TR6 PI runs rich and bad/no idle

[DaveN]

Ok, one at a time to isolate the fault, but I'd still replace both items.

[Blue cedar]

Morton

 

Why don't you ask if one of the TR6 forum experts is able to help. Fly them out to yours on Easyjet. They resolve this kind of problem for a living. You can only ask ? I think one of our members had offered on an earlier posting.

[Peter Cobbold]

Morton, Before you fixed the fuel pressure it was firing OK. So its a trivial ignition fault. Maybe the disy cap is not clipped to the body correctly. Peter

[GT6M]

Morten, If rotor arm is gon, it,ll be shorting to earth

bung a volt meter onto it, then see what its reading,

batt + then to rotor, wid other lead

or,if thats not showing much, then an ohhm meter

rotor to earth point, this should read some thing

 

or a test bulb / screwdriver

 

One went on mine, and i had 12 V at rotor from batt connection wid meter

 

M

[MortenHoyseth]

Hi there

The rotor is brand new; switched between a few - all from dist.doctor. Multimeter readings are ok. Cap is also new, tried a few - same result.
I drilled out the center piece of a cap to see that the rotor arm actually is in position at e.g. TDC. It is, and it is not 180dgr off. I'm bothered that the gap between the rotor and the point in the cap is too long, both I'm told it is ok. I would guess it is 100 thou. It also does not seem equal at the point for #6 as for #1; like the shaft is a little off center. Just curious how the spark can jump that distance, when barely jumping the sparkplug. But again - this is beyond my knowledge. I also understand that the Pertronix Flamethrower coil is sensitive to 12v; it does not manage with low voltage at startup. And to make the Flamethrower work the plug-gap is set to be 40 thou; I've settled for 35 thou, though.
Next for me:
1 - Increase gap to 40 thou on all plugs. Test. If not work: next.
2 - Replace the Flamethrower with "original" coil. Test.
3 - Call for assistance - I've gone blind on the problem. If not success then:
3 - Call an ambulance - because I'm sure going to damage my foot kicking that engine for a few hours

[Guest ntc]

Check the base plate earth wire.

[MortenHoyseth]

Base plate wire is ok. Checked.

[MortenHoyseth]

Peter - it was firing occationally prior to the PRV change, however it was not doing idle and running rich. And also then it was running very uneven and hard (really hard) to fire up.

[88V8]

Did it used to work? Before you started doing whatever you did?

Does it still have a ballast? If so, do you have a ballast coil? Standard coil works crap with a ballast.

 

See

http://www.tr-register.co.uk/forums/index.php?/topic/29748-ballast-resistor/

 

Ivor

[oldtuckunder]

Ok we seem to have gone full circle back to where you were last year with this thread

 

http://www.tr-register.co.uk/forums/index.php?/topic/58585-tr6-pi-not-starting/&do=findComment&comment=486356

 

Its a triffle hard from your couple of threads to work out if you ever resolved the original problem and everything was running OK, and now you have hit a new problem, or if you have taken a break from working on it and we are picking up somewhere further down the chain of my engine isn't working properly.

 

Did you ever get it running sweetly last year?

 

Alan

[DaveN]

Is there two defects here? Morten implies it was never running particularly well. It won't easily fire up if it's flooded or overchoked.

So a couple of things to look at on the fuelling side.

Check the vac hose is in good condition and connections are good from the manifold to the MU

Check the vac hose is in good condition and the connections are good from the manifold to the brake servo. (In fact you could temporarily disconnect this hose and plug it!

Check the MU cavity drain tube is clear, especially the short bit of rubber hose in the left rear wheel arch as it can and does collapse with age.

Fully charge the battery. And give it plenty of throttle when cranking it over.

[oldtuckunder]

I think "running particularly well" is probably a great exaggeration

 

I suggest before suggesting anything else anyone reads the following two threads in order and completely, it will probably give you some idea of the full extent of the problem you are addressing!

