimeter probes, run the lamp cord out the hood and in through the door opening, set meter to DC V, and drive. It should range from 0.8 V or so at idle to ... well, if you could go WOT and reach high RPMs, it would be in the mid- to high-4s, but your car won't reach that in its state. But if it levels off while RPMs climb, that is a clue that it may be reading improperly. Of course it will level off when RPM does, but if it levels off first, that is your clue. Again, assistant may come in real handy here.

If the problem is ignition related, it's usually fine and then suddenly NOT FINE, as in major jerking, cutting out, engine dying. I guess you might have something like a poor ground path causing a weak spark voltage that might have a "softer" failure mode. The coils themselves very rarely go bad. The DIS (distributor-less ignition modules) often do go bad, but those are usually very hard, erratic failures.

As for the EEC, it should definitely not be loosely tucked anywhere. In its stock form, it is quite a pain to remove. It seems very likely that it was replaced at one point, by a dealer or someone else, and not properly replaced. I wonder if the loose mounting could cause its own set of problems? Harness plug connection working loose, perhaps?
 
Last edited:
Have you verified the throttle is opening all the way when the pedal is pressed to the floor?
 
Arizona 90 - codes for eec seem strange

Here are the numbers I found on the EEC which was a reman by ford and sealed with their sticker.

Ford: F0PP12A65OALA and E9AF14A624AA

I got nothing for the first number and the second seems to be for an 89 Mustang Automatic.

Any ideas?
 
Here are the numbers I found on the EEC which was a reman by ford and sealed with their sticker.

Ford: F0PP12A65OALA and E9AF14A624AA

I found, but didn't verify these for 'E9AF14A624AA':

87-95 5.0L Mustang
DA1 A9L A9M A9P A9S A9T A3M A3M1 C3W C3W1 X3Z 8LD T4M0 W4H0 U4P0 J4J1

84-85 SVO 2.3L Turbo Mustang
PE PK PK1 PF2 PF3

96-2003 4.6L Mustang & Cobra
- Too many to list

94-2001 3.8L Mustang
- Too many to list

2003 Mach I
ZYA2

1988-87, 1996-97 Tbirds
LA3 LA2 8AU FTE1

93-95 Lightning
C3P1 C3P2 C3P3 AKC0 VEX1

1999-2000 Lightning
CUX1 CUX2

89-95 SHO Taurus
X2J D4U1

1989 Lincoln Mark VII
D9S

1999 SVT Contour
XGT1

1995-1996 F Series & Econoline
ZJT0 CHC0 MZH0 AHA0 PLC0 RRE0 COD2 WED3 EVE3 FQP0 HZL0 YER2 FEZ3 VUE3
LEM4 WGG0 WAS3 PUG4 SOX4 DPP0 FFX0 TAT4 GLU3 TYY0 GMA

Seen this thread?
http://www.sccoa.com/forums/showthread.php?48354-EEC-Cross-reference&highlight=eec+code
 
Arizona 90 - F0PF-12a-650-ala is this for a manual trans?

I must have misread the number and now believe the number to be F0PF12a650ALA and was part of the calibration code 9-15a-r12 recall where both the EEC and the Catalytic convertors were both replaced at the same time for California 1990 supercoupes with 5 speeds. I'm trying to see if there were any problems with these EEC's where it would not allow my car to go over 3,000 rpm without loosing all its power. Marty
 
The Ford Dealer says its the right EEC and some more thoughts...

The dealer checked their books and said my EEC is the correct one for my 5 speed car. On the way to the dealer, five miles away, as I started getting onto the highway, the car accellerated to 4,000 in second, then flattened out at 3,600 in third and by then I was over the speed limit so I backed it down, then would slow down and accellerate again, it then flattening out closer to 3,400 etc. The dealer checked my numbers and said it was the correct EEC. On the way home, I then tried going through the gears again, but now that the car was warm, it would flatten out at 3,000, at which point I would shift again. When I parked the car in my garage, before I shut it off, I ran it up to 4,000, then tried to repeat it but it stumbled, or kind of had what I would call a 3,500 then 3,000 rev limiter effect. Upon shutting it off I wondered if what my problem was the coil getting hot. This problem always occurs when the car gets warm, and so far, it has never gotten hot or over halfway on the temp gauge. Of course its also been cool lately so its not seen any weather over 70 degrees. What else should I check and do you think the coil could be the problem? If you do, what kind should I replace it with? A Ford part or maybe an ACCEL coil or? I have had my mechanic check the fuel pressure and he says its within specs, on the lower side. He also said the when he replaced the spark plugs and wires that he reved it to 5,000 rpm with no problem. He did that in his shop and not on the road. He did notice the flattening out of power at the 3,000 rpm mark when he took it for a drive but couldn't figure it out and had to go onto other things. Marty
 
Fault Codes Ford Dealer came up with...

The dealer came up with...
(72) Insufficient MAF change
(73) Insuffieient MAP change
(25) Knock Sensor circuit

Marty
 
And the dealer said it was showing that it was an auto trans, not standard.

This fact that as the dealer was pulling the codes, it showed that the car was an auto not a standard, was my reason for pulling the EEC out to check out the numbers. I then ran the numbers by the same dealer and they came back that it was indeed the correct EEC for the car. Now I don't know wether I should try another EEC that is for a 5 speed and compare the differences. It seems that I am about to start throwing things at the car in order to find out what is causing the power loss. I'd rather do it smarter than kitchen sink it. Any help here will be really appreciated. Marty
 
Those codes could simply be the result of a failure to sufficiently goose the throttle during the KOER test. If that wasn't the case, then they could maybe point to a blocked air filter/intake, contaminated/failing MAF and/or plugged cats.

Since you said it recently had plugs/wires installed, something you can do that hopefully won't require throwing parts at it would be to verify the plug firing order. See this thread: http://www.sccoa.com/forums/showthread.php?89549-firing-order&highlight=firing+order

As for the EEC, why not work to positively know you have the right unit, and then effort any issues from there. Auto parts stores or Rock Auto will sell you another based on your model....looks to cost around $100.
 
EEC and Cats Check this coming week...

I'll find a new EEC and have the cats checked this week. My mechanic said that the MAF was fine, and that he cleaned it when he put the wires and plugs in. The guy I have working on my car is a 20 year former chicago mechanic who relocated to Arizona. Seems to be saavy and I was turned on to him by a Thunderbird owner (94 - V8) that was very pleased with his work over the past several years. I'll keep going on this and appreciate everyone that is helping. Marty
 
Back
Top