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marcbria

Timing belt reinstalled

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Hi Everyone,

 

So the last major work I was doing on my Series 1 in August 2012 after getting it to idle for the first time, was replacing the timing belt. This fun job led me to discover that my IN/EX Cam sprockets were several teeth out of alignment and that the timing belt tensioner had been completely un-tensioned.

 

Removing the old tensioner revealed that it had clearly been rebuilt by someone at some point. I ordered all the rebuild parts from SJ Sportscars as it had some evidence of corrosion on the main bearing and I figured new springs couldn't hurt. I ordered the parts in August and thanks to the wonderful postal system shipping the parts back and forth to England received them in a timely manor in November. Next I discovered that my old tensioner had been sleeved and the new plunger didn't fit and that further more the reason the tensioner wasn't tensioned on the car was because the sleeve prevented the screw from going in... Upon discovering this I gave up on the rebuild and bought a refurb from Lotusbits.com. It arrived in December and by February I had it installed, sigh.

 

Not to worry I used the time in between to sort out some electrical stuff and rip out the old radio and a TON of duct tape that had been used to install it... really duct tape and in two fun varieties old crusty that falls apart and old gummy that leaves everything it touches sticky.

 

As for the IN/EX sprockets, I suspect that they jumped some teeth due to the loose tensioner but can't say for sure. I've realigned everything to TDC, installed a new timing belt from JAE with the rebuild tensioner from Lotusbits.com. 

 

I turned the engine using the starter with the plugs pulled and nothing jammed so I haven't inadvertently caused a interference situation. I next did a cold compression test that gave very similar results for all cylinders, so at least I have compression.

 

Next step I'm going to try and start it.

 

Brian

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Good luck, Brian!

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Good luck indeed.

 

Brian, BTW - what figures dig you get with your cold compression test? Just wondering as I did a cold test, and got 50-60 psi just turning over by hand.

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Thanks for the encouragement,

 

I tried starting it last weekend and it didn't catch. The fuel pump kicked in and ran until the system reached pressure and then I cracked it a while but it didn't catch. I pulled the spark plugs after and the plugs for cylinders 1 and 2 were dry while 3 and 4 were wet with fuel. This leads me to believe that I have a carburetor problem. I have Strombergs installed at the moment with no air filters. When I push the pistons in the mouth of the carbs up to reveal the pins they are both wet with fuel so I'm not sure why I'm getting more fuel in 3 and 4 than 1 and 2. Last year when I had it idling I did notice that 1/2 were drawing less air than 3/4 but I didn't worry about it as I wanted to get to the timing belt.

 

I suspect there is a combination of things going wrong here. My gut is telling me that cylinders 1 and 2 are starved of fuel and 3 and 4 are flooded. I don't think spark plugs wet with fuel will fire but I'm not sure, anyone know for sure?

 

My next test is to pull the high tension lead from the coil to the distributor, hold it to something grounded and see if I get a spark while cranking. I was cleaning up the electrical around the optronic so its possible I disconnected something without realizing. I noticed that the coil was pretty hot considering I had only been cranking the engine, is it normal for the coil to be hot? Maybe if I disconnected part of the optronics controller the coil was charging but never discharging.

 

Brian M.

 

P.S. Sir Paolo, I ran 3 tests on each cylinder and got readings between 75PSI and 100PSI with all averaging around 85PSI

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Thanks for the compression figures, Brian.

 

It looks like the most important element of the test is the temperature of the engine.

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Little update,

 

I pulled the high tension leads to the spark plugs and held one near the manifold while turning it over and I have a spark so its no an ignition issue. So now I'm thinking its a timing issue as I have fuel, spark and compression.

 

I read another thread on this topic but I'm still not sure, with the fly wheel at TDC and the IN/EX sprockets aligned, where should the rotor arm in the distributor be pointed? To the lead to cylinder 1?

 

Brian

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Yes, it should.

If you're having trouble starting, you could get someone to crank it over on the starter with you gently turning the dizzy a little bit until the engine catches.

 

BTW - looking at your earlier post, I notice that you are running on Strombergs. These carbs do suffer from diaphram splitting, which cause all sorts of problems. So it might be worth investigating.

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Hi Paul,

 

I rebuilt the Strombergs and replaced the diaphragms so I don't think thats whats going on here. I've taken the distributor cap off while at TDC with EX/IN lined up, I have a Lumenition distributor and it seemed that the optical sensor wasn't completed occluded with the little 4 way blades so I rotated the distributor so it complete covered it.

 

I also dumped out the fuel from the float chambers it was pretty orange so I'm thinking it was bad. Gonna go try and start it again with these things looked over, hopefully it will start right up and I can move on to tuning!

 

Brian M.

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Hey All,

 

It started! First time in 2 years. Couple of rough sputters on the first crank, cranked again more sputters ... then thought hey this things got a choke for a reason what the hell. Pull up the choke, crank it and vroom! Let it idle for a good 15 minutes.

 

So on the first run I've found a few issues:

- Can't get the idle below 2000rpm

- Theres a lot of smoke coming from around the exhaust manifold so I'm thinking it might need a new gasket or it might be cracked or maybe the air injectors that have been removed aren't properly sealed.

- The temperature gauge had worked its way up to about 3/4 or 4/5 of the way up but not into the red. I checked that the fans were on and they were so I decided I better shut it off just to be on the safe side. Came around back and steam was pouring out of the coolant reservoir! Not sure whats going on with that.

 

Brian M.

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Great news on getting the beast started again!

Could be all manner of things after 2 years of inactivity. The idle might be down to the bob weights in the dizzy getting stuck. I had this problem and had to free them with WD40. Running hot could be due to swarf in the system- are all cooling pipes hot or are some cold? Especially to the heater.

Good luck!

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Hi Paulo,

 

I just replaced the timing belt and tensioner so I'm thinking maybe when I refilled the antifreeze I got an air lock somewhere in the system and when I started it up the bubbles cleared and the level in the reservoir dropped. I didn't think to check while it was running but I've topped it back up. I'm gonna check it more closely the next time I start it up.

 

Brian M.

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Hi Brian, yes and often overlooked when refilling the coolant is to set the heater controls to hot otherwise you'll likely get an air lock here.

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So after topping up the coolant, I tried starting it again today. Caught on the second try nice and solid, kept an eye on the coolant levels which stayed stable and the temperature never rose above 1/3, so much cooler than last time. I'm fairly certain it was an airlock now. Also no exhaust leak?! So I'm thinking it may have just been oil residue burning off maybe something from an old leak. The RPM also a settled down around 1000RPM once I took the choke off.

 

Next I discovered my fuel pump has developed a leak and was merrily squirting gasoline under my fuel tank down and out the drain holes and ... into my tool box :o  maybe a liter of fuel in the box by the time I noticed it! Old rusty think dribbled it all over my driveway when I moved it outside to help air the place out. I set some fans up to air the place out.

 

So two steps forward ... one fuel pump back! But if my biggest issue is replacing the fuel pump I'm pretty pleased, except for the mess, stinks like petrol :sick:

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This is all good news Brian! All the joys of bringing a car out of hibernation eh?

Might be a good idea to also check all the earth points too. I found they needed cleaning after a similar period without running (the Lotus, not me :))

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