Electrical Fault Or Something Else (causes Low Voltage On Start-up)

[GTS4-32]

Hey guys, im driving a r32 gts4 and have problems starting the car when its cold, it struggles to start on its own. I have to pump it gas a couple times until it starts. The previous owner had told me, that he was told it was an electrical fault. I thought id ask here before i go anywhere first to have it chekd out. Can anyone help me out and explain what i should be looking at or if anyone could solve the problem? Would be much appreciated.

Thanks

Steve.

[J_Red33]

Is the starter actually struggling to turn the engine over? If so you've probably just got a weak battery/old. Get the cells checked if this is the case to see what they are like, or if you have a multimeter check what voltage the battery is reading when the car hasn't been running for at least a couple of hours.

Can of worms this one unless you can give us more detail, lots of things make a car hard to start, but low battery power is always a good point to check first.

[GTS4-32]

Sorry forgot to mention the battery is brand new and reads at about 13.4 when started. So its definatly not the battery. Thats why im asking what else it could be. As i said the previous owner belived it to be an electrical fault, but where would i look to fix this problem?

[J_Red33]

Electrical faults can be a real pain in the ass if it is one & not easy to find for anyone untrained in the electrical field (it's scary how little even numerous autoelecs know sometimes).

If the starter is turning over fine you've then got to look at spark and fuel. If the car runs fine I'd say your spark is ok, but I wouldn't rule it out completely.

Do you get a real petrol smell when you start the car? If so it could be leaking fuel injectors that are slowly emptying all pressurised fuel into the plenum, but really you need to take the car somewhere to get it checked out if it's becoming an issue. Could be any one of a number of reasons

[GTS4-32]

Yea i was planning too take it into somewhere to have it checked out.

Well the spark plugs have been changed recently and i dont smell fuel when i start it. Everything seems fine.

I thought id ask here first before taking it in, just incase you guys could help me out with solutions. Thanks for your inputs so far though Jared.

Steve.

[blind_elk]

According to the workshop manual, difficulty cold starting can result from:

1 Faulty engine temperature sender - disconnect and see if there is any difference.

Check sensor resistance value - 2.5k when engine cold

2 Idle speed control faulty - check AAC valve operation / cleanliness

3 Check if the ECU is getting a "start" signal (probably difficult to check without CONSULT)

4 Cranking speed too low (unlikely with a new battery)

[GTS4-32]

Thanks, ill have to give them a shot and hope one of them will do the trick. Ill get back to you's on the result...

[MBS206]

When you car fires up, does it sound like it's popping and missing kind of thing?

When i first start my R33 GTS-t in the morning, (Or first time that day) I have to pump the throttle quite a few times, bring the revs up above 2500RPM, and then let it settle down and idle on its own.

If I try to turn the key, it cranks over perfect, won't fire, hit key again, it cranks, goes to fire, then dies, crank it again, and half the time it repeats and fires then dies, or it'll fire, sit there missing and farting at 800RPM, then "clears" and brings the revs right up to 1400RPM. And takes about 30-60 seconds, then idles down to 1100RPM, then takes about another 3-4 minutes to drop its idle to 750RPM where it's set too...

I might check my engine temp sensor once the car cools down.

[J_Red33]

When you car fires up, does it sound like it's popping and missing kind of thing?

When i first start my R33 GTS-t in the morning, (Or first time that day) I have to pump the throttle quite a few times, bring the revs up above 2500RPM, and then let it settle down and idle on its own.

If I try to turn the key, it cranks over perfect, won't fire, hit key again, it cranks, goes to fire, then dies, crank it again, and half the time it repeats and fires then dies, or it'll fire, sit there missing and farting at 800RPM, then "clears" and brings the revs right up to 1400RPM. And takes about 30-60 seconds, then idles down to 1100RPM, then takes about another 3-4 minutes to drop its idle to 750RPM where it's set too...

I might check my engine temp sensor once the car cools down.

I had similar problems for a while & it turned out to be vacuum leaks on hoses going to the plenum, meaning the AFM wasn't reading sufficient air flow. So you had to prod the throttle to get the air flowing through the intake instead of where the leaks were.

I had an air leak on the hose at the back going to the boost gauge sensor (very common on R33 GTS-T's), but the main leak was due to the dodgy hose setup going to the charcoal canister, which was fitted when the car was complied. Bought & stuck an original one on with all the right sized hosing & it was all good .

Try pinching all your vacuum hoses with your fingers while the engine is running & also check for cracks at either end of the hoses & listen for air leaks. If the Idle drops slightly when pinching a hose (and possibly smoothed out too) you've found your problem.

Edited November 1, 2006 by JazzaR33

[GTS4-32]

Yea, when i fire it up i have to rev it to about 2,500rpm and lay it down slow, then it sets itself up, idles at about 1,200rpm for a lil while like u said, then after a couple mins drops to its normal revs at about 800-900rpm. But its the starup that annoys me, like i sed i have to pump the gas to start it when cold. Otherwise it wont turn over.

I know it may sound stupid to you guys but where would i find the engine temp sensor on my car? I wouldnt mind cheking it out aswell.

[gtrchick]

Have you checked your coils.... is it like starting up a carby car at cold start?

[GTS4-32]

Nah its not that bad. The coils are fine.

[GTS4-32]

With the engine temp sensor, how do u check if thats the problem? Is it ok to disconnect the sensor and start it? How do i know if its faulty?