Scott R

Hello all, was hoping for some help in diagnosing this...

A couple of weeks ago I got in my SC430 in the morning and went to start the engine. It didn't catch in the normal amount of time that my brain was expecting, so I had already let the key go and it didn't start. Tried once more and this time it started fine. I thought it odd but figured it might be user error.

The next couple of days I noticed that it felt like I needed to hold the key a tad longer to get it to catch, but still wasn't sure if I was maybe imagining it. I took it to a NAPA auto parts store where they checked the NAPA battery I had (replaced about 1-2 years ago - I forget now) and they said the battery checked out fine. Although there were no obvious signs of corrosion, the guy recommended that I disconnect the terminals and use a steel brush clean everything up. Another guy behind the counter recommended some spray gunk that he had used, so I picked that up as well as a steel brush gadget.

The next morning the car wouldn't catch. Note that when turning the key it sounds like it's *going* to catch (no clicking or whirring or anything like that), but it just didn't. I held the key in place for maybe 4 secs before letting it go. I was in a bit of a hurry so I decided to try the spray-on stuff. I let it sit for about 5-10 mins and then tried again. This time it started fine but I wasn't sure if the spray had done the trick or if I had just "primed it" enough from my first attempt that it would have likely started fine the 2nd time, even if I hadn't used the spray.

Also worth noting that I typically have trouble starting it the first time I use the car that day, and if I'm out running errands, it usually starts fine every time after that.

We had to leave for a week's vacation the next day, so I put my car into my garage backwards, expecting that I might need easy access to the engine compartment when we got back. Sure enough, when we got home a week later it wouldn't start. This time I disconnected the battery terminals (a pain since none of my wrenches wanted to squeeze in there easily) and gave everything a good scrubbing with the steel brush I got. I still hadn't seen any noticeable corrosion though.

After that it started fine and even started fine the next couple of days. Yea! I thought I had fixed it.

Then last night we go out to dinner and after dinner it didn't want to catch. This was especially odd since it wasn't the first time I had driven it that day. Once again, though, on a subsequent attempt, I was able to get it to catch.

This morning I brought it to a local repair shop and explained the situation (they were booked up and couldn't look at it today). The guy seemed to think that it was unlikely that it was the battery, starter, or oxygen sensors, but was likely something to do with the fuel pump (or something related to that).

Does his diagnosis make sense? If so, any thoughts as to what I could be looking at money-wise to fix? Any particular reason why I should bring it to a Lexus dealer to fix, versus this local shop? Since it's so far out of warranty, I try to avoid the Lexus dealership and save money where I can.

bb430

iTrader: (1)

How many miles is on the car? What maintenance have you had done? Maybe clean the mass flow sensor and change the PCV valve. I would think it's the fuel pump as well, after it gets warm it works fine.

Bgw70

Do you mean the engine does turn over, but the engine will not start?

If yes, someone else had this problem recently...

mrblister

Your info is confusing does the engine crank and not start .Does the engine crank slowly ? The sc430 are known to use current when just sitting. Most people will wind up using a battery tender to keep the battery up.

If your turning the key and holding it in the start position and nothing happens and then restarting it does start sounds like a bad ignition switch.

FLYCT

Not sure of your description of the symptoms. What exactly does "catch" mean?

Does the starter motor engage, engine turns over but will not run when key is released? If so then it's either a fuel or ignition system problem

OR:

When trying to start is there no sign that the starter motor is turning over the engine!? If so the it's an electrical problem. Could be either a poor connection at battery, connection at starter motor, connection at starter Solinoid or a bad starter motor, bad solinoid or ignition switch etc.

ShawnOk

iTrader: (1)

I have this same exact problem. Some mornings I have to hold the key just a millisecond or two longer (or even pedal the gas a little) and then after first start I do not have a problem for the rest of the day. Exact same scenario as explained above. I've checked battery and alternator in the past. Both work fine and passed all tests. I'm suspecting fuel pump after lots of discussion and troubleshooting. I was told this can be diagnosed by checking pressure in the fuel line during a cold start but haven't taken it to my mechanic as it seems my problem has improved recently.

