Compression Test Gone Wrong....

[gerry 5]

Well as title i did a compression test on my gti but i messed up

 

Did the test on a warm ish engine just by screwing in the tester in the plug holes 1 by 1.

 

I didnt take the coil lead off and i actually let it run for a sec or 2 on each cylinder, which was fine on the 1st four runs and readings all (120 ish) then i did it all again to make sure the readings were consistant and on the final test the car wouldnt start at all?

 

Now i know i have messed up doing it the way i have done it

 

But what i dont get now is why the car wont start at all??

 

It turns over just wont fire there is fuel getting to it but i dont think the spark is there??

 

Any ideas anyone before i just start buying bits i dont need??

 

Bits that are new on car are plugs, leads, cap and arm are about 6 months old also.

 

I was thinking it maybe the ignition amplifier??

[rescue dude 0]

It could just be a coincidence that something has decided to fail. I'd check Ignition amp and coil.

 

What was the reason for the compression test?

[gerry 5]

Because i wanted to see what the compression was!!

 

I wish i had left it alone now lol

 

I am thinking it is down on power also....

Edited August 31, 2010 by gerry

[rescue dude 0]

Because i wanted to see what the compression was!!

 

 

Really?

 

Well duh!!

[GLPoomobile 958]

The compression results will be wrong anyway. You said you let it run for a few seconds, so I assume from that you hadn't pulled out the fuel pump fuse or disconnected the injectors etc. If that's the case, and it was injecting fuel while you were cranking, the compression will show higher than it really is since you will have fuel in the cylinders Maybe you've flooded it, and that's why it won't run.

[gerry 5]

Yeah didnt do any of that

 

I did however take out the new plugs afterwards and replaced them with the old ones thinking i may of knackered the new plugs up or at least one of them....

 

But that still hasnt let it start....

[Henry Yorke 269 3 Cars]

It does sound like a bit of flooding may have occured or you have dislodged an HT lead. Are the sparkplugs sparking when out of the car and onto the block?

[gerry 5]

According to the wife, when i turned the car over with a spark plug attached to a lead she couldnt see a spark...

 

Checked all the leads at both ends several times

[Daviewonder 533 3 Cars]

According to the wife, when i turned the car over with a spark plug attached to a lead she couldnt see a spark...

 

Checked all the leads at both ends several times

 

Not meaning to sound sexist but you might get more luck trying this the other way round, at least you can make sure the plug is earthing then

[gerry 5]

Yeah i will do at the weekend lol too dark now and i am working the next 2 days on 12hr shifts

[gerry 5]

Couldnt wait...!!

 

Went out with a touch attached a plug to a lead again got the wife to turn the car over in the pitch black and couldnt see a spark at all

 

What do you guys reckon change the coil and ignition amplifier module?

[ORB 227 1 Cars]

when did you last look at your rotor arm?

 

have you tried putting a spark plug directly into the coil king lead?

 

are the plugs wet with fuel? they wont spark if so.

[gerry 5]

Not tried a lead off the coil, plugs were a little wet but i dried them off and still no start

 

Rotar arm looks like new and is fine same with cap....

[gerry 5]

Just went out and attached a lead on the coilpack then plugged a plug in and no spark

[mickie 3]

do you get 12v on both sides of the coilpack ? with ignition on..

 

do you get an alternating current (AC) from your dizzy ? or do you have a crank sensor ? they'll have 3 wires, 1 earth the other 2 are for AC to your ignition amp..

 

if you get 12v to your coilpack and you get some sort of AC then it'll be your ignition amp

 

when i test for spark i just take the king lead off the dizzy and lay it next to an earth, turn over, look out for a spark, you should have lots of strong sparks, not just 1 or 2 crap one's

Edited September 2, 2010 by mickie

[gerry 5]

Ok cheers will try that