JMS Chip and 94/95 computer

moponys · 09-24-2001, 11:44 AM

I have a 94 5.0 with a JMS custom chip in it. For the first three weeks after it was installed, the car ran great (better than ever) But just after that, it started to ping again at part throttle. I could figure it out and started thinking I was experiencing another problem. As an experiment, I reset the car's computer by disconnecting the battery for 30 minutes. After that, the part throttle pinging was gone again and the car, again runs great with no pinging what so ever.

Is it possible for the computer to learn around the chip after a short period of time???

Please, any help would be greatly appreciated.

------------------
TFS twisted wedge heads, TFS street intake, Lunati cam .500/.510 218/226, BBK FPR, BBK shorties, BBK 70mm tb, Pro-m 75mm, ASP pulleys, FMS 3:73, Transgo shiftkit,Flowmasters, Bassani x-pipe, K&N FIPK, FMS 1.6 roller rockers, 9mm wires,24lbs injectors,
190lph fuel pump, MSD cap and rotor, 18" wheels w/street tires, JMS custom chip, Trickflow phenolic spacer. ETs soon to come...

Rebel79 · 09-24-2001, 01:17 PM

Ok two things... we are in the same city! I wonder if I have ever seen your car or raced you!

I am experiencing the same problem with my JMS chip! If I let off the throttle and go back into it, the motor will go lean. It started happening a month or two after the install. It was kinda random and then started to happen almost all the time. If I reset the EEC it would start acting funny withni a week. Soon it would only take a day or two to act up.

Send me an e-mail and we should hook up! Shalihan@aol.com

------------------
1994 Mustang Cobra
308ci, Vortech S-trim 11#, ported GT-40 heads, E-303 cam, FMS 1 5/8 headers, BBK Offroad H-pipe, 2-chamber flows, and several other goodies.
Rebel Racing. Home of Bay Area Mustangs

moponys · 09-24-2001, 02:22 PM

Well that sucks about the chip...I was maybe gonna send it back to be retuned to be a little richer at part throttle.

That would be cool to hook up...I don't have any other friends with mustangs or even friends that are into mustangs. I think I've seen your car once on Treat Blvd but I wasn't in mine.

Maybe you've seen my. Did you look under user rides?

I want to go to the track soon (Sac or Sears Point). Did you do all the work on your car yourself?

------------------
TFS twisted wedge heads, TFS street intake, Lunati cam .500/.510 218/226, BBK FPR, BBK shorties, BBK 70mm tb, Pro-m 75mm, ASP pulleys, FMS 3:73, Transgo shiftkit,Flowmasters, Bassani x-pipe, K&N FIPK, FMS 1.6 roller rockers, 9mm wires,24lbs injectors,
190lph fuel pump, MSD cap and rotor, 18" wheels w/street tires, JMS custom chip, Trickflow phenolic spacer. ETs soon to come...

09-24-2001, 03:50 PM

Hey guys...I've got the JMS chip too. I've had it for about 6 months or so. I had a slight problem (with stalling out at idle rpm) in the beginning, but after I rest the computer, it's been fine. I've never had a pinging problem.....that's weird. Have you tried to call Chris Johnson about this?

------------------
'90 LX 5.0;12K original miles (no sh*&);3.55 gears; March pulleys;Edelbrock Performer Heads;BBK 1 5/8" equal length shorties;MSD 6AL ignition w/ blaster 2 coil;FMS E303 cam;Pro-M 75mm MAF;BBK 70mm TB; Eibach drag-launch spring kit;Southside welded subs;9" K&N cone filter charger;Hurst shifter;Cervini's 3" turbo hood;A/C delete; gutted cats;2 chamber Flomasters;Corbeau racing seats;FMS 30# injectors;JMS chip; Holley 190lb fp;TFS track heat Intake (12.299 @ 113 - 1.78 60')

moponys · 09-24-2001, 04:00 PM

I tried to call him earlier this morning but both lines were busy...This weekend, I'm gonna try to reset the cpu again by doing it the way you suggested a few weeks back.

I thought it was really strange too, that it would work great for a couple weeks and then not so great.

------------------
TFS twisted wedge heads, TFS street intake, Lunati cam .500/.510 218/226, BBK FPR, BBK shorties, BBK 70mm tb, Pro-m 75mm, ASP pulleys, FMS 3:73, Transgo shiftkit,Flowmasters, Bassani x-pipe, K&N FIPK, FMS 1.6 roller rockers, 9mm wires,24lbs injectors,
190lph fuel pump, MSD cap and rotor, 18" wheels w/street tires, JMS custom chip, Trickflow phenolic spacer. ETs soon to come...

Rebel79 · 09-24-2001, 04:30 PM

I live directly off of Treat, so that probably why you saw me there. Not sure if I was doing anything crazy at the time.

I don't recognize your car, but that doesn't mean I have not seen it.

I have done some of the work on my car, but definately not the motor buildup. Headers, H-pipe, intake, TB, Mass air, injectors, all that stuff is pretty easy. But there are some things that I just won't touch.

How about you?

I'll probably be working on either my car or my buddy's car tonight. You should stop by. Send me an e-mail and I'll give you directions if you are interested. I know a lot of people who are into Stangs, so you definately should join us!

Rebel79 · 09-24-2001, 04:33 PM

When I talked to Chris about it, at first he told me my Mass Air was bad, then he told me that my computer was fried. There is one thing that I can replace and probably should, and thats my o2 sensors. Thats the only think I can think of that would cause this problem.

