ForumStalker

Hello All,

i have searched the forums and cant seem to find a situation quite like the one I'm having. I have an 84 targa with around 130k miles on the clock. It's runs and drives great, but on long trips (1-2 hours at least) it starts to sputter like it's not getting fuel and dies. This happens while it's driving, not at a stoplight or anything (freeway twice and city steets another). I've changed the fuel pump relay and a shop even swapped out the ECU thinking that was the issue as they couldn't find anything else wrong. The car needs to sit for hours before it can drive again. Temps all look good so no over heating going on.

My question is, what should I start with? It's a crappy problem to test as I have to drive a long way to see if it happens again and risk having to get towed (again...). My dad and I own the car are are coming to a point where we almost don't want to dive it for fears of it dying on us. Any help would be greatly appreciated. Thank you!

if not able to fix, anyone wanna buy a 1984 targa with stalling issues? Hahaha

Doug

n8kruger

Not sure if you replaced the DME relay but do so now if not. Replacing the fuel filter and checking the fuel tank for rust/obstruction come to mind as well.

Might want to check the motor ground and battery connections as well.

ForumStalker

Thank you for the reply. Changed the DME relay, but haven't checked the other items you mentioned. I'll look into those.

rusnak

Maybe have the coil tested?

09mageec

I wouldn't go offering it for sale just yet. Definitely some lurkers that would steer you wrong as far as troubleshooting goes.

There are also some folks with seriously useful knowledge here as well, so keep an eye out for that. Also.... HANG ON TO IT!

ForumStalker

I'll check the ignition coil with a multimeter as well. Thanks for the suggestion

rusnak

Well, that's ok too, but the coil needs to have a load applied, which is why a weakening coil doesn't fail until it heats up.

rusnak

Another question: When it dies, do you notice any smoke out of the exhaust pipe? Is the cat glowing red hot? Does it sputter first, then die or is it all of a sudden like a switch is thrown?

ForumStalker

Thanks for the reply. What would be the best way to put the coil under a load and test it? Hooking it up to a 12v off the car for an extended period prior to testing or just running the car at idle for a while before removing?

It's sputters first for around 15-20 seconds like it's trying to die, then it stalls. Not like a quick shut off. Gives you a few seconds to try and pull over under reduced sputtering power. Then it doesn't start. Only happens well into a lengthy drive.

theiceman

okay a few troubleshooting tips . it is unlikely something is going to fail when you test it , because when the car is working, the part will test fine. I don't normally suggest part swapping but since this does it when the car is warmed up I would suggest some parts that you could consider preventative maintenance anyway .

1. coil ( make sure it isn't a silver Brazilian coil )
2. crank position and reference sensors, can crack , and become intermittent or just fail .
3. CHT sensor, ( this one is easy , if your car dies , jumper it out with a paper clip and see if it starts and runs , if so it is failing and falsely richening your mixture which will stall your car. Also this should be updated to a two wire sensor over the old single wire which was notoriously unreliable.

rusnak

You can probably find a shop to test the coil, or try calling Vato Zone or the like. They usually won't charge, or charge only a very small amount for the test.


#3 is a definite possibilty.

What I would do is order Bentley Publishing's 911 Carrera Service Manual.

Look for it on Amazon. There is a good troubleshooting guide. You need only that and a reliable digital multimeter to test many components. You can get a cheap fuel gauge at Harbor Freight. I'd probably get the Master Kit with all of the attachments.

You can also rule out the DME too. The DME test plan and the Bentley manual will go a long way to logically test your ignition and fuel systems.

rusnak

One more:

This is from Specialized ECU, who are great guys. Very helpful.

ForumStalker

Thanks for the replies guys. reporting back after checking out the car for a bit today after work:

Fuel tank looks good with no signs of rust and the fuel filter was just changed 18 months ago.

Ignition coil looks original (or just old) and I do not see it having been replaced in the past 5 years on my paperwork, so I think I'm just going to buy a new Bosch one and install it.

spark plugs, Distributor cap and rotor replaced in August 2014

CHT sensor looks to have been replaced sometime before my ownership (5 years) as it looks newish, BUT it has a nasty kink in the line. It looks like it had a loop in it and the installer just pulled it taught so I am wondering if that is affecting anything. I am going to purchase a new Bosch one and install. Figure I'll install new Reference and Speed camshaft sensors while I'm doing work in that area.

A local shop also said the fuel pump might be suspect, and since that looks original, figure I might as well swap that too.

Any other ideas on items I should be checking/replacing while I'm doing this? I'd like to place it all in one order if possible.

Thanks again!

theiceman

Sounds like none of those things I would consider a waste of money , and more like good preventative maintenance. Mine is the original coil from 40 years ago I think so they last quite a while.

Starbuckslova1

I really doubt the coil or cme Relay it would run rough I feel like.


I wouldent be supprised if it was the fuel pump.

Check the relays and see how warm or hot it gets when its dying it gets warmer to draw more current.

Also make sure your fuse box is not cracked and your getting a good connection. That was my issue hairline crack.

Crazy but check the alternator as well.