Help with Diagnosis

[chunngle]

SERT as in Laptop with black or orange colored dongle and being able to look at live data?

Does that 30 seconds of "ok idle time" happen only from a stone cold engine or will you get that grace period even when the motor is hot and at full temp.
Have you already checked or replaced the spark plugs and spark plug wires.

Yes it is a SERT with the dongle. I could hook up to a laptop if I only knew exactly what I was looking for.

The 30 second grace period seems to happen most often when the motor is cold. Actually I have not really run it enough to notice whether it does it hot or not. I am so concerned with the way it is not running good.

Replaced the plugs. Old plugs had about 1500 miles on them and looked to be on the slightly lean side. Although fuel consumption really (EDIT) and thought they would indicate a rich condition.

Checked plug wires 6500 ohms on rear and 8300 ohms on front

Please read and understand the info in this link...

A Friendly Reminder - Harley Davidson Community

 

[Hoople]

This will tell you if the problem is ignition. Go to Napa and purchase one of these spark tester tools. (see attachment)

Place it in SERIES with the Front spark plug. (not in PLACE of the front spark plug) Set the gap on the tool to .020".
The coil must now jump the combination of both gaps (both test tool and front spark plug). Start the engine and watch the tester gap closely. When the front cylinder starts to miss fire, does the tester gap stop sparking? If it does, you know it is ignition.

If the tester spark gap continues to jump even when with the engine miss-firing, swap the two injectors. Clear the error log of any DTC codes. Start the engine and see if the P1353 changes to P1356.

Should have asked before,,, When the engine miss fires at idle, do you smell raw fuel coming out of the pipes. If you don't, I suspect a bad injector/or injector not being triggered.

I would perform the ignition test 1st before anything else.

Also forgot to ask if you checked the charging system regarding what TQ recommended. Is the voltage falling much below 12.2 (across battery) when it starts missing. I really don't know how much charging output can be expected from a single phase system at idle. (?)
Not that familiar with expected output current since my bike is not single phase but it should at least keep up.

 

[chunngle]

OK, conducted the spark test and has good spark at all times. The charging system checks all checks out good. Voltage drops from 13.3 to 12.9 volts during the miss. I didn't think that was too bad. I switched injectors and so far no code P1356.

I did find a problem and sure have my fingers crossed that it is "the" problem. I retraced my steps in the fuel tank after a suggestion to check the plastic pressure regulator adaptor because they tend to crack and leak. I popped the top off the tank and turned on ignition and sure enough it is leaking when the fuel pump primes. I will address this in the morning and see if it is the cause of all problems.(note to self....put fuel pressure check at top of list next time).

I have my fingers crossed because I have not found any problems electrically. At least all connections got a good cleaning.

 

[Hoople]

I hope it does turn out to be low fuel pump pressure. To me it sounded more like an ignition spark issue (front coil or ion circuitry) or a bad injector and I'm surprised it was not.

Keep us in the loop of what you find. Having to made a fuel pressure adapter for just a couple of readings is a pain.

 

[chunngle]

OK,,,,thought i had conquered the demon. Changed out regulator housing in the tank. The bike fired right up and idled smooth. Took it out for a short ride and it ran GREAT! No missing, idled smooth at the stoplights, very good acceleration. Stopped for gas after about 10 miles and it was hard to start. Had to give throttle to get started. Still idles smooth and runs great. I get home and check codes and the same P1353 code (I had swapped out front and back injectors last night). Started back up and hard starting but idles good and no missing. Reset the codes and going out for another ride to see what it does and if it throws the same code again.

 

[Hoople]

It is only a crude test and really does not tell you what you really want to know, but disconnect the crank sensor and read the resistance of the sensor with a meter when it is stone cold vs when it is hot. (hot resistance vs cold resistance).

Also measure the AC voltage output of the crank sensor (disconnected from wiring harness) while cranking the engine when cold vs when hot. The AC output of the sensor is a function of crankshaft speed, so once the engine is running, a low output signal will be hidden. See if the output falls when the sensor is Hot vs when it is stone cold. You want a fat signal when cranking.

The front cylinder is phased off the missing teeth of the crank flywheel. It almost sounds like the ECM is now having a difficult time determining phasing of the front cylinder due to a marginal or low crank sensor signal. Hence the P1353. Once you get all 4 readings, you may want to check for ferrous fuzz metal on the end of the pickup.

 

[harley@16]

do you think the idle air control motor can cause some of these issues, maybe worth a check?

 

[chunngle]

OK got home from ride. Put on about 50 miles. Made three different stops. The bike fired right up and ran great from home to first stop. Fired right up and ran great after first stop which was a longer stop so the bike had time to cool down. Hard to start at short second stop when bike was still hot but ran great. Hard to start at third stop and bike was still warm. Ran good and idled good. The engine light came on while getting on it hard on the freeway on ramp. Checked for codes when I got home and the first set of codes where I had been getting the P1353 now got "no Rsp". It almost seems heat related or intermittant like ignition switch related????? I will ride it more tomorrow to see how it does.

do you think the idle air control motor can cause some of these issues, maybe worth a check?

Actually it reminds me of issues I had with the Daytona Twin Tech auto tune unit when I had it on and it would point to the IAC quite often.

 

[maine-e-axe]

Check the gas tank vent line for kinks or when it's running bad loosen the gas cap to see if it sucks air and smooths out. just a thought.

 

[chunngle]

well after a good 75 mile ride on Sunday and another 50 miles tonight it seems like the fuel problems cured a lot of the rough idle and running. It still has the problem with hard starts and seems to run a little sluggish when it gets warm. There is a raw fuel smell while it is cranking before starting. It is still throwing the P1353 code at each ride. I am at a loss here.