Thread: D1 3.9 running rough

Check vac advance is working. Suck on hose and dizzy should move a little.
Check timing. Wind it up till it pings then back it off a bit. Dont be afraid to wind it up here. 12 degrees i think some are able to run at.
Adjust MAF and throttle position sensor as per usual settings.

When running pull the maf plug. If the maf is dead i think it will make no chance. If its working it will die off and near stall.
A few other things can cause issues like coolent temp sensor so make sure they are working also.

Stepper is only for idle and should not be the problem.

My real thoughts are SPARK here. There appears to be an erratic spark for some reason.
Get timing light and hold on each pot one at a time for a while and see if you can spot the miss with the timing light.
If its random cylinders then you know the problem is up stream. Coil etc.

Silly as is sounds but its not a bad idea to try running it in the dark, sometimes a big enough miss can be seen if its arking off the plug or something.

Your not having much luck mate.

Check this link out. Lucas 14CUX Fuel Injection System – Installation and Diagnostic Notes. - ACT Performance Products - your source for after market TVR upgrades, components and performance accessories. Has some info on setting maf etc.

Originally Posted by DAMINK

Check vac advance is working. Suck on hose and dizzy should move a little.
Check timing. Wind it up till it pings then back it off a bit. Dont be afraid to wind it up here. 12 degrees i think some are able to run at.
Adjust MAF and throttle position sensor as per usual settings.

When running pull the maf plug. If the maf is dead i think it will make no chance. If its working it will die off and near stall.
A few other things can cause issues like coolent temp sensor so make sure they are working also.

Stepper is only for idle and should not be the problem.

My real thoughts are SPARK here. There appears to be an erratic spark for some reason.
Get timing light and hold on each pot one at a time for a while and see if you can spot the miss with the timing light.
If its random cylinders then you know the problem is up stream. Coil etc.

Silly as is sounds but its not a bad idea to try running it in the dark, sometimes a big enough miss can be seen if its arking off the plug or something.

Your not having much luck mate.

Check this link out. Lucas 14CUX Fuel Injection System – Installation and Diagnostic Notes. - ACT Performance Products - your source for after market TVR upgrades, components and performance accessories. Has some info on setting maf etc.

Thanks for the help mate! I think you may be right with vac advance. When I pulled the dissy apart I put the weights back in wrong, pulled them out again and all was good for a while I'll defiantly suss that out.
I havnt timed it with a gun but the problem was already happening before I pulled the dissy. I'll advance it some more and see what happens.
I've been pretty lucky with it, it's done 370xxx I only paid 800 for a really honest d1 and I've probably put that into it in 15000ks including RWC. When I get home I'll test the MAF it's running really rich so hopfully it just needs tuning.
Thanks again
Cheers

Also what about the charcoal canister any thoughts about that? I read somwhere to reroute the hoses once it packs in or should I just leave it alone?

Hey all

So yesterday I sprung for some new tools new multimeter and new timing light. I left the old multi in the rain doh! And i havnt seen a timing light since my dad sold his old datsun 20 odd yrs ago . Both just SCA ones but I got the better digital timing light tho which took a while to nut out all the features. Pretty cool has the advance settings which came in handy.
So I reset the timing again I couldn't find the marks again even after quikly cleaning it only the notch.
That's were the advance settings came in really handy. Just used the gun to set it back to 0° and then used the advance setting, pretty high tech for me lol. I ended up going for 6° for now may change it. Turns out I was off quite a bit originally I have a feeling I may have turned the dissy clockwise at some stage.
The timing sorted most of the misfiring out I may advance a whisker more and have a better listen. It's not all the time only missing now and then. And it's not as rich now must actually be igniting the fuel now ...

Next I moved onto the MAF, the bung was missing so someone's been there before me.
I can't remember what it was set at but it was very responsive I could adjust it up and down with ease and set it exactly to 1.0v without an issue. The screw was really really easy to move though is that normal? It's that easy I'd be worried the engine vibration would change it.
I couldn't find it in the rave Manuel but I'd read 1.0 is magic number.

It's now running much better still a little rich and still fluctuates a tiny bit at idle not enough to stall out but it's obvious.

Is the MAF setting right? I know I really need a Co2 sensor to test it.
My thought are maybe tweak the base idle a tiny bit?
Advance to 8° maybe what do other people run on I'd rather set for economy but that's a myth with these engines.
I still gotta test the vac it keeps slipping my mind.
And I'm gonna change the temp sensor is there one I could get from repco or bursons?
If it's the stepper what are the symptoms?

Cheers
Jim

Dont be afraid to turn up the timing on these old beasts mate. 8 or 10 degrees, dang even 12!! should not be a problem at all. But always listen for the ping. If it pings turn it back a degree or 2. More reliable than a balancer mark.

Use your timing light on each cylinder and check the pulse rate of the spark. Just visually is enough to detect a miss at idle.

As far as the maf settings i cant remember but will update this thread when i find the info sorry. That said when i do the maf i also do the TPS while i am at it. A good idea to set that before you play with idle.

Yes test the vac for sure. Make sure there is no leaks anywhere. Those buggers can cause all sorts of issues.

Temp sensor im not sure mate. I assume any of those shops would sell one but you can test them with you new multimeter anyway to make sure it works

Stepper motor controls idle basically. Well i think non metered air flow but basically to control idle. You can unplug that thing while its idling easy to test if its working. If its working it will stall. If not i think it will just keep running normal.
A bit of a pricey item to change when its unlikely to be the issue.

You have a miss which you need to resolve before you can really worry to much about other stuff. Stepper certainly is not the reason for a miss though. Crappy idle or high idle definitely it will do that.



EDIT... Oh yea put a liquid paper mark on the timing mark on the balancer. That way you can see it easily with the light.

Did you get it running better?

Something else i did to mine i forgot to mention.
The new amplifier you put on. There are 2 wires from the dizzy. If they are around backwards your car will run but run rough. You can tune it to almost run ok but never properly.
Check they are around the correct way.

Connect your timing light and swap them over and adjust timing to suit. Will be quite a bit out when you change these 2 wires. You should notice a big improvement to idle etc almost instantly.

Originally Posted by DAMINK

Did you get it running better?

Nah not yet i haven't been able to have a crack yet baby's been a bit sick and work and all that life stuff that gets in the bloody way.
I'm pretty sure that the amp wires are correct i think i changed them around before I can't remember.
But I'll defiantly have a go at it if you reckon you can tune it to almost good.
It's running pretty good though, definate misfire every now and then depending on engine load. And flutters at idle a little.

One thing that's really odd is some mornings on startup it idles really high 2000rpm then others it dosnt. Sometimes when it's warm it does too.
Others it revs up then high then drops down to 800.

I'm gonna replace the dizzy cap and temp sensor coz they would be well passed due anyway and see what happens.

Will get to it one of these bloody days!

Idle quality can be improved by moving the vac advance pipe from the timed before throttle disc position to the inlet manifold so vac is always applied. Theres even a spare take off port conveniently located in the drivers side base of the manifold.