Stumped on Starting an S1

[Hegg]

My Federal S1 was running fine for the most part, although a little rough on idle and running rich. A week ago or so it stopped starting!

I've been through the timing and everything appears to line up perfectly. A spark tester and timing light shows that all 4 plugs are firing. New points, condensor, cap, rotor, wires, and plugs (they were new when it was running). Carburetors rebuilt and compression in all 4 cylinders. Fuel pump is pumpin' some good volume through and the carburetors get a little wet inside if I crank it for awhile and it doesn't start.

I'm stumped! What could I be missing? It turns over just fine, and occasionally it'll fire one or two cylinders. Mostly it seems that if a cylinder fires, it's the same one -- as in while I crank, the same cylinder is firing each time around (if it fires at all).

The last time I drove it, on the road right before my house I opened it up a bit (not ALL the way to the floor ) and it was going just fine. Once I let up, it was running a little odd, like it was misfiring while I was driving. Once I pulled it in and parked it though, I couldn't ever get it to run normally again. I did get it started once, but it was misfiring badly. It seemed like it was running so rich that it couldn't function right. If I pulled off one of the intake manifold vacuum lines, the engine RPMs jumped up to probably 1800-2000 and seemed to run smoother, which seems to confirm that it was too rich.

But just nothing at all now. I've tried swapped out the Stromberg piston/needle assemblies with some others from my TR7 as well, and that didn't help.

Even if it is rich though, it's 20 degrees Farenheit here, so the rich mixture would theoretically be just as if I'd pulled the choke anyway to help it start on these cold days. I've spent 8 or 9 days troubleshooting everything I can think of as I said before (timing, spark, compression, fuel pump, etc.) and nothing seems to help.

I'm hoping more for a sanity check type of suggestions. It's got to be something simple I'm just missing (like, "you are turning the key clockwise, right?" ). Maybe my coil doesn't have enough juice? But then I probably wouldn't be getting spark, either... I'm so frustrated!

Thanks in advance, and happy holidays to all!

[WayneB]

In the past I have had problems with holed diaphrams and sticking pistons in Strombergs.

Only have to have a tiny pinhole for them to play up something rotton.

Also make sure the piston is totally free to rise and fall and you are using the correct light oil in the dashpots.

The floats can also leak and get fuel logged, take them out and shake them to hear if there is fuel inside. That would also give a rich condition.

Hope this works

Edited December 17, 2005 by WayneB

[GSimpson]

If you have tried the above suggestion then look back at the ignition.

Try new plugs or at least clean them thoroughly. You haven't got the leads mixed up at the dizzy with all that work? Check no1 at TDC and check order. Check point gap.

Graeme

[molemot]

Could well be the plug leads mixed up. Had that problem with an Alfa Romeo GTV -somebody had put the distributor on 180deg. out, so all the leads were wrong although OK by the book....that was a 2 litre Alfa engine from a scrapyard going into a 1300GTV with the low ratio rear axle - boy, did that accelerate once we got the engine firing - and thrown away the stop on the throttle pedal which was preventing anything more that 2/3 throttle!

Whatever; back to basics. Engines need fuel, compression and sparks at the right time. Petrol engines which don't work usually turn out to have ignition problems. Even when it's obvious that the fuel system is at fault, it still generally turns out to be sparks. Once you have fuel at the right sort of quantity and sparks at the right time it HAS to work, unless you have some major internal defect, holes in pistons, broken cambelt etc. Me, I still think you have a sparks problem.....

[Ray]

I think that I would go with Wayne on this one (ie: holed diaphragms and sticking pistons ) as Wayne said it only needs to be a very small hole.

You may not be able to see it just by looking you really need to hold it up in front of a strong light to see.

Ray

[Hegg]

Thanks for everyone's replies. I just obtained two carburetor kits this morning and am trying to bring my core temperature back up so I can brave the cold and go to the garage to play with it again.

In regards to the spark comments -- how can I determine if I have "enough" spark? I guess it could be something like my coil not providing enough juice or something.

Thanks again, and I'll post after I play around some more with these suggestions.

