Back Tracking.....

[Rockettvr]

My Offer of help still stands Smash- I'm not the best mechanic but I am an electrician so can find my way round the electrical system with no worries. Maybe a fresh viewpoint might help.
Don't break it - it's too good for that. I'd be interested but would need to move my 350 on to new pastures before I could make a deal as I've no spare cash at the moment.
Anyhow if I can help just send a PM
Ron

[superwedge]

have a deal,he keep the plate, swap cars,

[smash]

OK so new Bosch coil in and checked the TDC mark with dial gauge.

When is TDC not TDC? When it's 4 degrees after the TDC mark!

This probably explains why the timing was set to 4 degrees when I first checked it and then thought "that's wrong" and went about setting it to what I thought was correct at 8 degrees!

Anyhow after pfaffing around today it still really did not want to start - missing massively to start with then settled down after a minute or so.

Set the timing to 4 degrees per marking which is actually 8 degrees and although it was idling it always felt like it would cut out. After sopping and then attempting to restart we were back to the really don't want to start without holding WOT.

Compression test in order methinks just to rule out anything mechanical and then the suspect has to be fueling....

[Rockettvr]

Hi smash
Has the new coil solved the issue of the weak spark? How come your looking back to the fuel system as I thought you'd been through it already (changing afm etc. ) ??? Can vaguely see your reasoning - good spark , timing ok ,then must be fuel. When you try to start it have you had a plug out to see if it's wet ? If your turning it over for long periods trying to get it to fire you should get a strong petrol smell from the exhaust where unburnt fuel is going through the system.
I'm around if you need a hand
Ron

[red tasman]

Personally I would do a compression check before doing anything else.

[V8 Fettler]

Write yourself a flowchart Smash, this will show where you've been and guide you to where you need to go to (no, not the Porch dealer). Otherwise there is a risk you'll go round in circles.

[Rockettvr]

V8 Fettler said:

Write yourself a flowchart Smash, this will show where you've been and guide you to where you need to go to (no, not the Porch dealer). Otherwise there is a risk you'll go round in circles.

Flowchart !!!! You're not a management consultant by any chance are you ??? Lol

[V8 Fettler]

Rockettvr said:

V8 Fettler said:

Write yourself a flowchart Smash, this will show where you've been and guide you to where you need to go to (no, not the Porch dealer). Otherwise there is a risk you'll go round in circles.

Flowchart !!!! You're not a management consultant by any chance are you ??? Lol

Far from it! Resolving faults with non-automotive control systems for far too many years, it's very easy to go round in circles and cover ground already covered. Might get lucky with scatter gun, or could try this one:

[mrzigazaga]

V8 Fettler said:

...Like it!

[Rockettvr]

[Jack Valiant]

Been watching this with interest .... Do the simple stuff first please....

First have you had the dizzy out? Did you put it in 180 degrees out for the firing stroke?

Put straw in number one.... Is it at the top of its stroke when the rotor arm is pointing at number one lead on the cap? Take off the rocker cover on the passenger side or it you have access / borrow a endoscope and put it down the oil filler neck, are both valves closed? If so then check the timing mark is roughly in the ball park for the timing mark? If all is well then move on to dynamic timing with a gun.

Lets see how you get on after this fella

Chris

[smash]

Hi Chris - I used a dial gauge in adapted spark plug casing to check TDC which actually equates to 4 degrees after TDC on the markings so it's out but not massivly so and certainly nothing to cause the severe starting issues etc. I triple checked firing order btw, lol! using offset I set timing to indicated 4 degrees before TDC on damper markers which equates to 8 degrees in the real world.

Hi Ron - don't worry! I'm gonna be chasing you up to run through the wedge pages wiring check at ECU plug end assuming compression check is OK!

@V8fettler - yep, I'm going methodically I think (for me!) - not going to do anything more until I've tested compression and can (hopefully) rule out mechanical foul play.

