Jump to content
Aasan

No spark issue

Recommended Posts

Hi, 

I have a 93 corrado vr6. Currently the car is a non starter, the car cranks and is getting fuel just no spark. I am receiving a signal at the distributor (main lead) but it doesn't go anywhere past that. The the 3 wire plug attached to the dizzy is not giving me any reading. Looking at google I'm lead to believe that this goes direct to the ecu and I require a new ecu. Does anyone have any idea of what I can do apart from getting a new ecu? 

Share this post


Link to post
Share on other sites

Hello there,

as your VR6 has a distributor it won't have a crank sensor, so the ECU needs a signal to tell it that the engine is rotating, plus confirmation of ignition spark which it gets partly from the Hall sensor I think, which is inside distributor it's what the 3 pin plug is connected to on the side of dizzy, plus it's semi connected to the ignition coil. If the Hall sensor has burnt out then the engine possibly may not start up, as no signal to ECU. If the ignition coil has gone then engine definitely won't start up.

According to the Corrado Bentley manual, it says with ignition switched off remove the 3 pin connector plug from distributor, using a multimeter set at 20volts connect the leads to the outer terminals i.e (pin 1 and pin 3) switch ignition on you should see a minimum reading of 4.5volts or higher, if no voltage then could be wiring fault or a fuse blown or a problem with ECU ?

Hall sensor terminals: (has 3 pins)         Pin 1 =  Earth (-)  brown/black wire goes to terminal/pin 33 of the main 42 terminal/pin round engine harness plug.     

 Pin 2 =  Signal/pulse wire to ECU goes to terminal/pin 21 of the main 42 terminal/pin round engine harness plug, then from main round harness plug goes to terminal 44 of ECU  white/red wire 

 Pin 3 = Power (+) black/yellow wire

***********************************

The other thing to check is your ignition coil, if that has died then your Corrado 100% won't start up. Looks like the coil has a 3 pin connector plug, and is partly connected to ECU.

Pin 1 = Earth (-) brown wire this goes to terminal 6 of the 42 terminal round main engine harness plug, 

Pin 2 = signal/pulse wire black/red wire goes to terminal 8 of ECU

Pin 3 = power (+) black wire only powered when ignition is on or cranking engine over. Also is partly connected to terminal 38 of ECU

You should have battery voltage between pins 1 & 3 of the 3 pin connector plug for coil with ignition switched on.  (Multimeter set at 20 volts)                                                        Also on the coil there should be two contacts marked as (1) and (15)              (1) and (15) = Primary.                            (15) and king lead round socket (4) = Secondary.       

Measuring between (1) and (15) you should have primary residence of 0.5 to 0.7 ohms.

Measuring between (15) and king lead socket (4) you should have secondary resistance of 3000 to 4000 ohms.

The Bentley manual says if above readings are not within range or not obtained, to disconnect the battery earth lead, and remove coil and repeat test.

Regarding the coil you should have continuity between the terminals something like 7 to 8 ohms, or your multimeter should bleep to confirm you have continuity.                                   Also I think you can possibly check the signal/pulse operation is working, by measuring between pin 1 (-) and pin 2 (pulse) you should see pulses on your multimeter in volts, or I think you can use an LED pulse tester to check operation.

 

hope this helps

si

Edited by vw rule

Share this post


Link to post
Share on other sites

Good advice there on fault finding - but the dizzy VR does have a crank sensor - I know because I've replaced mine twice! The crank sensor is what tells the ECU that the engine is turning, and switches the fuel pump relay on, and maybe ignition too. But if you get fuel, that part is working. 

Have you checked/replaced the cap and rotor arm? The Hall sender is part of the dizzy and can't be bought separately as a repair kit unlike on some other cars, so you'd need to replace the whole thing unfortunately.

Share this post


Link to post
Share on other sites
2 hours ago, fendervg said:

Good advice there on fault finding - but the dizzy VR does have a crank sensor - I know because I've replaced mine twice! The crank sensor is what tells the ECU that the engine is turning, and switches the fuel pump relay on, and maybe ignition too. But if you get fuel, that part is working. 