Bgw70

Is the engine turning over but not starting?

Scott R

Sorry guys if I've done a poor job of explaining things or have used incorrect terminology. I have next to no experience repairing anything on my car, so I may be using incorrect terminology. I thought I avoided confusion by being extra descriptive in my post, but I guess not.

After reading some of the replies, I think I should be saying that the engine turns over (cranks) but (sometimes) does not start once the key is released, or that it requires that I hold the key a second or so longer than I used to have to in order to get it to start. I was using the term "catch" to mean "start/run once I let go of the key."

Again, when I hold the key in the start position, I hear the engine "turning over" (if I'm using that term correctly), and I *DO NOT* hear clicking or whirring. So, the engine sounds normal and it sounds like it's going to start, but when I release the key (after the normal amount of time that I've been accustomed to needing to hold it in the start position) it *sometimes* doesn't start. Usually, this only occurs the first time I've attempted to start it that particular day, but I did have one case where I had used the car, driven to a restaurant, and when I left the restaurant it had trouble starting. One extra data point on that one exception: It had rained heavily for a short period of time while it was outside the restaurant.

So based on the mechanic I talked to and at least one reply in this thread, it sounds like it probably is related to the fuel pump. If so, how much money am I likely looking at to repair and is there any reason why I should bring it to a Lexus dealer for this, or is it fine to bring it to a reputable local mechanic?

Helogadget

My suggestion would be to take it to the dealership and describe to them the problem. Let them troubleshoot the car instead of an independent mechanic. They have the resources and experience (for Lexus cars) that an indy mechanic may not possess.

Just my 2 cents.

LexBrett

If your car sometimes takes longer to start, and it's high mileage without proper maintenance, that's normal. Cleaning the fuel injectors with Lucas, cleaning throttle body and MAF, replacing PCV valve, changing plugs- all will do wonders. Also the batteries on our cars suffer from parasitic drain so they did really quickly. I run a voltmeter on the battery plug top off with battery tender from time to time. Whatever you do don't let a mechanic do this stuff will charge you thousands and lie. You can do it on your own we can help you and provide you DIYs!!

Bgw70

I too want to second LexBrett if your car is over 100k miles. How many miles do you have?

You said you do not work on cars, that is fine, but it is a machine and you must perform more maintenance than oil and air filters.

LexBrett gave you a list, get it done if it has not been done.

BTW, have you had the timing belt and water pump changed?

Again, all of this depends on how many miles and the age of your car.

kjcole

LexBrett beat me to it...................Start simple. It is either fuel/air, or electrical, which means many, many possibilities. If you were more experienced in auto diagnostics I'd tell you to (depending on mileage and maintenance history), start with the routine 'tune-up' items (air filter, plugs, plug wires, PVC valve, MAS sensor), and then work your way to things like fuel pressure, cold start sensors, etc). But since by your own admission you aren't very experienced in these areas, I'd take it in for some diagnostics.

FLYCT

What you now described could very likely be caused by a fuel pump.

With injected engines the injection system is under pressure supplied by the fuel pump. if the pump check valve is leaking internally then after sitting over night pressure is lost. It then will take a few seconds for pressure to rebuild first start after sitting.

The pump also could be slow to start up after sitting.

This is easily diagnosed by the mechanic putting a pressure gauge in the fuel injector system and monitoring it.

I had a 300zx that had this exact same problem and that's how it was finally diagnosed.

Bgw70

And another way to check this would be to,
-turn the key on, engine off. For three seconds
-turn key off.
-turn key on, engine off. For three seconds
-turn key to start.

Did the engine start?
Please report!

If you do this, the fuel pressure will build back up allowing the engine to start on your first try.
It will also help you determine that you indeed have a fuel pump problem.
If this works for you, take the car to a mechanic and ask him to perform the checks FLYCT suggested!

LexBrett

Also, are you getting a Check Engine Light? If so, you can go to Advance Auto or a similar store and get that checked out for free. That should narrow the possibilities. Then look online for the interpretation of the code and please tell use what you find!