[dglotusltd]

Just to be really sure its not fule have you tried some starter fluid in the Stromburg intakes? It she tries to start then, it might be fuel.

The suggestions on the diaphrams is good. The rebuild kit will address those.

If you back to ignition, go back to basics. Ensure the plug wires are correct from the dizzy to the plugs in the correct firing order.

I experience I lot of strange stuff with my S1 (rough running, high rev stutter) until I finally replaced the coil. Suddenly everything was fine. It was indeed a spark issue.

DomG

77 S1 Esprit

[WayneB]

It wouldnt hurt to swap the coil to see if it makes a difference.

A way of checking your existing one is to pull one of the sparkplugs and with the HT lead still on ground the body of the plug, whilst holding it with some insulated pliers, then crank the engine and observe the spark.

It should be a strong blue spark and will make an pronounced crack noise.

If you are worried about it starting whilst you are doing this, pull the leads off the other 3 plugs.

Might be a good idea as well to pull out all the plugs and dry out the unburned fuel in the cylinders.

[USAndretti42]

I'm having a similar problem with my car. After a head gasket change it started and ran fine. The next time I started it up it started on 4 then lapsed onto the front 2 cylinders according to the speed drop when I pulled off each lead in turn. Cleaned the plugs and it was fine. The next day it would only run on two cylinders but this time it seemed to be the back two. They were a bit sooty while the front pair were as clean as a whistle.

I replaced the Bosch plugs with NGK's as the spark did not look great. No change. The spark was still weak even with 12 V straight from the battery to the coil. Fitted a new (Bosch) coil. The spark was no better and now it doesn't even start.

When cranking it tries to fire and when it was running on two before it sometimes spat back through the carburetters. So I am currently checking out the carbs and re-checking the ignition timing and I am going to get new plug leads. That spark should jump half an inch in fresh air so it still fires when under compression pressure. I still think the poor spark is a major contributor to the problem and a better spark will do no harm.

I would suggest getting that coil.

[WayneB]

Do you guys have a good ground strap on your engines?

Is your points gap correct?

They are a bugger to get right with the distributor where it is.

You will be doing yourselves a favour by switching to electronic ignition

Edited December 18, 2005 by WayneB

[Hegg]

Wow, thanks again! So many good suggestions!

I never got up the courage to work in the cold yesterday, so maybe tomorrow.

As a side note, my symptoms seem nearly the same as those posted by USAndretti42. I'll try putting the coil from my Elan temporarily and see if it makes any difference. Right after I re-rebuild the carbs again.

Thanks again for the expert advice!

[dglotusltd]

Be sure to use the correct coil. 3 Ohm as I recall.

Also the suggestion for the exlectronic ignition is spot on. I have a Lumination in my S1 care of the PO but I have had great success with Pertonix unit in my other 907 car (74 Elite) while I had it.

DomG

[USAndretti42]

Do you guys have a good ground strap on your engines?

Is your points gap correct?

They are a bugger to get right with the distributor where it is.

You will be doing yourselves a favour by switching to electronic ignition

<{POST_SNAPBACK}>

I'm pretty sure the ground is good. The engine cranks over well and I haven't noticed the choke or throttle cable getting hot. I have also checked the wire from the coil mounting to the clutch slave cylinder mounting bolt for continuity. Just in case, I layed the coil on the engine and ran wires directly from the battery to the coil terminals. Spark was still weaker than a weak thing.

Car has Lumenition and I changed the sensor head after I broke the chopper blade when I was freeing off the vacuum capsule. A bargain at $16 from JAE.

Anyway, a new set of leads won't do any harm (except to my wallet). Gotta get that nice, fat spark.

Edited December 19, 2005 by USAndretti42

[tonyp]

Echo that with the diaphragms, caused havoc on my Stag. Anyone care to comment on Strombergs vs UK Dellorto performance ?

[WayneB]

Not that great a lover of Luminition

Have had loads of problems with that system

They just reccomend you keep changing control boxes etc. Maybe this is why Lotus changed to Lucas Constant Energy Ignition

[watership down]

Could it be the exhaust is blocked or restricted? I had a customer in England when I worked in a garage, backed his car up to a bank and plugged his exhaust. It was a Mercury Montclair 1958 we done everything to the car,plugs checked all the ignition. Could a baffle in the silencer or cat be restricting the flow?

