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Discussion Starter #1
05 naked w 4k miles and needing some help here....

the bike starts easy but wont idle and runs crappy until the bike warms up then pull hard and runs great and idles right at 1250 after I blip the throttle long enough to get it completely warmed up. not neccessarily just when temp guage shows 180 or so degrees but physically the engine or an electrical part because i can shut it off and start it again in a couple mins and it runs like crap again and has at least 150 degrees showing

the coils are showing 6 ohm between the 2 legs and 27k between positive and sparky cap. 2 -5ohm according to manual and the secondary is 24-37k


It doesn't have a programer also.


could this be a fuel issue? PO had a new fuel pump put in for some reason and it does prime for about 5 or so secs when I turn the key. Just seems like somethings warming up and making contact
 

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Discussion Starter #2
also the front spark plug when I held it to the chassis was yellow and not as strong as rear. new ngk's I gapped and put in myself
 

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To fix your crappy cold starts, I'd do a Fast Idle Adjustment (section 5-32 in the service manual). It mainly consist of setting the TP sensor output voltage to exactly 1.21 V. I bet yours is way off.
Once that's done I'd check all the following, firstly the vaccum hoses (work your way up from the bottom of the list):
 

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The fast idle system for cold starts works off the STV actuator, it pushes a cam which opens the throttle a little. It's entirely triggered by coolant temp, so it sounds like yours is off.

First, I would tweak up your hot idle speed a fraction to 1300 - 1350rpm, 1250 is a hair low. Then don't mess around with measuring voltages etc for the fast idle setting, just tweak the fast idle screw a tiny bit clockwise. You'll need an angled screwdriver or a right-angle driver.

In sub-50F temps, I found my K6 SVS was stumbling and chugging from a stone-cold start in the morning, and would need a little blip on the throttle to get it firing evenly. It would then idle smoothly at around 1600 - 1700rpm (hot idle was 1300rpm).

I gave the fast idle screw a tiny adjustment clockwise - I mean literally no more than 1/12th of a turn - and it sorted it completely. In the same ambient temps, the engine now bursts into life immediately with no stumble or chug, and idles at 2200rpm for about 5 seconds, then gradually dials down as it warms up. No need to massage the throttle.

So tweak the screw gently - even 1/8th of a turn may be plenty. The adjustment is very sensitive.
 

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Discussion Starter #5
Thank u both for chiming in.... I installed 2 known good coils and crappy cold start/running situation remains unchanged. Set the TPS to go to top at about 1450. still no change.

I'll look into the advice provided and check for vacuum leaks and look at ballalncing the throttle bodies. Bike has some specs of rust in tank and PO installed a fuel pump. I'll have to check the flow coming out of it also I guess. Possible the injectors clogged?
 

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Discussion Starter #6
Also want to add that when the bike does fire up it doesn't high idle when I get off the throttle but goes to the Hot idle setting rpm's
 

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Thank u both for chiming in.... I installed 2 known good coils and crappy cold start/running situation remains unchanged. Set the TPS to go to top at about 1450. still no change.

I'll look into the advice provided and check for vacuum leaks and look at ballalncing the throttle bodies. Bike has some specs of rust in tank and PO installed a fuel pump. I'll have to check the flow coming out of it also I guess. Possible the injectors clogged?
I made a dealer tool and set the tps to go top of dash as per manual.
 

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Discussion Starter #8
4) Disconnect the IAP sensor coupler .
1
5) Turn the ignition switch ON .
6) Measure the voltage at the Red wire and ground .
If OK, then measure the voltage at the Red wire and B/Br
wire.


while waiting for my carbtune delivery to sync the throttlebodies I tested the iap sensor plug and found the b/br wire didn't show the 5 volt reading like the red to ground wires. I needle probed the same wire back at the ecm harness and got same reading. could this be my issue? How would I go about verifying if its the ecm or harness if so?
 

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... found the b/br wire didn't show the 5 volt reading like the red to ground wires.

... I needle probed the same wire back at the ecm harness and got same reading.

... could this be my issue?
Try test again but make sure the kill switch is Off and the bike is in Neutral.

Kill switch On or bike in gear with the side-stand down will kill power to the ECM and thereby no voltage on B/Br.

A true voltage failure on B/Br (main sensor power) would cause a red light in the dash and trip all FI sensor error codes.
 

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Discussion Starter #10
pulled the tank and gas wouldn't stop flowing out of pipe when I undid the fuel coupling. flipped the tank over and switched the pump with another a buddy had and it roared to life. stone cold start it went to about 3k rpm then quickly came down to 1500 and idled perfectly. Took it out and it rode great. Thanks for all the help and I'll start dialing in this beauty asap.

I is one happy rider
 
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