3 Huge backfires, cut out then backfire after cut out? HELP

Smiithy · Post by **Smiithy** » Fri Jul 22, 2016 12:44 pm

Hi Guys,

First real post on here. Been trawling though but cant find anyone with my exact symptoms.

The car
2.0 16v Corrado, running R1 carbs with TPS and megajolt with EDIS4

History
The car was built up and ran a few times up and down the road before going to Bogg Brothers for rolling road setup.

It left the rolling road running good, and then I proceeded to take it for its MOT.

It failed its first MOT but the point here is it drove fine on the rollers for 3 hours, and drove to the MOT station and back (10miles round trip)

This week I took her back to the MOT station for the re-test, ran fine down there, although rich due to the insane hot weather we have at the moment, sat ticking over on the ramp fine with fan cutting in and out.

After re-test was complete I proceeded to drive back, with coolant temps being high I drove really steady for a few miles until all temps dropped to a reasonable level.

Now for the good bit!
Gave her some stick down a duel carriageway and then slowed for a roundabout and as I chucked it in I got 3 HUGE backfires and a lot of black smoke out the back and then it cleared and continued for 600yards before I reached a junction where it cut out as soon as I stopped. After cutting out another bang from the exhaust (engine not even turning over at this point). Engine restarted after cranking for 20secconds and then drove me around a mile before dying again on my drive. Again it restarted pretty quick and pulled down the driveway.

So I was pretty annoyed so left it for 2 days which brings me to last night...

I decided to see if it was weather related as it was a much cooler evening... took it out, started fine (first turn) idled good, although still on the rich side. Drove really nice, pulled upto 4000rpm lovely all sounded good until 1.2miles down the road BANG BANG BANG and come to a hault. This time the car wouldn't restart and I was towed home. On the driveway it started for 30/60 seconds and cut out and wouldn't restart again.

One thing I have noticed is that when this occurs the rev counter goes haywire.

Dose this point at a bad positioned / bad bracket or faulty crank pickup?
Or dose this sound more like a faulty EDIS4 unit?

I am going to fetch some plugs / leads / coilpack and vr sensor tomorrow just to swap for piece of mind but I feel this is more EDIS or VR sensor related?

Any help would be great, sorry for the huge post.

parky1972 · Post by **parky1972** » Fri Jul 22, 2016 8:17 pm

Disconnect the megajolt and run it on EDIS alone.
See if the problem is megajolt or the ignition map related.

But, from your symptoms.. It could be a sticking valve, bent unseated valve....

Jason.

Smiithy · Post by **Smiithy** » Sat Jul 23, 2016 10:56 am

Wouldn't a bent / sticky valve be a problem all the time not just when it all warms up?

Smiithy · Post by **Smiithy** » Sat Jul 23, 2016 11:17 am

Also why would a bent or sticky valve cause the rev counter to go haywire? Got to be edis or megajolt for rev counter to go loopy surely?

parky1972 · Post by **parky1972** » Sat Jul 23, 2016 11:12 pm

Just putting ideas in there.
I suggested the engine fault as you said iut only happened after you "gave it some"

I did recommend disconnecting the Megajolt.

You could also try replacing the EDIS with another.

Otherwise, it's likely to be a wiring, cps mount or engine issue.

How is the rev counter connected? Via EDIS, megajolt or to the coil pack?

Have you tried connecting a laptop and going for a drive with the data logger running?

Jason.

Smiithy · Post by **Smiithy** » Sun Jul 24, 2016 7:50 am

Update.. Last night she wouldn't start atall so changed the crank sensor and beefed the bracket up (added 2 gussets) and its started first time.
Test run in a few hours, hopefully that was all that was wrong.