GeorgeM

Just started the GT this AM to head out on a driving tour, and after 15 secs, car starts running rough with little power. Felt like a limp mode.

I did notice when I turned the key from off to on, before turning over, the tach needle spiked to 2-3k, then settled to zero.

I seem to remember reading somewhere that this was a indication of something, but I can't remember.

Any tips? Thanks

Adk46

That's a terrible thing to happen to such a nice car.

I can't help you, except to offer a place to stash the car while you figure out what to do - 160 miles away in the general direction of your home. Or, as I think of it, 35 miles beyond the Hagerty limit. There's a qualified vintage Porsche mechanic in Albany, another 75 miles, google for Bavarian Rocket Scientists. I hope it doesn't come to that.

Imo000

Are you out of gas? That's how mine acts when is about to run completely out. It can only supply enough fuel to barely feed one bank.

Bertrand Daoust

Sorry I can't help much but have you ask Jim or Bob about this?

Good chance that they can point you into what to look at.

Regarding the tach needle, mine does this sometimes - not all the times - but only when I shut off the car.
Don't know why exactly but if I remember this might be related in a way to one of the computer. But not sure.
The car is running good though.

Have you done anything to the car last night?

Good luck.

Mrmerlin

George has the LH ever been rebuilt?
Has there been any battery charging done recently or the battery disconnected?
Has the car gotten wet recently?
How many miles and has an intake refresh ever been done?
Have the coil wires been inspected for corrosion and a free run from coil to cap?

jcorenman

George, give me a call-- 360 three-one-seven six four four two.

Jim

linderpat

George - weren't you experiencing a similar problem recently at another event? I recall reading about something with your car, and if so, maybe related.

jcorenman

Green ignition monitor relay LED comes on, which side does that cut off?

soontobered84

Driver side, IIRC

jcorenman

Thanks. We didn't find anything obviously amiss, and engine runs OK for ~ 15 seconds until the monitor relay activates with a green LED. So probably one of the thermocouples ('91 GT).

Rob Edwards

Got the stuff to make a 3 way jumper? (Pin 87 to A1 and A2)

GeorgeM

Thx for the tips and quick responses... And offer for a place to stash it, Curt. Bottom line, fortunately, it still runs and I trailered it this year since they dropped the rule about trailering for the Preservation Group... No point deduction.

Intake refresh in 2013/14'. LH rebuild in --2010. No water recently, ign wires replaced during refresh. Coils are original, though (of course, my spare is at home). Only charging was a tender.

Issue at previous parade was unrelated. Never figured that one out and it resolved itself.

Many thx to Jim for the assist this afternoon. Rode with friends on the tour and he just happened to be in the parking garage when we returned.... Then I saw his post to give him a call.

I'll try the jumper in the AM.... Or maybe just load it up since we depart Thurs AM anyway. Thx for the pics & diagram, Rob.

Got a call from Concours Chair that they wanted the car in the tent for the awards banquet. Apparently, they chose it for some sort of judges award. No doubt due to the 40th anniversary of the transaxle cars. I was surprised to say the least. What an honor. Good thing I was a able to limp it up the hill.

Will keep you posted.

Mrmerlin

swap the coil wires see if the issue transfers,
then swap the final stages,
then put deoxit 100 on the thermocouple connectors
you will need a lift to get to them

supercedar

This is a whole lotta love!! You are awesome.

jcorenman

Stan, I am pretty sure it is a "false positive", engine runs fine for about 15 seconds until the monitor relay cuts the fuel and lights the green LED.

That suggests that the ignition system is working fine and the problem lies with the sensing-- i.e. thermocouple connections as you suggest. Thermocouple signals are only millivolts, it doesn't take much to mess them up.