View Full Version : Same problem as Manny, but still not fixed...

11-14-2005, 12:54 PM
Since last winter, I have had the same problem as manny. The car wants to "jolt" sometimes under acceleration like it is hitting off time or something. Sometimes, it won't even start. When I go to crank it over, it "conks" out, like the engine is firing prematurely and kicking backwards, but sometimes it will fire right up no problems. Basically it has been doing this ever since I replaced the HB last winter. I replaced the crank sensor at the same time and used the proper magnetic spacer to set the gap on installation. When I went to fire it up and pull out of the shop, it conked out until the computer read #1 cylinder, then it knew when to fire correctly. I ended up replacing the cam sensor also and still no better. Finally, I paid $160.00 CDN and picked up a new DIS module. The old Motorcraft one tested bad for high rpms at Part Source so figured I would try the new one. Unfortunately, the new one would not even start the engine. It would only keep conking out and conking out and would not get even a full crank in before it prefired again. I switched back to the Motorcraft one so now I can still at least drive the car. Tried to pull the codes with Ford Rotunda computer, none came up, not even a PIP (crank) sensor signal or nothing. At that point we left it be until I get the car in the shop this winter (again...). Once the car is started, it runs fine until sometimes on accelerations, it will "jolt" for a split second or so but not actually stall out. Recently, I have had problems with high idling but that has cured itself just last week. Dad figured some air was getting in on the engine side of the MAF sensor, so the computer couldn't figure out how much gas to put in to compensate. The car is a 1990 5-speed SC and I just rebuilt the motor last fall. The tach does nothing, or at least nothing I can notice, when the car acts up, nor does the upshift light do anything unless I actually stall right out. I wish I could just get everything working on it normally again.

One more thing, any recommendations on winter tires for these cars. I have to find some 16" steel rims from a wrecker or somewhere. Once I can afford some nicer wheels for my car, I plan to use the stock rims in the winter. I was looking at the new Nokian RSI series but they don't make 205/65/R16 size. I want to go to a 65 over a 60 side wall just for some better clearance, but I will have to watch my speed I guess. Any suggestions?


David Neibert
11-14-2005, 01:16 PM
Since all your troubles began when installing the new HB, I would suspect the crank sensor. Check the sensor ring also.


11-14-2005, 01:20 PM
Will do, hopefully it is something down there somewhere. I don't exactly feel like ripping apart the harness to check for cracked or broken, or bridged wires. The computer tested good according to the Rotunda, so there shouldn't be any wiring problems, hopefully.

11-14-2005, 02:05 PM
Sounds like the cam sensor; you'll have a hard time starting the car when that sensor isn't calibrated right. Did you get the proper tool and align it 30 deg clockwise from the front of the engine? There are a bunch of good threads on the subject here. Best of Luck

David Neibert
11-14-2005, 02:09 PM
A couple questions.

Did you use loctite on the four bolts that attach the sensor ring to the back of the balancer ? Did you have any difficilty installing the sensor ring on the new balancer, such as bolt alignment ?

Did you check to make sure that the crank sensor had proper clearance from the sensor ring on both sides of the sensor ? Did you rotate the engine and recheck the clearance.

I don't think there is a problem with the wiring, I think that your sensor is damaged from contact with the sensor ring or it's a defective sensor.


11-14-2005, 05:06 PM
We inspected the ring for defects before installing the HB. It was a used HB from a parts dealer here in Regina. We did not do anything to the ring as far as adjustment goes. We just used the magnetic clearance strip to set the gap on the sensor and being there was no interference with the ring when the engine turned, we figured she was good to go.

When I get the car up in the shop later on I will check it out. To me this has to be the problem because it is the only place we were fooling around with at the time I changed the HB. By the way, is there really a HB out there that is better than the factory one, or should I stick with the factory. I just don't want to undergo the process of pulling the broken chunk out of the front cover again like the last time the HB broke. I still had a six month warranty on the original one I got but this other one I have now, I am still weary of its condition being I did also get it used, and also with the six month warranty.

David Neibert
11-14-2005, 07:17 PM
Installing the used balancer is likely at the root of your problems.

Dave Dalke (XR7 Dave) is working with another company to produce a more resonably priced balancer for SCs. Until then, your only alternative is buying a BHJ. They are very nice units that are far better than the Ford balancer, but IMO they are way overpriced.


11-14-2005, 09:15 PM
This sounds just like the probblem I had last year. The car ran great, then it set for a few months and then it was hard to start, and the colder it was out the harder it got to start. But once it was running you was good to go and yes it would surge sometimes mostly going up hills. The car had a new tune up less then a few hundred miles before the problem started (plugs, wires, fuel filter, ect.) I banged my head for weeks switching parts with my running car, pulling codes, you name it. Then I decided to try plugs and I could kick myself in the a$$ when I found out I had 2 filed plugs. Only thing I could think filed them was old gas? Any how car is still running great.

11-15-2005, 01:45 AM
I'll check the sensor and HB first, the car was not sitting long when I did the HB, and any old gas that may have been in it when I first bought the car would have been well used by then. Where would I be able to pick up a cheap HBJ (if there is any) and have it shipped to Regina, Saskatchewan, Canada.

