3.2 carrera wont start

R&TSWB · 12-31-2008, 11:14 PM

Happy New year to all!
Got myself an 86 carrera with 11t miles on it, changed the clutch discs, rebuilt brakes, had a great time driving it!
Very reliable, started everytime, until last week.
The engine refuses to fire up if i try to start it immediately after switching of the engine.
Again if i wait between 3 to 5 minutes between swtiching of the engine and starting it, it fires up everytime.
Anyone ever have this trouble before, any ideas? thanks and regards romy

DonMo · DonMo's Garage

Go through the standard checks, DME relay, check input pins on motronic to see if any of your sensors are acting up, ignition switches do go bad, Motronics are known to have cold solder joints that are fun to find and fix (causes intermittent start issues). You forgot to put where you are from, a kind Pelican may be willing to swap Motronic boxes to see if that is your issue. Sure would save a lot of chasing ghosts.

Does your fuel pump run when you try to start (smell gas, hear the rrrr of the motor up front by steering ).? No fuel pump is dead giveaway on DME (relay or Motronic box).

R&TSWB · 01-01-2009, 05:50 AM

Hi DonMo,

Everything works well on the first start up and the car runs perfect. The fuel pump was checked and is working even when the engine refuses to fire up when starting/cranking the ignition immediately after shutting of the ignition. Sometimes it does fire up but more often i need to wait a minute or two before it starts with one click!

My wrench suspects the idle adjustment valve is not always working and have ordered the part to replace.

Thanks Rommy

tonythetarga · 01-01-2009, 05:56 AM

Are you saying you get the engine to turn over but it won't fire...OR... you get nothing when you try to start. Big difference. What EXACTLY does it do?

rick-l · 01-01-2009, 10:15 AM

Quote:

Originally Posted by R&TSWB

My wrench suspects the idle adjustment valve is not always working and have ordered the part to replace.

What is that?

Is this a turbo (CIS)?

Thrlls · 01-01-2009, 01:10 PM

R&TSWB - It may be the wire (not sure what its called) that goes to the cylinder I believe it has something to do with hot starting after shut down like you explained. The previous owner of my car had that problem and I noticed that wire is new.

I just experienced almost the same problem.
My car starts up everytime...well it did until this morning.
I pulled into work, shut down the car, checked in with the guard, tried to start the car and it started then died out. Now I can't get it to start again.
I changed our the DME relay (had one in the glove box) but still nothing.
The engine turns over fine, the battery is strong, almost seems like it's not getting fuel.
Once I get it towed home I'll check the fuel pump, but how do I check the Motronics?

R&TSWB · 01-02-2009, 05:44 AM

Hi rick, i checked , its called the idle control valve, and have ordered this from our host pelican.

Tony, the engine cranks strongly everytime, but does not fire up, i also checked that the fuel pump is working and it does. I just replaced the fuel filter but it still refuses to fire after trying to start the engine immediately after shut off.

Its like no fuel is getting to the engine like thrlls describes it?

But after waiting for a minute or two, it does start with one click. Seems like the fuel line is emptying and taking some time to presssurize? rommy

175mph951 · 01-02-2009, 07:53 AM

i would check the fuel pressure and volume the ICV wouldnt cause a no start issue just an erratic idle

pozee · 01-02-2009, 08:21 AM

Sounds like it could possibly be the speed or reference sensor. You should test them.

rick-l · 01-02-2009, 08:24 AM

A good test to see if you have basic DME functions is when it is hot and won't start pull a plug wire, put an old plug in and hold it up against a good engine ground to see if there is a spark.

DCinVA · 01-02-2009, 10:49 AM

+1 on the speed and reference sensors. I believe the bentley specifies a resistance test for these components. In this case it sounds like you have a failure when the engine is warm, but it works ok when it is cold. I suggest you test both sensors cold, and then again when hot.

175mph951 · 01-02-2009, 12:09 PM

Quote:

Originally Posted by DCinVA

+1 on the speed and reference sensors. I believe the bentley specifies a resistance test for these components. In this case it sounds like you have a failure when the engine is warm, but it works ok when it is cold. I suggest you test both sensors cold, and then again when hot.

the sensors are a square wave signal there for they are either on or off.....if a sensor is going bad and working intermitantly its because its loosing the magnativity(if thats a word) in its permenent magnet...in a hot/cold situation its becasue the aluminum bracket that holds them is expanding from the heat and there is not enough magnatism to make up for the change in distance. this can not be tested by the resistance. if you believe this is the problem they would have to be replaced with known good ones to test problem. if they are original from 1986 i would change them regardless just to prevent future problems. you can replace them with bmw sensors from early 80's 5series cars.....they are 1/3rd the price of porsche sensors and work the same....only difference is the length in the cable which works fine.

jlex · jlex's Garage

When you turn the car off, can you check to see what the residual fuel pressure is on your gauge? I think it should hold at about 14lb for about 20 min. afterwards. If it doesn't, your check valve on the fuel pump may be letting the pressure go down to 0, making it hard to fire. It may be firing okay cold because the system is compensating for a cold engine. If it goes down in pressure after shutdown, either its a bad check valve or a leaky injector that's releasing pressure & flooding your engine.....

regards,

jlex.

R&TSWB · 01-02-2009, 10:44 PM

Hi everyone, i found a leak in the crimped parts of the fuel line that is right below the idle control valve whee there is a T and the crimped side goes to the right side injector fuel collector tube and the other side goes to the left bank.

When i moved the hose at the crimped area , i noticed a drop of gasoline and then saw that behind it was like a red map of gasoline on the engine metal cover under the friver side intake manilfolds.

I looked for this hose part in the pelican parts catalog but its not available. Would anyone know where it can be purchased?

I now think this could be the leak that is causing the engine not to start immediately after i put of the engine? regards, rommy

rick-l · 01-02-2009, 10:47 PM

Quote:

Originally Posted by R&TSWB

Hi everyone, i found a leak in the crimped parts of the fuel line that is right below the idle control valve whee there is a T and the crimped side goes to the right side injector fuel collector tube and the other side goes to the left bank.

Kiss 500 bucks good by.

rick-l · 01-02-2009, 10:55 PM

930-110-595-05-m260

mine started fine with a dripping hose. I was worried about fire.

175mph951 · 01-03-2009, 11:08 AM

it lists for $531 but the wholesale price is $288 you should be able to ge one for$350

i might have a used one for $150