2002 955i Tiger in need of advice

[Arkansas Traveler]

This happened over night a couple weeks ago and I can't figure it out.  It is not the same issue as every Tiger's characteristically slow/double try start, mine has always had that issue.  The problem is that one morning, it just decided it did not want to start and required a lot of throttle and hesitation to keep it running, like it isn't being choked (if it had one).  It will not idle or start without giving it gas to keep it running.  It fires right up but stalls just like it needs choke unless I hold the throttle open while it coughs and misses.  I suspected the IACV and removed it, inspected it, and replaced it...it appears ok.  Tune ECU checked it and said it is ok.  I observed it move and it ran up and down correctly as far as I know.  I just remapped the ECU with 10120_Adjusted_AF.hex and reset the TPS and it still does it.  Tune ECU IACV setting is -4.  Once it is warm, it idles fine at 1220 rpm very steady and runs without issue.  It only does this when it is cold.  I've checked all of the vacuum lines and they look good.  It has no fault codes.  I replaced the battery just to be sure it wasn't part of the problem.  Is there something easy that I'm missing?  Has anyone had this problem before?  Please help, I'm pulling my hair out.


Bike: 2002 Tiger 955i stock air filter and stock exhaust
Problem: Rough start no idle when cold/start and idles fine warm

Symptom happened overnight the day after a  2000 mile 4 day trip.

No fault codes and happens with stock ECU tune 10082 and updated 10120_Adjusted_AF tune.

[metalguru]

Couple of details needed here,

What is the milage total?
When was the last time the throttle bodies were balanced?

When you say it has always had a starting problem, do you use ANY throttle when trying to start it and did you in the past.
These girlies don't like any throttle when trying to start, all it will accomplish is non-starting.
Did you check the IACV pipes VERY closely as they perish and crack in the convoluted parts, best to replace with silicon as the very last Girly will be getting on in age by now.

[Arkansas Traveler]

Thanks for the quick reply. 

Total mileage is 20,500.  The throttle bodies were balanced at 12,000 miles. 

I never used any throttle when starting before.  Now it will not start without throttle to keep it running.  After it warms up, it will start normally without throttle and idle fine.  It doesn't surge at all when warm and there is no hiccup or hesitation throughout the throttle range; no backfiring either.

I agree with replacing the IACV tubes, but for troubleshooting, if a tube was a cracked, wouldn't I have abnormal idle when it was warm? 

Whatever the problem is, it happened overnight.  It started fine everyday for 2 years until this incident.  That makes me believe it is a sensor or a vacuum leak, i.e. IACV tube, but it runs so well when warm, I can't figure it out.

I forgot to mention that I replaced the plugs, book recommended NGK, while troubleshooting and they all looked good color/temp wise.

Thanks again metalguru.

[Dutch]

Since it runs fine when warm, sounds like a faulty sensor or so to me. The bike should enrich the mixture automatically with a cold start, apparently it doesn't. I'm too new to Tigers to have a more detailed idea and the Tuono (my first injection bike) never had an issue so never bothered to dive into these things.

Good luck, Dutch

[Arkansas Traveler]

Update. 

I just replaced the IACV hoses with rubber vacuum hose.  The old plastic hose was not cracked so I guess it was at least good preventative maintenance.

Dutch, I'm moving to Geilenkirchen, GE in May and bringing the Tiger with me.  Glad to know there are some Tigers running around up there.

[metalguru]

As you can appreciate it is a bit of a problem with diagnosis when the bike is remote so there may be some strange questions to try and find the fault.

First strange one is,
Is there a reason for running the map you are?
Do you have modified exhaust and airbox?
10173 would be a better map to run and surging can be eliminated although not reported. (the map you have can cause problems). (Can send a known map to try if corrupt map is suspect)

There are 2 sensors which can cause trouble,
The engine temp sensor on the thermostat housing, it's rare but is the temp guage travelling about 1/3 up the gauge when it warms up?

The second is the airbox temp on the front of the airbox,
Has it become disconnected?
With TuneEcu is it showing airbox temp when running, it gets quite high?

Next is the Barometric hose which runs from the airbox back along the bike frame to the ECU.
It is the black convoluted plastic pipe, disconnect both ends and either with a vacuum pump or blow through the pipe with a finger over the other end and check it for continuity. The barometric diaphram must be checked GENTLY by either vacuum or sucking to detect a leak.

[Arkansas Traveler]

Thanks again metalguru for your help.

I loaded that 10120 map today to try something out, thinking that maybe it would "jog" the ECU and somehow fix my problem.  Before today it was running the same map that I assume was loaded since new in 2002.  I got the 10120 map from  http://www.tomhamburg.net/Tune_List.html .  The 10173 on that list claims it is for a different VIN than mine with aftermarket exhaust.  I have stock exhaust and stock air filter with no airbox mods.

My temp gauge usually reads lower than 1/3, just above the double hatch mark on the bottom of the gauge. 

The airbox temp sensor is connected.  I have removed and re-installed the connector about 10 times now pulling the airbox off troubleshooting the IACV.  Is the temperature reading on diagnostics page of TuneECU (not the water temp gauge reading) the airbox temp?  That reading climbs in temp as the bike warms up and has two voltage readings beside of it.

