unusual problem with gsxr 600 engine

[KMan]

hello ! We are using a suzuki gsx-r 600 kg model engine this year. i have wired the wire harness properly and all the sensors also were seeming to be working fine. when i start the ignition circuits the fuel pump is priming properly for around 3 seconds which means the tip over sensor is also fine. The engine is also cranking fine. I checked the injectors and all the primary injectors are working fine while cranking. i also checked the ignition coils individually by attaching spark plugs externally which also were working. Inspite of all this the engine refuses to fire. I never opened the engine ,so there is no possibility of any disturbance to valve timing. I have not taken out and checked the spark plugs inside yet, but is there a probability of all plugs going dead at the same time ?
please help asap !!!

[KMan]

hello ! We are using a suzuki gsx-r 600 kg model engine this year. i have wired the wire harness properly and all the sensors also were seeming to be working fine. when i start the ignition circuits the fuel pump is priming properly for around 3 seconds which means the tip over sensor is also fine. The engine is also cranking fine. I checked the injectors and all the primary injectors are working fine while cranking. i also checked the ignition coils individually by attaching spark plugs externally which also were working. Inspite of all this the engine refuses to fire. I never opened the engine ,so there is no possibility of any disturbance to valve timing. I have not taken out and checked the spark plugs inside yet, but is there a probability of all plugs going dead at the same time ?
please help asap !!!

[Kirk Feldkamp]

Many times when a fuel system is completely drained, it takes a little bit to get the air out of the lines. It generally won't happen without deliberately priming the system. With an aftermarket ECU, this is usually achieved by running the fuel pump and cycling the injectors on a test screen until you hear the tone of the clicks change. In this case, you don't have a lot of options unless you get creative. How long have you tried cranking? Do you smell gasoline (strongly) out of the exhaust when you're cranking? Do the plugs show any sign of being wet with fuel? When you crank, does it just crank and crank and crank, or is it popping and banging sounding like it's trying to start but can't?

Silly question, what throttle body are you using to try to start it with? How do you know it's adjusted properly?

[KMan]

I am using all the original parts which came with the engine, no aftermarket parts. Even the throttle body is stock ! I have cranked till one whole battery has completely discharged. I was checking voltages and resistances of sensors and then cranking after each check, so eventually the battery discharged. I hav not yet checked if the spark plugs hav become wet, but that is quite possible after such a lot of cranking ! There is no smell of fuel in the exhaust at all ! Would opening the cylinder head and giving it a clean up help ?

[KMan]

and this problem has started few days back, the engine was firing properly 10 days back ! Even now sometimes just one or two cylinders fire sometimes but then again it all stops !

[Kirk Feldkamp]

There are many electrical components that require a particular voltage range to operate correctly. Most ECU's will have some voltage compensation for injectors and dwell and such... but it can only compensate for so much. It's common for ECU's to simply stop firing the injectors or ignition if the voltage is too low. Lower voltages can also effect the ability of the ECU to sync while cranking. If you're ever in need to long cranking to get it started, it's advisable to get a larger car battery, possibly in combination with a battery charger, to increase your cranking capacity. If you're seeing cranking voltages below maybe 11V on your current battery, then it's probably toast.

[KMan]

alright....lower battery affecting the ECU synchronization is a new piece of information, thank you. But yesterday i used my own larger car battery, which was fully charged on 12V. The sensors were then also showing voltages as per given in the service manual. Somehow I think it is the wet plug problem, but not very sure! Still i ll try plugging in a new battery, jus to rule out a possibility . Thanks.

[revolutionary]

Start by installing a brand new set of spark plugs.

[Owen Thomas]

If you're running an aftermarket ECU, which I'm assuming you are, STEP ONE is to verify your base timing with a timing light. Calibrate it as necessary, then when you're absolutely sure it's correct look into other options. As Daryl said, it's likely that you'll need to replace your plugs if you were attempting to start the car with timing off by more than 50 degrees.

[KMan]

i am so srry for the late reply. it was the wet spark plug problem, and its sorted now. Thanks a lot for your help guys, really appreciate it !

[Kirk Feldkamp]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by KMan:
it was the wet spark plug problem </div></BLOCKQUOTE>
WINNER! If you guess enough things, ONE of them is eventually right! http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

[Tallboy]

Also, thanks for the followup. Too often these problems seem to go unresolved, so it's good to see a confirmation of successful results.

Good luck with the making of the horsepowers and the torques!