Symptoms of a bad Quarterhorse battery

jdsgallops

Registered User
Now that one car is running well it is time to get my 90 Sc running again. About a year ago I put a new engine in it I bought from Matt Haub(Dr. Fishbone). Once installed it ran great for about a tank of gas. Then I had an issue( don't remember what at this point I time). Fixed that and ran about a tank of gas through it and yet another issue. Always seemed to get about a tank of gas through it before another problem arose. Finally I barely made it home one night. I needed to keep it in boost just to get the car home. By the time I pulled in the driveway it was idling very roughly about 400 rpm. I pulled it in the garage the next morning and from that point on it would not restart. I borrowed a DIS module from Mike Inch(Bumpskier45) and got the same no start condition. Today I decided to put the trickle charger on it to have the car ready for when I had some time in the next few weeks. Battery appeared to be pretty well charged so I decided to pull the chip and see if it would start. Much to my surprise it did but was running very very poorly. It needed throttle to stay running but would not rev over 1000-1200 rpm. Letting go of the throttle the rpm went down slowly until the car would die.

Being that the car all of a sudden started and ran without the Quarterhorse in place is that an idication that the battery on the Quarterhorse is dead? I have another chip I bought at the same time on my Mustang and it has seen a lot more use but has given me no trouble.

I have recently had some issues with my Mustang that mimicked those of the SC. It turned out to be timing retarded too much from some widely gapped plugs. I am wondering if the knock sensor isn't the cause of my issues right now. The engine had sat for many years before I purchased and installed. Would this be a logical place to start looking?
 
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I had some weird drivability issues with my tbird at my last track day (the only place I open the car up) until I realized that my QH battery. Here's how you can easily check it since it sounds like you have the module pulled.
http://support.moates.net/quarterhorse-battery-and-resistor-check/

FWIW Their customer service is fantastic and they had no issues a) replacing the soldered in battery with a socket to allow for future replacement b) adding the necessary board modification to allow the battery to be trickle charged by the Car battery.

If you do find your battery is dead, give them a ring.
Regards,
-g
 
Wow, you've been struggling! :(

I doubt the knock sensor would cause anything like the problems you are having. From my memory, the factory tune doesn't even look at it at idle.

If you are confident that you are trying to pull the codes properly, it does sound like you may have an ECU problem.

Have you tried pulling codes with the QH unplugged? It should work either way.
 
Matt struggling is an understatement. When i say a tank of gas between issues I am not exaggerating. That is part of the reason why i had to step away from it for a while.

Now that I am back at it I need to understand a few things. Which is why i started a new thread and did not continue the old one. which at this time is the symptoms of a dying/dead Quarterhorse battery and how the knock sensor effects the engine.

The battery to try and understand why the car will start without the chip and if that is causing the drive-ability issues.

And the knock sensor because it seems that the timing is just suddenly being retarded.

Before I solve the current problems i need to figure out how I got here.

In my research I have come to the conclusion that i need to add another ground or two. I just did this when I had the engine out of the Mustang and ran into starting problems. Quickly solved when I added two grounds back into the system. I am pretty sure I only put the battery negative post to the block in the Tbird.

So at this time I need to figure out what seems to be pulling timing for no apparent reason causing the car to run poorly. I agree it could be a bad ECU but that is not an easy check as I have no spare computer and the bolt in the wiring harness connector in the one on the car seems to be stripped making removal nearly impossible. Thus having a better understanding of how the above two questions effect things I can rule two things out gaining traction on the ECU being the issue and find a way to get it removed and a replacement in. IOW process of elimination!
 
...... I am pretty sure I only put the battery negative post to the block in the Tbird. ....

I don't think it would cause your problems, but there should be a ground strap on the passenger side of the block too. It is a strap, not an insulated cable...it bolts to the "frame" below the airbox.
 
Took the time to pull codes today. Got code 82 and 67. 82 is there because the therm actor isn't hooked up. 67 doesn't make sense to me. This is trans/clutch sensor signal are improper or a/c is on/ improper signal. However the dashboard is lit up like a Christmas tree in KOEO configuration. Battery, up shift, check gauge, firm ride, seat belt, and CE lights are all on.

Thoughts?
 
Took the time to pull codes today. Got code 82 and 67. 82 is there because the therm actor isn't hooked up. 67 doesn't make sense to me. This is trans/clutch sensor signal are improper or a/c is on/ improper signal. However the dashboard is lit up like a Christmas tree in KOEO configuration. Battery, up shift, check gauge, firm ride, seat belt, and CE lights are all on.

Thoughts?

67 C Clutch Switch circuit failed (3.8L SC only)
82 O Supercharger By-pass Solenoid circuit failure (3.8L SC only)

Note that 82 is for the '89 SC only, where there was an electric bypass to prohibit boost in reverse.

Are you certain the grounds are _all_ healthy & intact? Pass. side motor mount to body; EEC ground at the header panel in front of the battery; EEC center bolt; no new paint on accy. brackets/heads...
 
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Iirc I did not put a passenger side ground back on. It has been a while since I have been under the car so I am not 100% positive on that. I believe it is battery ground to block, and battery ground to radiator core support only at this time. With all the grounding issues I have had in the past on my cars I should know better than to leave one off. Unfortunately time, money and not wanting to make another trip to the parts store usually have a big influence on just getting it done. Only for me to have to do it over. That said in the past when I have had ground issues the car has either run or not run. It has been my experience that if you do not have the proper grounds that the car will FINDING a ground and use it for everything. I once lost a MSD Digital 6+ box, computer, and Tweecer on my Cobra because the car tried to ground everything through the computer ground. And then the $700 shop bill on top of it. That was a no start condition though and it took weeks for the shop to figure it out, and it wasn't until they took the time to use the break out box did they find it. So as much as I agree it could be the ground I think it is only part of the problem at best.

Up shift light on means no signal from the cam sensor correct? With that and the weird codes would that point to the computer not getting a proper signal through?
 
It has been my experience that if you do not have the proper grounds that the car will FINDING a ground and use it for everything.

Beat me to it, and that's the one that gives me nightmares... Ford loves to make/break connections via ground.

Good luck.

Ken
 
Turn the key to run, reload your tune to the quarterhorse. Start it up, If it starts and runs good, the quarterhorse battery is your problem. If you turn the key to run prior to starting and your fan kicks on, that means your tune is erased. If the QH battery is failing, it is possible that the car will start but run poorly, which reloading the tune will solve.

Chris
 
Turn the key to run, reload your tune to the quarterhorse. Start it up, If it starts and runs good, the quarterhorse battery is your problem. If you turn the key to run prior to starting and your fan kicks on, that means your tune is erased. If the QH battery is failing, it is possible that the car will start but run poorly, which reloading the tune will solve.

Chris

That's a great idea!

I had wondered if that would work at one point.
 
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