Current characteristics = bd to start (needs cranking with WOT), runs rough misfiring massively to start with then smooths out to fire (audibly) on all cylinders and reasonably steady idle. If switched off still bdly difficult to start even when warm.

Edited by smash on Sunday 10th August 14:14

[Rockettvr]

No worries Scott
A quick heads up though - I'm busy mid week -tue to thurs but should be ok for friday or next weekend

[V8 Fettler]

smash said:

Hi Chris - I used a dial gauge in adapted spark plug casing to check TDC which actually equates to 4 degrees after TDC on the markings so it's out but not massivly so and certainly nothing to cause the severe starting issues etc. I triple checked firing order btw, lol! using offset I set timing to indicated 4 degrees before TDC on damper markers which equates to 8 degrees in the real world.

Hi Ron - don't worry! I'm gonna be chasing you up to run through the wedge pages wiring check at ECU plug end assuming compression check is OK!

@V8fettler - yep, I'm going methodically I think (for me!) - not going to do anything more until I've tested compression and can (hopefully) rule out mechanical foul play.

Current characteristics = bd to start (needs cranking with WOT), runs rough misfiring massively to start with then smooths out to fire (audibly) on all cylinders and reasonably steady idle. If switched off still bdly difficult to start even when warm.

Edited by smash on Sunday 10th August 14:14

How long will it idle for when warm? Does it drive OK when warm?

[smash]

Not even attempting to drive it lol! Will idle indefinitely with the odd save from dying with throttle.

Right - todays activity = compression check

bh to start again - warmed up to 75 on gauge then pulled fuel pump relay and king lead, removed plugs and the results went like this:

First test set

2 - 175 1 - 200
4 - 180 3 - 190
6 - 190 5 - 190
8 - 180 7 - 200

Decided to run a second set to double check inconsistencies and got these results

Second test set

2 - 230 (!) 1 - 210
4 - 220 3 - 210
6 - 220 5 - 200
8 - 220 7 - 200

Anyone got any thoughts?

[V8 Fettler]

smash said:

Not even attempting to drive it lol! Will idle indefinitely with the odd save from dying with throttle.

Right - todays activity = compression check

bh to start again - warmed up to 75 on gauge then pulled fuel pump relay and king lead, removed plugs and the results went like this:

First test set

2 - 175 1 - 200
4 - 180 3 - 190
6 - 190 5 - 190
8 - 180 7 - 200

Decided to run a second set to double check inconsistencies and got these results

Second test set

2 - 230 (!) 1 - 210
4 - 220 3 - 210
6 - 220 5 - 200
8 - 220 7 - 200

Anyone got any thoughts?

Maximum 10% variation is the usual rule of thumb. Averages = average!

When it idles warm, are you sure it's running on all 8? RV8 can run on 7 reasonably happily. Laser thermometer onto the headers, or spit.

[Wedg1e]

Is the cold start injector disconnected/ unplugged/ missing? Most RV8s will start in summer without it but it would be worth having it working just to eliminate it.

Having the throttle wide open would tend to make it harder to start as the cranking fuelling is calibrated to be correct with bypass air only, so effectively you're making the mixture too weak. It's not like on a carb where the airflow sucks the fuel through.

[smash]

Yep, cold start injector is unplugged.

All plugs came out very sooty/black

In terms of one cylinder missing I'd say it starts probably only on about 4 then the others join in slowly

Edited by smash on Monday 11th August 07:21

[V8 Fettler]

smash said:

Yep, cold start injector is unplugged

Wedg1e means plug it back in to try and improve the cold starting. If no difference following Wedg1ies suggestion, unplug it to remove a variable. Need to concentrate on getting that warm idle right, then go from there.

[V8 Fettler]

smash said:

Yep, cold start injector is unplugged.

All plugs came out very sooty/black

Edited by smash on Monday 11th August 07:20

Check all cylinders firing at warm idle, check fuel pressure at warm idle.