[Hegg]

That could be a possibility. What's the best way for me to check? Do I need to disassemble the exhaust system from the beginning and check it out?

Thanks for the suggestion.

[molemot]

It's not unknown for evil people to stuff potatoes up exhaust pipes....!

Another thought - I've found the brown connector between the Lucas sparkbox and the distributor to be a particularly unreliable thingy. All your sparks can disappear because the connectors themselves get corroded and go high resistance. Worth a look.

[watership down]

I would start at the silencer 1st then work back. Can you feel any pressure coming out of the exhaust pipe when cranking the engine?

Edited December 21, 2005 by watership down

[Hegg]

I FINALLY got a chance to work on the S1 today (Christmas Eve) and did a bunch of stuff, all to no avail.

I got a new Lucas Sport Coil from Dave Bean and installed it, took out all the plugs and cleaned them, verified the order of plug wires (1-3-4-2, counter-clockwise rotor movement), removed the carburetors, cleaned them, and replaced the diaphragms, and squirted starting fluid and nothing made a bit of difference.

The timing light is still lighting up, so I'd assume spark is still going (although I haven't taken the plugs out and physically watched the spark). I've played with the distributor timing back and forth to see if it makes a difference. Choke open, choke closed, throttle closed, throttle open, all no difference.

Fumes and such are visibly coming out the exhaust as I crank it, so I'd assume the exhaust ain't plugged.

All I ever get is a little teeny fire once every time it goes around. On rare occasion, it sounds like two pistons fire, but again, pretty weak and only noticeable by the change in cranking speed.

As far as I can tell, there's nothing wrong with the car, other than it just won't start!

AARRRGH!

(thanks for letting me vent)

[Guest teigan]

i'm probably wrong, but just so you know you have audience, have you flooded the carbs on previous startup attempts? could be too many variables at once is the stumper. it's worth measuring the exact current and voltage at each plug.

[dglotusltd]

I hate to say it but since you sprayed starter fluild in the carbs and replaced or checked the other ignition parts....it soulds like the Lumination unit has packed in.

Unless you can borrow a control unit to test, it might be cheaper to replace it with a Pertronix unit. It fits entirely within the dizzy and is easy to install. Less that $80 US.

DomG

[Hegg]

My car still has points and condensor (and the gap I've double checked), but your point is still valid. I have the old points, condensor, and all that - and it worked before I replaced it - that I could try putting back in.

As response to a suggestion, how do I check the voltage and all that of the spark? I've got a multi-meter, but it's digital, so I don't know that it would respond fast enough to read the voltage across one of the plug wires.

Thanks again, and merry Christmas!

[Guest teigan]

buy a cheap analog dwell meter. i think sears still sells them. if not you can get one online. very handy tool. plus it's made for 12-16V, so you won't have to risk your good multimeter.

[Hegg]

Hooray! It's finally started! And it's running even better than before!

I spent the holiday weekend going through the ignition system in detail. I ended up putting in most of the old ignition components at one point, and when it did start, I discovered that two of my new plugs (NGK Iridium) were non-functional.

Anyway, I think the bad plugs contributed, but I also believe that the timing was the primary cause. My dwell was only 40 degrees or so, so I adjusted that up to 62 degrees. I also had a major brain-fart in thinking that the plugs fire when the points close, rather than when they open (duh!). That was a problem when I was twisting the dizzy to try to get it lined up right to just fire at lease. So basically I was off by 45 degrees (in theory)

Anyway, once it was running, I was swapping out the original plugs (Denso) with the new NGKs and discovered that there were two bad ones. Any ideas what coulda caused that? It did run fine for 30 miles on those, and now that I think of it, I'm not 100% positive I got the correctly cross-referenced Iridium to the specified BP5ES. Either way, two plugs suddenly dying seems odd.

I've had very positive results with NGK Iridium in all cars I've put them in, so I don't doubt their quality. Maybe I got a bad batch? Maybe the 907 engine doesn't like them?