09-24-2001, 11:44 AM	#1
moponys Registered Member Join Date: May 2001 Location: Antioch, CA 94521 Posts: 181	JMS Chip and 94/95 computer I have a 94 5.0 with a JMS custom chip in it. For the first three weeks after it was installed, the car ran great (better than ever) But just after that, it started to ping again at part throttle. I could figure it out and started thinking I was experiencing another problem. As an experiment, I reset the car's computer by disconnecting the battery for 30 minutes. After that, the part throttle pinging was gone again and the car, again runs great with no pinging what so ever. Is it possible for the computer to learn around the chip after a short period of time??? Please, any help would be greatly appreciated. ------------------ TFS twisted wedge heads, TFS street intake, Lunati cam .500/.510 218/226, BBK FPR, BBK shorties, BBK 70mm tb, Pro-m 75mm, ASP pulleys, FMS 3:73, Transgo shiftkit,Flowmasters, Bassani x-pipe, K&N FIPK, FMS 1.6 roller rockers, 9mm wires,24lbs injectors, 190lph fuel pump, MSD cap and rotor, 18" wheels w/street tires, JMS custom chip, Trickflow phenolic spacer. ETs soon to come...

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09-24-2001, 01:17 PM	#2
Rebel79 News Editor Join Date: Apr 1999 Location: Concord, CA Posts: 2,101	Ok two things... we are in the same city! I wonder if I have ever seen your car or raced you! I am experiencing the same problem with my JMS chip! If I let off the throttle and go back into it, the motor will go lean. It started happening a month or two after the install. It was kinda random and then started to happen almost all the time. If I reset the EEC it would start acting funny withni a week. Soon it would only take a day or two to act up. Send me an e-mail and we should hook up! Shalihan@aol.com ------------------ 1994 Mustang Cobra 308ci, Vortech S-trim 11#, ported GT-40 heads, E-303 cam, FMS 1 5/8 headers, BBK Offroad H-pipe, 2-chamber flows, and several other goodies. Rebel Racing. Home of Bay Area Mustangs

09-24-2001, 02:22 PM	#3
moponys Registered Member Join Date: May 2001 Location: Antioch, CA 94521 Posts: 181	Well that sucks about the chip...I was maybe gonna send it back to be retuned to be a little richer at part throttle. That would be cool to hook up...I don't have any other friends with mustangs or even friends that are into mustangs. I think I've seen your car once on Treat Blvd but I wasn't in mine. Maybe you've seen my. Did you look under user rides? I want to go to the track soon (Sac or Sears Point). Did you do all the work on your car yourself? ------------------ TFS twisted wedge heads, TFS street intake, Lunati cam .500/.510 218/226, BBK FPR, BBK shorties, BBK 70mm tb, Pro-m 75mm, ASP pulleys, FMS 3:73, Transgo shiftkit,Flowmasters, Bassani x-pipe, K&N FIPK, FMS 1.6 roller rockers, 9mm wires,24lbs injectors, 190lph fuel pump, MSD cap and rotor, 18" wheels w/street tires, JMS custom chip, Trickflow phenolic spacer. ETs soon to come...

09-24-2001, 03:50 PM	#4
bada$$lx Guest Posts: n/a	Hey guys...I've got the JMS chip too. I've had it for about 6 months or so. I had a slight problem (with stalling out at idle rpm) in the beginning, but after I rest the computer, it's been fine. I've never had a pinging problem.....that's weird. Have you tried to call Chris Johnson about this? ------------------ '90 LX 5.0;12K original miles (no sh*&);3.55 gears; March pulleys;Edelbrock Performer Heads;BBK 1 5/8" equal length shorties;MSD 6AL ignition w/ blaster 2 coil;FMS E303 cam;Pro-M 75mm MAF;BBK 70mm TB; Eibach drag-launch spring kit;Southside welded subs;9" K&N cone filter charger;Hurst shifter;Cervini's 3" turbo hood;A/C delete; gutted cats;2 chamber Flomasters;Corbeau racing seats;FMS 30# injectors;JMS chip; Holley 190lb fp;TFS track heat Intake (12.299 @ 113 - 1.78 60')

09-24-2001, 04:00 PM	#5
moponys Registered Member Join Date: May 2001 Location: Antioch, CA 94521 Posts: 181	I tried to call him earlier this morning but both lines were busy...This weekend, I'm gonna try to reset the cpu again by doing it the way you suggested a few weeks back. I thought it was really strange too, that it would work great for a couple weeks and then not so great. ------------------ TFS twisted wedge heads, TFS street intake, Lunati cam .500/.510 218/226, BBK FPR, BBK shorties, BBK 70mm tb, Pro-m 75mm, ASP pulleys, FMS 3:73, Transgo shiftkit,Flowmasters, Bassani x-pipe, K&N FIPK, FMS 1.6 roller rockers, 9mm wires,24lbs injectors, 190lph fuel pump, MSD cap and rotor, 18" wheels w/street tires, JMS custom chip, Trickflow phenolic spacer. ETs soon to come...

09-24-2001, 04:30 PM	#6
Rebel79 News Editor Join Date: Apr 1999 Location: Concord, CA Posts: 2,101	I live directly off of Treat, so that probably why you saw me there. Not sure if I was doing anything crazy at the time. I don't recognize your car, but that doesn't mean I have not seen it. I have done some of the work on my car, but definately not the motor buildup. Headers, H-pipe, intake, TB, Mass air, injectors, all that stuff is pretty easy. But there are some things that I just won't touch. How about you? I'll probably be working on either my car or my buddy's car tonight. You should stop by. Send me an e-mail and I'll give you directions if you are interested. I know a lot of people who are into Stangs, so you definately should join us!

09-24-2001, 04:33 PM	#7
Rebel79 News Editor Join Date: Apr 1999 Location: Concord, CA Posts: 2,101	When I talked to Chris about it, at first he told me my Mass Air was bad, then he told me that my computer was fried. There is one thing that I can replace and probably should, and thats my o2 sensors. Thats the only think I can think of that would cause this problem.