North American Turbocoupe Organization



?? on MSD Tach Adapter
Pete D Offline
Administrator
#1
I'm trying to solve some high speed engine miss problems.

I have an MSD coil. I have an MSD box, disconnected because it is dead. However, I still have the MSD Tach Adapter hooked up. Would that cause my stock tach to be inaccurate. It just hasn't seemed right for a lon time but I couldn't nail it down. I can disconnect the adapter but I'd like to know if I need to since I put it in a PITA place to get to.

Another question for you guys that have gone to big turbos on the stock injectors. Around what psi did you run out of fuel. What did it feel like? If you cheated on the fuel pressure, how much did it take and how much psi boost did it let you increase? I'm running an SC50, http://www.s-rracing.com/index.php?act=v...6c02cfecfe
with a .48, stage 3 hot side, stock IC. I'm currently pusing 44 psi and engine is breaking up bad around 5400, if the tach is accurate. see above. Just did a complete tuneup today and turned the boost down from 19 to 15 and still got the problem
Pete Dunham


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thecrusher315 Offline
Senior Member
#2
Pete, In my experience, when the engine runs out of fuel under acceleration, it feels like the engine just quits pulling and the car kind of noses over. When you shift gears the power usually comes back and then noses over again around the same RPM. With the low boost you have it set at, even with the larger turbo, it does not sound like a fuel problem. It does sound like an ignition problem though. It could be in the primary or secondary side. Check your voltage coming in to the coil to make sure it is right. It might be the coil bleeding power at higher RPM's or a resistance problem within the coil or it could be a problem in the distributor, TFI/PIP issue. If you have one, throw a stock coil on there just to see if that cures the problem. Also, The tach adapter may be your problem with your tach. I do know that the tach will not work, with an MSD, without it, so it would stand to reason that without the MSD hooked up, the tach might be inaccurate with it. Disclaimer...Just my thoughts on the matter. None of this should be taken as literal, only as suggestions. [Image: biggrin.gif] Hope this helps...Tommy

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Tommy Moore

Code 33 Silver Blue Clearcoat Metallic 1987 Turbo Coupe, Shadow Blue interior, 5 Speed with Spec stage 2/3 clutch/pressure plate, Hurst shifter, Gillis valve, 140 mph speedo, Auburn Posi unit with 3.73 gears,Flowmasters, KYB struts, shocks , and quads, 2nd and 5th owner of the car. I just had to buy it back.
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Pete D Offline
Administrator
#3
Tommy, I was thinking along the same lines. I will throw a stock coil on it and see what happens. I'll try to call MSD on the adapter because I need to make arrangements to get the box fixed anyhow. I may just disconnect it for now anyway

The way it runs it hits around 5400, breaks up, like ignition, takes off, breaks up. Just seems to keep up that cycle and there is no sense staying in it as it breaks up bad
Pete Dunham


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thecrusher315 Offline
Senior Member
#4
Quote:Originally posted by Pete D:

The way it runs it hits around 5400, breaks up, like ignition, takes off, breaks up. Just seems to keep up that cycle and there is no sense staying in it as it breaks up bad

Pete, definately sounds like an ignition problem. And it sounds like it is in the coil or distributor according to your discription of it. I think your on the right track. Keep us posted on what the problem turns out to be.....Tommy


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Tommy Moore

Code 33 Silver Blue Clearcoat Metallic 1987 Turbo Coupe, Shadow Blue interior, 5 Speed with Spec stage 2/3 clutch/pressure plate, Hurst shifter, Gillis valve, 140 mph speedo, Auburn Posi unit with 3.73 gears,Flowmasters, KYB struts, shocks , and quads, 2nd and 5th owner of the car. I just had to buy it back.
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Jeff K Offline
Administrator
#5
Pete, you have a narrow band "bar graph" A/F gauge, right? Does it stay full rich or nearly so, or does it drop? Did you monitor fuel pressure to be sure it is keeping up?

As for the tach adaptor, I dont know if it will affect tach accuracy or not if left in there with the MSD box disconnected.

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Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 23 psi, forced air intercooler, water injection, bypass valve, Ranger roller cam, subframes, etc., etc.. // 86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP nitrous, ignition, gears, suspension, etc., etc.... // 91 Escort: Bone stock winter car // 04 Taurus Duratec (wifes car) // 91 Topaz (daughters first car)
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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teal95 Offline
Senior Member
#6
I'm not sure how you have it all wired up but I've had a bad TFI show similiar problems. I was drag racing my '95 GT and it just would pull over 4500. It didn't die at the point, the power just dropped way off. Replaced the TFI and problems solved.

steve
'83 & '84 GT turbo EEC-Tuner
'85.5 & '86 SVO twEECer
2x '87 & '88 TC QuarterHorse
'93 LX 5.0 notch Moates chips
3x '95 & '96 GT
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Pete D Offline
Administrator
#7
I called MSD and got an RMA# for the 6AL box. $20 to $76 to repair IF repairable. I asked about the tach adapter and they said that runs through the box to amplify the signal, so if the box is disconnected the tach adapter should'nt come into play. They did, however, highly recommend disconnecting it????

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Dues Paying NATO Member. It's not a vice, it's an obsession

Campaign Chairman of the Glenn for President of the Dan S. fan Club campaign.
My biggest fear is when I'm dead, my wife will sell my car for what I told her I had in it!!



88 TC X 2, 86 SVO, 04 Escape. 92 F150 I6. Mods list at
http://www.turbotbird.com/showroom/pd_88tc.htm
Pete Dunham


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Pete D Offline
Administrator
#8
I got the stock coil on. Still breaks up around 5500 on the tach but it seems not to break up as bad. I ried staying in it and it just cycled back and forth between breaking up and smooth.

The narrow band AF does stay full rich at max boost (tried 15 and about 17-18psi) Fuel pressure does just what it is suppose to also.

I'm wondering if I'm bouncing off the rev limiter. Whats the likely hood the stock tach is off by several hundred RPM (700 to 800)?
Pete Dunham


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Jeff K Offline
Administrator
#9
I suppose it is possible the tach is off. Does the tach seem to match the speedo.... about 2900-3000 RPM at 80 mph?

DO you have a known good dist you can pop in to rule out TFI/PIP trouble?

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Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 23 psi, forced air intercooler, water injection, bypass valve, Ranger roller cam, subframes, etc., etc.. // 86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP nitrous, ignition, gears, suspension, etc., etc.... // 91 Escort: Bone stock winter car // 04 Taurus Duratec (wifes car) // 91 Topaz (daughters first car)
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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Pete D Offline
Administrator
#10
Jeff, If anything the tach seems to read low. I think I'd have to be doing about 90 to see 3K rpms but I also know the speedo is off by at least 5-6 in that range,. The speedo reads faster than actual speed.

I could swap in the dist out of one of the other cars but can't get to it until next week.
Pete Dunham


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