Have you checked/replaced the cap and rotor arm? The Hall sender is part of the dizzy and can't be bought separately as a repair kit unlike on some other cars, so you'd need to replace the whole thing unfortunately.

Oh ok mate I presumed the later type VR6 with the full coil pack only has the crank sensor, I didn't think the early type with distributor had one.

Si 👍

Share this post


Link to post
Share on other sites

I think the coil pack had separate can position sensor instead of the hall sender on the dizzy version. Both had the CPS on the bottom front of the block.

Edited by fendervg

Share this post


Link to post
Share on other sites

Hi guys,

Thank you for your replies, I will test the multi plug as u suggested.

As for the ignition coil its brand new, I think this is the place where another 3 plug is connected but only one HT lead comes out of?

I have replaced the rotor arm and cap but not the whole dizzy.

If I pull the distributor will this give me any indication if it is okay or not? Or just change it?

 

Share this post


Link to post
Share on other sites

As Fendervg has mentioned regarding the crank sensor, if this sensor fails it can result in no spark. The crank sensor I think as Fendervg has said is attached to engine block, it's on the front side behind or under the oil filter area, think it pulsates off the toothed ring which is moulded/made to crankshaft, close to flywheel end of crank.

Regarding the distributor the safest way to remove it is to set your engine to TDC, once engine is timed up the rotor arm should be pointing to number 1 HT lead on dizzy cap, plus ideally rotor arm to be inline with the small notch cut out mark on the top side edge of distributor. Also you can use tipex or small chisel to make an in-line mark where the dizzy sits against cylinder head, just so you know then what position your dizzy was in (mark the dizzy and cylinder head where they both meet)

Yes your coil should have the one HT lead coming from it (The King Lead) which goes to centre terminal socket of dizzy cap.

So just to clarify you don't have any spark at all from your coil ?                        

 

Si 

Share this post


Link to post
Share on other sites

From memory, the VR6 distributor will only fit in one positions, so it's easy to remove and replace - I've certainly had mine off a few times and never needed to do marking or positioning. It might be different on the 1.8/2.0 cars.

Share this post


Link to post
Share on other sites
14 hours ago, vw rule said:

As Fendervg has mentioned regarding the crank sensor, if this sensor fails it can result in no spark. The crank sensor I think as Fendervg has said is attached to engine block, it's on the front side behind or under the oil filter area, think it pulsates off the toothed ring which is moulded/made to crankshaft, close to flywheel end of crank.

Regarding the distributor the safest way to remove it is to set your engine to TDC, once engine is timed up the rotor arm should be pointing to number 1 HT lead on dizzy cap, plus ideally rotor arm to be inline with the small notch cut out mark on the top side edge of distributor. Also you can use tipex or small chisel to make an in-line mark where the dizzy sits against cylinder head, just so you know then what position your dizzy was in (mark the dizzy and cylinder head where they both meet)

Yes your coil should have the one HT lead coming from it (The King Lead) which goes to centre terminal socket of dizzy cap.

So just to clarify you don't have any spark at all from your coil ?                        

 

Si 

Thank you for all the information, I'm only 21 so I've never really dealt with distributors and stuff. It is much appreciated. This is all on the list of things to check on the weekend.

The main coil has power, so the king lead is good, but doesn't go past this. The 3 pin plug attached to the coil has power, but the one on the dizzy is all negative.

I have replaced the main coil, bcm, HT leads, tried a different fuse box also. 

I am thinking of pulling the ecu apart, rigging a test bench and checking the resistors and such using a multimeter. But want to rule out all other issues first.

Share this post


Link to post
Share on other sites

Did you buy the car as a non runner?

 

A faulty crank pos sensor will give no spark or fuel.

Do you have fuel at the rail?

Are the spark plugs wet with fuel after cranking and removing them quickly afterwards

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...