Tune ECU is displaying baro pressure.  I'll check continuity with the plumbing tomorrow.  Maybe it is reading ambient baro pressure and not airbox.  I would imagine though that it would show symptoms at higher RPM/throttle if there was a leak.  Thanks for that advice.

[metalguru]

Spot on with the airbox sensor.
Are the IACV pipes on the correct ports?
There are 4 ports but only 3 are live.

Would like to see the results of a throttle body balance as could be the usual TB to cylinder head gasket leaking, they are prone to leaks, if changing this make sure the soft cheese screws are replaced with SS. While in the TB area is to check for contamination inside the TBs will not cause your problem but nice to do.

While having the pc connected, was the TPS reset after loading the tune? What is the voltage reading of the TPS on TuneEcu? Any more than from memory .68V then replace, good to replace if TBs have to come off to replace gasket.

The later tunes run a treat in earlier bikes but not vice versa.
If you are in the airbox it is a common mod to remove the baffle inside, if plastic with a hot knife/soldering iron or if metal pull it out and drill another intake hole in the front of the airbox opposite to existing and fit the snorkel so it covers the temp sensor. Not vital mods but the running is better.

[Dutch]

Dutch, I'm moving to Geilenkirchen, GE in May and bringing the Tiger with me.  Glad to know there are some Tigers running around up there.

Cool, that is really very close to where I live. We can meet up and I'll show you some really nice roads just a little south of that in the Eifel.

Bit off-topic but nevertheless: can you run the bike on a US plate? Germany is one of the stricktest countries in Europe when it comes to the technical state of a vehicle. All modifications need to be approved and it can be quite a pain to get a bike that has been modified on a German plate. On the positive side: Holland is not so strickt, so we can always get the bike a Dutch plate and flog it. Tigers are a bit more expensive here than in Germany, so proceeds should allow for purchase of a German bike with Tüv. To illustrate: mine started it's career in Germany as well.

[Arkansas Traveler]

Hey Dutch, I just PM'd you.

metalguru,

The IACV pipes are on the correct ports.  I only removed/replaced one at a time to ensure they didn't get mixed up.

I reset the TPS before updating the tune, it didn't fix it, and again after the new tune, and still didn't fix it.  It has the same exact issue with both maps.  The TPS voltage is .61V.

I checked the baro hose for continuity and it didn't leak.  I'll  run a rubber hose to replace that brittle plastic line soon. 

I like your thinking about a throttle body gasket leaking.  One of the intake valves that you can see when looking down the throttle bodies is much cleaner than the other 5 valves.  It would be the #1 cylinder inboard/right valve.  I wonder if it is sucking air over that intake port.  Is that a sign of a gasket leak?  I attached a picture of that intake port.

Thanks again for all of the input. 


**Update**

I sprayed throttle body cleaner all around the throttle body while starting it and after it was running and there was no change in RPM, telling me that the gasket is sound.

All I can think of to do now is swap out the TPS and stepper motor even though Tune ECU says they are ok.  I'll have to order the parts. 

After the bike warms up (about 1 min), everything is fine.  Starts right up with no throttle and idles perfectly. 

Input is still very welcomed.  Thanks again.

[metalguru]

Looks very much like the gasket is leaking.
When replacing use a good gasket sealer like 3bond or blue Hylomar and just a smear.
It will be a good time to replace the screws for equivilent SS.
When balancing the throttle bodies use good quality gauges, the balance has to be exact, confirm the balance with feeler gauges between the butterflies and bodies. Then carry out set up and trims as per TuneEcu instructions.
Make sure the IACV is clean and cycles fully not forgetting the foam gasket. Confirm correct adjustment via 'blip' test.

While you have parts on order and bike is apart it may be a good idea to run through the shims to ensure all is good, they don't often need adjustment but the milage is right for a check up.

[Timbox2]

I once had similar symptoms, wouldn't idle cold, fine once warm. In my case it was a faulty stepper, or to be more precise, it was after I stripped the stepper to give it a clean, and as Bixxer is also aware this is not a wise move in a dark garage. A new stepper did cure mine, but obviously cant say for sure if its the same for you.

[Arkansas Traveler]

Thanks Timbox2 for the input. I'm ordering a new stepper and TPS and see how that goes. That makes me feel a little more settled to hear someone else has had a similar issue.

[Bixxer Bob]

I'm slightly at odds with MG here despite us agreeing on most things and more in line with Tim. As it runs ok hot, but not starting or cold, my money is on stepper motor in IACV being stuck in the hot engine position. We'll see eh?

TuneECU IACV test would soon show if it is.

[Arkansas Traveler]

I ordered a stepper motor that should come in by the weekend. I'm going to be out of town for the week after it arrives so it'll be a couple weeks before I update the status.

I'm betting on the stepper motor and it was my first idea of the problem. However, I checked it on Tune ECU and with MotorScan professional diagnostics that a buddy let me borrow, and they both cleared the stepper as having no issues. I observed the stepper motor run its startup BIT when turning on the ignition and it appeared ok so I began looking elsewhere. I'm just throwing parts at it now and The stepper is my first choice.

I will share the results of the stepper swap. Fingers crossed.