Triumphrat

jvx800

I have a 98 T595 that is back to rough idle. The only error code I receive is the MIL 1601 open ground. I just read about the ground block so I will be taking care of that issue promptly. Here is the issue:

First couple of days it seemed to be fine. Now it starts and runs but has a rough idles and after 5 minutes will die. Bike has hesitation from idle when trying to rev but eventually catches.
I have performed the following -
1) replaced and checked the IAC to throttle body hoses to fix any vacuum leaks.
2) replaced the IAC o-ring
3) TuneEcu IAC test works - hear the slide moving.
4) cleaned the tank including new filter.
5) tightened the throttle body bolts to prevent vacuum leaks.
6) Closed one drain line on the airbox at the rear but this made no difference. (Not the vacuum line to the fuel regulator - this is still connected.)
7) had loaded the TuneEcu map for high mount exhaust but i forgot to write the number down - will check
8) tried to run the TPS Reset but the bike dies after about five minutes and will not complete the process without manual throttle assistance. Idle drops to 1050-1208rpm and eventually dies.
9) TPS shows 0-69% WOT
10) voltage is 5.7 at idle for the TPS.
11) TuneEcu fuel pump test works

How can I get this bike to idle long enough to correctly set the map? Any suggestions? My first bike with ECU FI and am sorely missing the jets, needles and screws on my other bikes.

DEcosse

1601 would suggest an issue with the MIL light itself - is it not coming on? (should come in with ignition before you start)

8) TPS reset is not done with engine running!!!
9) that is normal
10) think you mean 0.57V - again normal

First, make sure you have selected compatible tune for your VIN/model.

Most likely you need to adjust (increase) the CO setting (aka idle fuel trim) - especially with Ethanol Fuels this is probably necessary.
That is on the 'tests' page - bike needs to be over 85 C to become active and is real-time adjustment with the engine running.
Do the TPS reset (ignition on, not running) before you do that. Be sure you have most current version of TuneECU - there was an issue with the TPS Reset in one of the recent down-rev versions

__________________

bradtx

jvx800, For item 5, did you loosen all of the screws for the two rails that join the TBs together before tightening the TB's mounting bolts? If not you'll need to in order to prevent any vacuum leaks at the TB bases...worth checking the TB gasket also.

Is the engine backfiring when you blip the throttle? If so it's an indication of a lean mixture caused by a vacuum leak, a lack of fuel pressure, fuel volumn or both. The wrong map can also cause a lean condition, but as always rule out anything physical before changing the map or anything in the map.

On the other hand, if you smell gasoline the mixture is rich, which if severe enough can foul the spark plugs which will cause hesitation without any backfiring (usually).

Brad

jvx800

I did not loosen the TB rails before tightening the TB base bolts. I will try that this weekend.
The map that I have loaded is the TuneEcu #9860. The bike has stock airbox with K&N air filter and high mount Scoprion pipe. Rear wheel sensor is on the bike.

I will try the Idle Fuel Trim adjustment and see if that helps.

jvx800

Finally resolved! I decided to start from the fuel tank and work my way forward from the fuel to the throttle body. When I pulled the fuel pump out to inspect the filter, I found a small split hidden on the back side of the short connection hose to the filter. I replaced that thinking that I was losing pressure even though I did have fuel flow from an earlier check. I put everything back together and the bike fired up the first time. So it was lack of fuel pressure that was the culprit. Now I will be able to test maps till I find the best fit. Thanks for the suggestions!

bradtx

Congratulations!