Starts and dies...

godxilla2 · 03-19-2006, 04:41 PM

i have an 86 carrera. I now have a full tank of gas. My car has been acting up in the last couple days. It died at a stop sign near my house yesterday, i had to keep it revved real high to get home. Today it started ok, the first time. I drove it around the block and it died. I again had to revv it real high to get it home. Now it starts up for a second, than dies.

Whats going on??? any help would be appreciated....

Thanks

kqw · 03-19-2006, 05:15 PM

Check your vac. hoses especially the breather hose behind the throttle body.

Also, spray a little WD40 or carb cleaner aroung the bottoms of your your intake pipes and see if your idle rises. If so you need to re-torque your intake manifold bolts. ALL 12 of them. 8mm hex head bolts torqued to 18ft/lbs. I bet that'll solve your issue.

godxilla2 · 03-19-2006, 06:24 PM

do you think it could be a clogged fuel filter? It has been sitting for about 1 hour, and i just started it up. it idled ok, but i am afraid if i take it out, it will do the same thing. i read on another post that if i have particles in the fuel lines they can sink to the bottom of the filter while the car is off. When i start the car they will eventually become shaken up and cause the car to die. Any idea if that could be at play?

kqw · 03-19-2006, 06:29 PM

Possible...It could also be a batch of bad gas.

ZOA NOM · ZOA NOM's Garage

DME relay under the driver's seat. Buy two, replace it and keep a spare i nthe car.

godxilla2 · 03-19-2006, 07:24 PM

if the DME relay is bad, would the car be able to start at all? it seems that if i let the car sit for 20min, it will start up and idle ok for a while. Even drive ok for a while, then it will die at a stop sign.

kqw · 03-19-2006, 07:32 PM

I bet it's the manifold bolts that need torquing down.......

ZOA NOM · ZOA NOM's Garage

Quote:

Originally posted by godxilla2
if the DME relay is bad, would the car be able to start at all? it seems that if i let the car sit for 20min, it will start up and idle ok for a while. Even drive ok for a while, then it will die at a stop sign.

They go bad intermittently, and cause the symptoms you describe. The solder joints at the base of the relay develop cracks that flex and break the connection. When it shuts the car down, usually, you simply turn it off and back on again, and it will run for a bit. This can last for awhile before the relay completely fails.

godxilla2 · 03-19-2006, 10:01 PM

Is the fact that if I keep the RPMs revved high i can prevent the engine from quiting consisent with a bad DME Relay?

WydRyd · 03-19-2006, 11:55 PM

- Idle Position Switch? (continuity at closed position and open circuit once throttle is open).

- Faulty ICV/ISV? (remove and clean out gunk with carb cleaner)

- BIG vacuum leak? (does it pop and backfire too?)

- Faulty AFM?

MBEngineering · 03-20-2006, 04:59 AM

HI you gotit Wydryd the idle switch first, and poss bad connection on one of the crank sensors??

regards mike

ZOA NOM · ZOA NOM's Garage

Quote:

Originally posted by godxilla2
Is the fact that if I keep the RPMs revved high i can prevent the engine from quiting consisent with a bad DME Relay?

Can you keep it running indefinitely by revving it? If not, then it is consistent with a bad DME relay.

You've described symptoms that I have experienced. My problem (as well as many, many others on this board) was the DME relay (search). It is an inexpensive part to replace, and is a good place to start. If you would rather try to eliminate the relay as a possibility by narrowing your interpretation of the symptoms, be my guest. Many have gone that route before you.

kqw · 03-20-2006, 06:44 AM

While the DME relay is certaintly a possibility and everyone should carry a spare. Swap that out as suggested by several folks here on the post.

There are several steps you can take prior to swapping out parts.

Check all of your vac. lines. There aren't that many so make sure they are all secure. Are you familiar with the location of all your vac. lines?

With the car off, slightly lift the throttle lever up and down and you should hear a slight "clicks". That's your Idle position micro switch. Do you hear any clicks???

When there is a intake manifold leak, the symptoms you describe are consistent. Car stalling when stopped, having to rev. the engine to keep it going.

There are 12, 8mm hex head bolts (2 per cyl.) and while you will have to maneuver around to get all 12, torque them to 18/ft/lbs.

What have you done so far to attack the issues besides asking about the DME?

ZOA NOM · ZOA NOM's Garage

Very good advice, KQW.

godxilla2 · 03-20-2006, 09:02 AM

i just put in a new DME relay. same problem. Starts and dies.

the intake manifold leak item is next on my list. never done this before. Are the bolts easily accessible?

Thanks

ZOA NOM · ZOA NOM's Garage

Well, it was an easy swap, and if your relay was old, it's better to have that out of the way. You can search for a leak with a can of carb cleaner or fuel injector cleaner by spraying it around the suspect areas while the car is idling. If the rpm increases, you've found a leak.

godxilla2 · 03-20-2006, 12:58 PM

I had a mechanic take a look at it today. After 3 hrs of testing, they say that my car's computer fails when it heats up and need to be repaired. They estimate a couple hundred $$$ for the computer repair, plus the time they took to find the problem.

Has anyone had any experience with a faulty computer?

Arrggg.

WydRyd · 03-20-2006, 02:05 PM

I've heard that the injector drivers can go bad in the DME, so maybe that's what your mechanic is referring to? Perhaps it is heat related

kqw · 03-20-2006, 04:40 PM

Where are you located?

ZOA NOM · ZOA NOM's Garage

Ohh... I don't like that advice from the mechanic. I would eliminate everything else before you start suspecting the DME. The DME is a very robust, reliable module, and rarely is the cause of problems. The Bentley manual even advises not to suspect it as a problem. If there is a heat problem, You might look at your Cylinder Head Temp sensor. Certainly, before you spend money on sending the DME out for repair, you should swap it with a known good one to confirm.