Weird vacuum question

[PJR-Elan]

Hi all,

Still problem-solving to get my project running sweetly. The problem remains that she sometimes stalls when up to temperature- e.g. at traffic lights. I’ve set base timing, cleaned sensors and corrected a detached vacuum pipe of the 2ndary throttle actuator around the back of the engine. I’ve reset the ECU too.

When checking the vac lines I noticed the egr vac lines were wrong. One went into the top of the EGR solenoid thingy. I have put both vac lines on the two bottom ports with the lowest one taking the vac from the manifold and the higher one going to the egr valve. Difficult to see if that is correct when looking at the diagram in the WSM. are they the right way round?

Anyway, now the pipes are on “probably” the correct ports, the top of the egr solenoid valve has a port sticking upwards. Looking at photos of people’s engine bays, it looks like there should be a black cylinder attached there. Like a small black cotton reel. I guess it’s like a one-way valve - if so, have I found a vac leak? Can I get just that prt or do I need a new solenoid?

Grateful for your advice,

Phil

[GeoffSmith]

I think it's only an air filter to atmosphere for the Vacuum Switching Valve (VSV).

[PJR-Elan]

Thanks Geoff,

Do you think it matters which way round the two pipes attach at the base (mine has both ports on the base)?

I did an Elan Scan last night with her idling and the only thing I noticed was that the IAC was moving and the TPS was at 0.22v at idle. Temperatures looked ok, the idle was 950 and there were no fault codes.

The weird thing is that the idle problem only starts when the engine is warm (at which point the exhaust pops a bit on overrun). Sometime the car stalls whereas other times it is fine. If I stop the car for a minute or two it will be fine until it gets right back up to temperature.

On the basis you are right that the valve is just missing a filter, would I be right in thinking that the most likely causes are:
- a vacuum leak I am yet to find
- a sticking IAC?

I have a new IAC to fit in the next couple of days. Maybe that will help....

Thanks,

Phil

[PJR-Elan]

Little update:

I have replaced the IAC with a Meyle one - only issue is that the electrical plug fouls the manifold above so I had to shave off a little corner of the plastic plug housing to make it fit. I used small hex head screws rather than the normal ones as I could then use a mini ratchet socked set on them - much easier!

I also changed the MAP sensor for a Lucas one.

I then did a ECU reset and ........she still stalled at junctions......

...but then I remembered that I hadn’t reset the IAC air screw so I put the car in service mode and did that. Now she runs well and doesn’t stall at junctions (well, not so far anyway).

As I was on a roll I fixed the fuel filler drain tube, drilled a tiny hole in the boot to let out a bit of water under the tool-kit (will find leak another day) and waxoiled the rear chassis which was a bit scabby.

A quick wash and polish and the world seems to be a much happier place!

[PJR-Elan]

Reading the Service Manual, I now realise that my inoperative speedo might be causing the problem - the ECU is not getting a signal from the Vehicle Speed Sensor in the speedo (or at least the signal it is getting tells it the car isn’t moving.

I have a new cable but haven’t fitted it yet as getting the old one off the gearbox is proving tricky. With the speedo end disconnected, when I undo the gearbox end a bit, the tension in the cable makes it tighten back up when I let go.

Should I cut the cable? Then, presumably, the gearbox end will unscrew normally and can still use the top half of the cable to pull through the new one......

Cheers,

Phil

[Simon_P]

Do you know why the speedo isn't working? A likely cause may be that the spedo gear isn't seated correctly.

Either way, the easiest option is to remove the gear from the gearbox housing. Then you can check operation of the cable and unscrew it if needed. You can also check the gearbox oil. The gear is the filler plug - see gearbox oil change for more.

[PJR-Elan]

Simon,

OK, good idea.

I take it I should just take out the retaining plate and the withdraw the drive gear still on the cable end?

The cable is the original Lotus type and looks quite tired in places. I have a shiny SJ replacement to hand....

Phil

[Fredjohn]

The drive head at the gearbox end is a bu***r to remove, unless you are lucky. It took me about 2hrs of gentle wiggling it along with attaching strong string to it and pulling!

And this was after moving the lock tab out of the way. Tip: do not remove the tab entirely, slacken it and rotate it out of the way. However, once the drive is removed, it is easier to remove it the next time!

Once removed you may wish to do a bit of project creep and change the gearbox oil too.

[PJR-Elan]

I do fear project creep! I will certainly check the level, but the gearbox was replaced recently by a previous owner, so hopefully the oil has done very little mileage. The change is very nice and slick.

Is it not possible to extract the drive using the cable to pull on? Looking at the SJ cable, the end seems to screw down onto the drive mechanism.

[Fredjohn]

Is it not possible to extract the drive using the cable to pull on? Looking at the SJ cable, the end seems to screw down onto the drive mechanism.

By "drive head" I really meant the cable head: outer casing and shaft together. If the gearbox has recently been removed, the cable may not be so hard to extract. It doesn't screw in as such (there's no thread), just a very stiff push fit with oil seal and tab to retain it.

[PJR-Elan]

Ah, I think I have misunderstood what I have to do. I thought the cable unscrewed and then a metal clip held the drive unit in the gearbox.

From what you say, the clip needs to be undone and spun out of the way and the cable separated from the drive unit. I was misled by the replacement cable which has a threaded attachment.

[Simon_P]

I take it I should just take out the retaining plate and the withdraw the drive gear still on the cable end?

Yes, then you can twiddle the gear and see if the cable moves if it does the problem lies elsewhere and is probably just that the drive has not been inserted into the gearbox correctly - there isn't much else to go wrong.

[PJR-Elan]

The drive head at the gearbox end is a bu***r to remove, unless you are lucky. It took me about 2hrs of gentle wiggling it along with attaching strong string to it and pulling!

And this was after moving the lock tab out of the way. Tip: do not remove the tab entirely, slacken it and rotate it out of the way. However, once the drive is removed, it is easier to remove it the next time!

Once removed you may wish to do a bit of project creep and change the gearbox oil too.

It’s Christmas Day and I was lucky!

First because I managed to sneak outside unnoticed for 20mins.

Second, because I removed the locking tab and pulled the speedo drive out easily first time. A battery drill on the cable end told me it was working, so I reseated it all and it went in fairly easily. I put it in gear, handbrake off and rocked the car as I pushed the drive gear home.

A quick test drive and the speedo is working perfectly w/o a flicker!

Yesterday, as a temporary measure, I had a lower rear wishbone welded. My chap cut out a good section and then inserted tick new metal inside the void and used a magnet to hold it in place whilst he welded it. The rest of both wishbones resisted his screwdriver and looked very solid. This patch seemed to be caused by water entering the void where the brake pipe attaches. Long term I would like some nice galvanised wishbones.

[dapinky]

It's nice to see a decent welded repair on the wishbone - mine were patched up with fibreglass when i bought the red car

I have done some welding repairs on other elans, and (like you) needed to cut back a fair way to get good metal to weld to - but once done, they are nice and solid again.

[Rambo]

Long term I would like some nice galvanised wishbones.

Just don't think about buying them from Jeemy at Specialist Vehicle Solutions

viewtopic.php?f=85&t=26948&p=349024&hilit=Jeemy+wishbones#p349024

viewtopic.php?f=21&t=25370&hilit=Jeemy+wishbones

You'd be as well taking your £1400 and chucking it on the fire