 

http://www.tr-register.co.uk/forums/index.php?/topic/58585-tr6-pi-not-starting/&do=findComment&comment=486356

http://www.tr-register.co.uk/forums/index.php?/topic/58978-tr6-pi-starts-with-a-bang-then-dies/&do=findComment&comment=490850

Alan

PS and if you keep getting Deja Vue experiences they appear real

Edited May 2, 2017 by oldtuckunder

[MortenHoyseth]

Hi folks – right, I’ve pretty much done the whole circle, and not looking forward to another summer not being able to run the TR6. Some areas are corrected as a results of the previous threads:

1) The dizzy was faulty – it was stuck in max retard (or was it advance – doesn’t matter). Quite hard to spot (for me). After rebuild it is timed ok. Fires 12BTDC approx.
2) The PRV was jammed in 145psi position. Replaced.

 

Obviously many other minor things during this journey that have been improved, like the electrics, but no real source of the problem. Have been learning a lot, though, but now it’s going in circles for me. Coil is no-ballast coil.
I’ve checked the sparks at the plugs (no strobe), and there is spark. And it is fuel coming from injectors. So it puzzles me why it does not fire at all. Compression is pretty much equal on all six. Checked vacuum on MU ok, and tried plugging the break servo vacuum.

I've checked multiple times - but might be something to recheck for me - the position of the valves on #1 and #6 when #1 is at TDC firing. #11 and #12 should be in balance, right? Never remember if valve #1 (from front) is exhaust or inlet?

[DaveN]

No1 valve is at the front it's no.1 cylinder exhaust.

With no. 1 piston at the top of its stroke AND both valves closed (the firing stroke) the rotor arm should be pointing to the no. 1 cylinder AND the plug lead should align with the rotor arm.

You have all the correct requisites for internal combustion that is: compression, fuel, and ignition.

So is it all occurring in the correct order?

Is the MU timing correct?

So again with no.1 on the firing stroke remove the no.6 injector lead from the MU and then remove the NRV from the MU. Looking into the hole you should see the rotor inside and there should be approximately half a hole visible in the rotor.

Edited May 5, 2017 by DaveN

[MortenHoyseth]

Thanks. I'll double check the valve positions. MU timing is correct.

[Peter Cobbold]

It may not be wrong spark timing. No sign of firing at all - no backfiring - suggests to me the sparks are too weak to fire into compressed mixture. Try connecting the ig side of the coil direct to the battery live terminal. That eliminates the ballast reistor that might be in the loom, poor ig switch and other casues of weak spark.

Dont leave the coil connected to the battery longer than necessary.

The plugs could be badly fouled after so many tests - replace.

Peter

[oldtuckunder]

From the previous threads I believe

 

1) You are now running a rebuilt dissy with points?

2) You are using the Pertronix coil that came with the electronic ignition that you currently have removed (if so and 1 is true its almost certainly the wrong impedance coil)

3) You have the plugs gapped at .040 as recommended for the pertronix set up, if so way too big for points condenser to handle, anything over 0.028 and your probably foiked.

4) Don't know what plugs your using but by now they probably have been soaked a few times, and a few makes like NGK never seem to recover from a soaking. So put a new set of plugs in probably just leave gapped as they come.

 

Alan

[MortenHoyseth]

I got the car running! I does not run very nice, but it runs. Still some issues. After I checked compression levels (good), here are the things I changed:

1) Replaced the Pertronix Ignitor with points/condenser. Set 15 thou gap and ran a diagnostic (ground, voltage levels etc).

2) Replaced all plugs with a used set. Cleaned and set gap to 25 thou. Checked sparks on all. Spark ok. The sparks were looking good also with the 40 thou, but I though let’s get back to the “original” setup.

I’m still using the Pertronix Flamethrower coil.

Tried a startup, and it actually started! I wouldn’t say it ran nice, but it ran. And it managed idle. I was so surprised that I switched of the ignition after just a few cycles. The engine kept running. I turned off the battery supply switch (cuts off 12v). The engine kept running. It might have thought – I haven’t run for a long time; now I’m gonna run no matter what he does. It stopped 5 secs later.

I went for a drive around the block today, and it runs veeery rough. Hopefully I’m back to mere ignition timing now. Hopefully.
So I guess – the old PRV giving about 145psi gave to rich mixture, now that is fixed. During this either the soaked NKV plugs got damaged (but I could see them spark) like you suggest Alan or the Pertronix Ignitor had a problem.

What I find concerning are:

* During fault finding, I find 0,4v between the negative terminal on the coil and ground. This is when ignition is turned, and positive side of coil is connected. Contact point closed. Isn’t this supposed to be 0v flat?

