Hey guys...when I start my car it takes a lot longer now than it used to for the engine to crank. A good bit longer than normal. Could this be the spark plugs? Thanks, Adam

 

696,

Need clarification......the car cranks longer before it starts? how long does it crank? that sounds like ecu control. Does it run smooth after it starts? any roughness or stumble? that would sound like plugs.

 

sounds smooth once it starts. Takes a few extra seconds than normal to crank.

 

This happened to me a little while ago. I didn't think it was my battery, but it was. Now my car starts up quick and incredibly smooth.

 

I have a problem where I start the engine and it stumbles for a moment when it's cold, then it gets going. Adam did that programmer Chris had do an idle/starting map for the ECU?

 

Does it hard to start once the engine is warm up? Meaning after driving the car for a while the engine is warm can you stop and start the engine after it shut off for a while?

The 93 SC400 has a cold start valve so I think my green SC400 cold start valve need to be clean of replace. I don't know if 95 SC400 has cold start valve or not.

 

madmax: I dunno

 

I keep forgetting about the cold start valve, I'm glad you mentioned it. I think I'm going to break down here and buy one JUST TO SEE if it fixes the problem. Our problems might be similar, mine might be plugged up, Adam's might be straight broken.

 

MadMaxSC400 & abutler696. You not only need to pay attention to 'what' the symptoms are but equally as important 'when' they happen, just as VQT was suggesting. If the problem is more pronounced when the engine is cold then I would suggest checking all cold start related components & of course checking your plugs(proper gap/heat range/application). Possible to have leaky injectors. If your problem occurs when the engine is warm, hot-restart, once again, check the aforementioned & possibly fuel pressure. Check for fuel pressure bleed down. You should have at least 30psi over a one hour period. Also check for fuel pressure during cranking. Hot engines require higher fuel pressures during restart in order to combat fuel percolation, when fuel boils due to underhood temperatures & causes air pockets in your fuel rail. Higher pressures raise the boiling point af any liquid. This is all assuming that your engine cranks normally, hot or cold, but has difficulty actually starting/running. I hope this allows you to concentrate your efforts on finding the root cause of your complaint & all is intended to do the proper repair the first time without unnecassary expense. Hopefully it's just plugs. Good luck!

 

It could be anything. I don't want to throw out suggestions unless, there is more info. on what the symtoms are.

 

Mine did the same, I replaced my battery with a new one and the engine cranks right up and smooth.

 

It's always cold starts. When the motor is warm, it's fine. I have thought that the battery might be a little weak, it's been known to let my sub crackle when the engine's been off even for a short period of time.

 

MadMaxSC400, if you suspect a weak battery, I suggest to get a local shop, with proper equipment of course, to check that your battery has sufficient reserve power to start-up your vehicle when cold. Have them check that your battery's OCV (open circuit voltage) is at least 12.6volts & have them load test your battery. All this should not commence until you are positively sure that the battery in your vehicle is the one recommended for your application. You see, cold engines require a few more cranking amps than a warm engine due to friction (cold engines are harder to turn over due to lack of oil lubrication in the engine at start-up). In addition, warm engines have a greater potential to start-up due to the retained heat & fuel mixture that encourage initial combustion. Don't forget to have this local shop check your starting & charging system integrity, i.e. - voltage drop tests, charging voltage, charging current under full electrical load, alternator belt condition & tension, etc. As a final note, hopefully your stereo & or any other creature comforts are turned off when you are trying to start your car, as sometimes this is all that is needed to cure a 'hard start' problem.......sometimes. Best of luck

 

lextec you talk JUST like my second auto shop teacher in high school, he worked part time as a mechanic at the local Porsche dealer. I do have a load tester and a charger, and I will do the tests accordingly. From the experiences I've had so far I believe that the battery is not able to provide enough power to the motor for a couple of seconds. When the car's been left for a long time (number of days), the engine lurches and the lights dim on the valleys of those lurches unless I hold the throttle downa little to give it some gas. It's almost like the battery and the cold start valve are causing problems at once. Since the battery is old and could use replacing, I'll do that first.
Thanks!

 

MadMaxSC400, you are welcome. Hopefully we have shed some light on hard 'cold' starting problems & I hope that the battery is the fix for your complaint. Well, whatever the result is, please let us know what the outcome is. Looking forward to your next post.