Cold Start Issue

[guzziart]

Hi All,

I have a '03 V11 Lemans that I perceive to have a cold start issue.  The process requires more than "choke" on and hit the starter button (cranks fine)....the bike will try to start/run but quickly stalls, usually the 3rd-4th attempt the bike will start and remain running.  In order to get the bike started on the 1st cold start attempt requires "choke" & that I twist the throttle during cranking.  Do you have to do the same with your V11's??

I thought this cold start issue would resolve itself after performing the following but the condition still exists:

Head retorque, valve clearance adjustment (0.004/0,006"), new plug wires, caps & plugs, new battery, TPS reset (157mv), TB sync (idle warm approx 1170 rpm), set CO to zero (was -15), new air filter, fuel filter & lines, capped off TB ports from fuel canister, checked for intake leaks, oil & air temp sensors appear to be working (oil is at ambient air temp until engine warms and then rises accordingly).

The bike has stock headers & crossover but M4 mufflers.  Aside from my cold start issue, this bike runs great.  I have not tried playing with different CO settings....maybe I should???!!!   I realize that this bike does not have the most sophisticated FI out there but thought that I should be able to high cam the throttle, hit the start button and have it roar to life.  

Anyway, thanks for reading, your thoughts, comments, suggestions  & experiences are greatly appreciated. 

Art

.

[docc]

So, yes, I gradually roll my throttle on for start up. Typically fires third or fourth compression.

Also, consider valves at 0.006/0.008 and set your high idle cam so it just has clearance with the linkage when off.

Otherwise, looks like you have done a lot of things right!

[Bastiaan Sponton]

Is your choke not sliding back? To off?


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[gstallons]

Now , explain your tps setting . Did you set this at COMPLETE closed throttle plate ?

[LowRyter]

4 hours ago, docc said:

So, yes, I gradually roll my throttle on for start up. Typically fires third or fourth compression.

Also, consider valves at 0.006/0.008 and set your high idle cam so it just has clearance with the linkage when off.

Otherwise, looks like you have done a lot of things right!

You know I was using the other specs, 004 and 006.  Today I am putting plugs in my Corvette.  The plugs were pregapped to .040 and my feeler gauges couldn't enter the gap, not even .035.  I had a sparkplug gap tool and sure enough .040 measured on it.   

If the rest of my feeler gauge is as bad as that, I might be gapping .006/.008.  Heck maybe .010+ ?

[LowRyter]

Well now there's more.  I changed out the plugs on the 'vette and half of them had burned the bottom electrode off.  No wonder I felt an ignition skip when I was in high gear.  These are supposed to be 100k miles with only 75k on them.  The replacement plugs were a different part number.  Advance Auto parts says the old part DOES NOT fit my car.  

<shrug> 

I am very tempted to post WTF.   (just joking)

[gstallons]

I hope you are installing AC Delco (premium) spark plugs ? AC changes #s when they go to a different electrode plating on the center / ground electrodes and other improvements . 

[guzziart]

17 hours ago, gstallons said:

Now , explain your tps setting . Did you set this at COMPLETE closed throttle plate ?

Hi G,

Sync rod disconnected, confirmed clearance between throt plate linkage & fast idle cam, cleaned carbon from TB's that effected full closure, set tps using break out harness & VOM.

Art

[guzziart]

19 hours ago, Bastiaan Sponton said:

Is your choke not sliding back? To off?


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Hi BS,

Confirmed that the high rpm cam is not inadvertantly backing off.  Apparently there is plenty of friction up at the handlebar choke lever to overcome spring tension at the cam.

Art

[guzziart]

20 hours ago, docc said:

So, yes, I gradually roll my throttle on for start up. Typically fires third or fourth compression.

Also, consider valves at 0.006/0.008 and set your high idle cam so it just has clearance with the linkage when off.

Otherwise, looks like you have done a lot of things right!

Hi Docc,

- Yeah, if I gradually roll on the throttle while cranking (when cold), the bike will immediately start & run and I have no complaints with its performance afterward.

- I wonder if diminshed lash results in a too lean condition for cold starts??  But if you're encountering the same at cold start, I'm a little inclined to bump up the CO Trimm by +5 to see if the condition changes.....Thoughts?   It was originally at -15 and is now zero.

-  "set your high idle cam so it just has clearance with the linkage when off"  Confirmed!

OK, so I'm grasping at straws here but has anyone experienced injector issues...carboned up, leaking, etc.?   If so, does additives like Seafoam, etc. seem to cure anything?

Art

[LowRyter]

4 hours ago, gstallons said:

I hope you are installing AC Delco (premium) spark plugs ? AC changes #s when they go to a different electrode plating on the center / ground electrodes and other improvements . 

ACs came out, ACs went in.  Iridium (delirium?), $9 ea.

I assume the old plugs were OEM, since they're "good" for 100k miles.  Car was running doggy in top gear, felt like a typical ignition fault, (wire or plug). So I did one side of the engine and discovered one burned plug and had "aha"  moment and drove it.  It seemed a little better but I was only lugging it in town, not on the highway.  Then I did the other side and found three of the four were burned.  After replacement, the car does indeed run better.  

First I checked the air filter and it was really clean.  Then I inspected the MAF and took out the throttle body which was also quite clean.  So then I bit the bullet (Guzzi content) and paid $150 for wires and plugs.

Anyway, I can't trace the lineage of AC part numbers.

(sorry about the thread drift)

[gstallons]

2 hours ago, guzziart said:

Hi G,

Sync rod disconnected, confirmed clearance between throttle plate linkage & fast idle cam, cleaned carbon from TB's that effected full closure, set tps using break out harness & VOM.

Art

You synched the throttle bodies and adjusted the l.h. idle screw to get 0.540 mV on the tps ? I assume the air boots from the throttle bodies to cylinder head are in perfect shape ? I am having the same problem and find my air boots are cracked . I am getting new ones and hope this will cure my problem(s) . Mine cranks forever and when / if it starts , the plugs are wet and the engine misfires . BTW , my bike has been PERFECT in the past and this season I am scared to ride it past the driveway .

 Chevron makes the best fuel injector cleaner to go in the fuel system 

[guzziart]

Hi G,

I used the LH idle screw to get 1100rpm idle and did not use it to set tps, at idle the tps is 451mv, Throt 2.84 degrees, temp 88c.  I sprayed wd40 between TB's & head to detect leaks but no change in rpm was detected.  I have also rechecked the closed tps value, it is still 157mv.

I could crank the LH idle screw in until I reach 540mv (I'm not opposed to to trying it) but the idle will be substantially higher.   What is your idle rpm set to?

Thanks,

Art

 

[docc]

Yeah, your idle is too low. Is that the 1100 RPM from the tach or guzzidiag?

The spec is 3.6º/540mV with some range. Honestly, once everything else is right, you can set the idle speed across a broad range depending on what you, the conditions, and tour set-up like.

The looser valve lash won't make it leaner or richer, but you may find the idle more stable.

[gstallons]

Hmmmm. IDK what the idle speed is when the TPS angle is 0.540v .

You should adjust idle speed w/the idle air bypass screws . Don't concern yourself w/watching a tach needle to get the idle speed you want .