* The exhaust is quite blackish; is the mix still rich? The idle is running untidy at about 600rpm, but I cannot get it to rise without using the throttle. Opening the idle vent on the manifold does not increase the rpm, but I can stop the engine by shutting the air supply. I’ll check the spindles/butterflies for balance.

* Before starting up, I sat the static timing to 12 dgr BTDC. But when idling the engine runs smoothest/fastest way more advanced. I couldn’t see exactly but guess about 25 dgr BTDC. Way too much for any power when running with higher rpm.

Any suggestion to best next step is highly appreciated.

[Peter Cobbold]

But when idling the engine runs smoothest/fastest way more advanced. I couldn’t see exactly but guess about 25 dgr BTDC.

That 25 BTDC setting is probably the correct one. And may actually be 12BTDC, because the timing marks can shift in relation to the crank as a result of the rubber annulus distorting.

Check the timing marks against true TDC measured with a 'piston stop' in #1 plug hole.

Way too much for any power when running with higher rpm.

Did you check the power at higher rpm ? If it does not 'knock' ( detonate) and the power is better than at "12 BTDC" stick with that "25 degrees". And see if it runs better with less smoke.

 

 

That 0.4volts. Check the woven engine earth cable is sound and making good, paint-free contact on the block and firewall.

 

Peter

Edited May 8, 2017 by Peter Cobbold

[Guest ntc]

New plugs for a starter.

[oldtuckunder]

Great some progress!

 

+1 new set of plugs

 

Also check the resistance of that coil or post the part number, odds are if you bought it with the Ignitor its wrong for points.

 

Alan

[MortenHoyseth]

The coil should be ok, but I'll replace it with the old one and get a new set of plugs. I think the 12 plugs (2 sets mentioned) have run about 8 km in total, but they obviously could be damaged.
Ground seems to be very good.

[oldtuckunder]

The coil should be ok,

 

I wouldn't swap a new unknown for an old unknown, What's the part number, you can then check on line at their web site what the impedance is, if its OK for points and if they recommend for 4,6 or 8 cyl applications.

[MortenHoyseth]

Made some progess J

1. The coils are both 3ohm (non-balast system), measured ok. When I say “old” coils, they are up to 2 years old. The “old” I now switched back to is the 3ohm coil bought from Moss Europe(part TT2981) and the 3 ohm Pertronix is – yes tailored to go with contact-less systems (part 143-265 at Moss). I bought that from Distributor Doctor with the dizzy rebuild. Without contact-less system at that point.
   
2. Bought a set of new plugs NGK set them to 25 thou, and switched back to the “old” TT2981 coil. Started pretty nicely, and ran pretty nice at idle.
   
3. The plugs I removed (attached a picture) had become very black. I cleaned them before previous run, so all the soot is from about 5 minutes of idling.
   
4. Since I now got it to start, I stopped the engine after a minute. Then took out one of the brand new sparks. I could see tendencies of blackish stuff there.
   
5. As a digression. The engine will not stop (!). Switch of the ignition. Cut of the power. It continues to run “forever”. I choose to stop it by strangling it (stopping air supply via the manifold). I can hear both fuel pump and see ignition (obviously) run after power cut. So I guess there is a misplaced feed from the alternator that is not cut with ignition.
   Great fun – I’m actually glad it’s just running at this point, and sort this out later.
   
6. Now since the car still runs rich by the look of the soot – I can eliminate a few areas. The vacuum on the MU is ok. The PRV is working correctly giving about 108 psi. The compression seems to be ok. As far as I can understand I’m left with these areas:
   
   - Timing is not correct -> adjust dizzy (TDC actually measured to be at 0 dgr, static set to approx. 13 dgr BTDC)
   - Break vacuum unit leaking -> give rich mix ? (Is this assumption correct)
   - Butterflies not in balance -> measure airflow w/flow meter (but note: ALL 6 plugs were equally covered by soot. Would that be the case if not spindles are correct?
   - MU set to rich -> I’m not too keen on adjusting a newly overhauled MU done by Prestige injection.
   

Sorry for the length here – lots to tell

Edited May 10, 2017 by MortenHoyseth

[Guest ntc]

Unless you get the car out and up to full temp you will keep fouling the plugs.