Question, when we were torquing down the HB, it really seemed it was going on harder than the first one did when I had the engine out of the car doing the rebuild. Could it be possible the keyway could be off. To me if that was a factor, it would not go on at all. I know for a fact the key stock was in place at the time we installed the HB, so as long as it is in the groove, everything should be good from that end right? Also, if the keyway was off, the car wouldn't run at all. It is really funny because it only acts up when starting the engine and once in a while when accelerating both hard and when cruising to a higher speed without shifting down to 4th. Other than that, the car itself runs with no other difficulties.

Lastly, I don't think it would be a factor, and some of you may not totally agree, but I have been running the car on regular 87 octane unleaded fuel. I know it is recommended for 92 or better but since it has not yet shown signs of pinging or detonations, I figured it was pretty safe, considering they still run at a low enough compression ratio. Even when I completely run the tank low and fill it up with higher octane with added boost for racing, the car runs like it does with normal 87 fuel. Even racing on normal 87 and pushing the engine harder than normal, the car still does not ping or detonate. I came to the conclusion that fuel is not a factor in the reasoning for the timing issue.

Any other opinions would help. Cam sensor is good, and plug wires are good. I still can't figure out why a NEW DIS module still wouldn't start the car though.

11-15-2005, 04:32 AM
This is just a thought and I may be wrong, so someone else jump in and correct me if I am but...... If you are running 87 octane and it is running as good as or better than it does with premium, you could very well have a boost leak. If you DO have a boost leak you are likely running rich and this MAY have something to do with the way the car is running.

When you swapped the balancer, did you have the intercooler tubes off? If so you may not have gotten them tight and sealed properly.

I also think there may still be an issue with the balancer and/or crank sensor but you should at least check out the intercooler piping for and leaks. Check this post from the FAQ forum on "Boost leaks, what they do and how to deal with it".


That may not be the entire cause but it is worth checking into anyways.


11-15-2005, 12:59 PM
... If you are running 87 octane and it is running as good as or better than it does with premium, you could very well have a boost leak.
Just FYI.. unless its an emergency, never run 87 octane in the super coupe.. If you must, then take off the supercharger belt or at least pull the octane plug. :rolleyes:

OK, let me rephrase it.. unless you're planning on an engine overhaul in the near future, use 89 octane minimum.

11-15-2005, 01:04 PM
What is this Octane Plug I've been reading about, where is it located?

11-15-2005, 08:08 PM
I have had the intercooler tubes off and on since I did the overhaul last fall, both at the blower cap and both top and bottom of the intercooler, in order to change the water pump, which the bearing went on and made the seal leak. I did not yet check the connection to the inlet plenum on the back the one feeding the bottom of the IC. When I install the tubes, I use an orange-coloured silicone sealant of some sort on the seat of the mating surfaces, but I cannot remember the name. The Auto Meter aftermarket boost guage I put in reads a steady 10-10.5 psi on the factory pulley when a little harder throttle is given when accelerating. Vacuum stands at about 17 H-g when idling. Remember, I live in a higher elevation than most places in the states but have not yet compared to any other SC's in the area. They seem to be a fairly rare car in these parts nowadays. I don't think I am leaking any boost but I will check again with a vacuum tube guage.

Basically, as far as the 87 octane fuel goes, as long as there is no pinging or detonation in the engine when normally running, it shouldn't hurt it. Just curious, what is the difference between the SC and the GTP, how come they are blown positive displacement like these cars and can still be rated for only 87 octane? Now, I do agree it is not healthy to run, but with the way fuel prices are going, and being it has not yet caused any bad symptoms, I don't think the compression ratio is high enough yet to worry, but I will consider it. I ran the car for two months on 92 octane premium fuel and still had the same ignition problems. My guess would be the sensor or HB.

In speaking, can anyone give me a quick list of what could POSSIBLY happen from running the 87 fuel. We checked the plugs and there is no fouling or bridging, no signs of premature fire or misfire on any of them. When we did the overhaul, we used new HGs from Sealed Power which are guaranteed for the life of the car. Apparently they are one of the best ones to go with, and I do believe a pretty penny was paid in aquiring them. Other than the small potential of blowing gaskets and possibility of fouled spark plugs, on the factory engine, in my opinion, there really should be nothing to worry about.
But please, correct me if I am wrong.

Thanks for the opinions,


David Neibert
11-15-2005, 11:04 PM
Just curious, what is the difference between the SC and the GTP, how come they are blown positive displacement like these cars and can still be rated for only 87 octane?

The supercharged GTPs also require 91 octane.


01-06-2006, 10:22 AM
uhhh, ive NEVER put anything but premium fuel in my SC's (any of them......ever) and i run 91 octane minimum in the gtp, because thats what the owners manual says.

also the gtp is non intercooled, and runs less boost than the sc's. and its wrong wheel drive.

01-06-2006, 11:52 AM
I would check the fuel pressure, FPR, fuel filter, and the fuel pump. My 88TC and my 89SC both have a surging/jolting when I hit the gas or try to start them up. On the 88TC it was the fuel pump and filter. I havent had the chance to check my 89 yet...so I cannot confirm it..