winner155

Went out this morning and tired to start my 94 LS 400. It would turn over normally but will not start. For the last week I have noticed that it took longer to start than normally, Usually it starts within a second of turning the key but yesterday it took three tries of about 4 seconds to get it to start. Does anyone have any idea what might be the problem and how to fix it? the car has 287m miles on it. I have to get this car running as I am down two cars and will have to rent a car if I cannot get this fixed right away.

Sneaky82

cap and rotor? when was the last time you did a tune up?

GS4_Fiend

iTrader: (22)

sounds like fuel delivery problem to me. get your fuel pressure checked out to see if it's within specs.

steve2006

Also check the crank position sensor and it's wiring, they can go faulty when cold if the ECU doesn't get the correct signal from this there will be no spark produced and the engine will not start, it is located low down at the front of the engine near the crankshaft pulley.

Yotarip

A bad driver's side distributor cap caused my no start problem. I noticed an unusually long turnover to start for a few days, then no start. Found two hairline cracks in the cap. Replaced it and problem gone.

billydpowe

iTrader: (1)

do a search, there are several reasons for this.

timmy0tool

iTrader: (7)

there you go. it's either this or your fuel pump.

winner155

Gee, thanks for the ideas guys. I know how to check a cap and rotor but can anyone tell me how to actually check or where I can find inof on how to check the fuel pressure and the crank position sensor and what tools would be needed? I really want to try this myself and not have to pay for a $200 tow. I ended up having to rent a car and I would really like to retrun it as soon as possible.. Again thanks for all the help

winner155

ALso, I did di a search on this and got everything from bad fule pump to a bad ECU and a few other things that might casue this problem. Does anyone have a suggestion on the order of how I should check these things, what is most likely and so on

Again, you guys have always been helpful and I am very thankful

winner155

To answer one question posed I tuned it up when I replaced the cam belt about a year ago.

Yotarip

The caps on the car were cheap autozone caps that failed a little over a year after installed. I chose higher end caps from napa this time.

I also bought a fuel pressure test kit from ACTRON and five adapters for each of my toyotas. The adapters can be installed permanently so that future fuel checks are a breeze. You replace one of the banjo bolts in the fuel rail with the adapter. Mid 90's GM cars have this style fitting on their fuel rails and I found that some in the junkyard still have the twist on cap that keeps crap out of the valve when not in use. I grabbed some of those caps also.



I have yet to find fuel pressure to be an issue with any of my toyotas/lexus.

fixmiester

Start with the basics: fuel or spark? Get a can of starting fluid (ether) and take the air supply hose off the front of the intake manifold. Open the throttle butterfly a little and spray the ether into the manifold for two seconds. Quickly try to start the engine with partial throttle applied. If it trys to run, even for a few seconds, then you have a fuel supply problem. If it doesn't try to sputter or run at all, then you likely have a spark problem.
If it points to a fuel problem, remove one of the caps (looks like a tire stem cap) on the fuel rails, and depress the valve stem briefly while someone turns the ignition key on, and off several times. If gas spurts out with reasonable pressure (don't get carried away with this, it's just a quick test to see if you have reasonable fuel pressure) then the problem is probably in the fuel injector control, i.e. ECU. But now troubleshooting can get more complicated, and and accurate fuel pressure measurement is called for, before diving in to the ECU, which does control the fuel pump, as well as injector pulsing. If no fuel spurts out during the ignition on test, then you have a clogged filter or defective fuel pump, or bad ECU.
On the other hand, If it points to a spark problem, then the ECU is also the primary suspect, but you can first try to measure the coil primary voltage, to see if they are at least being pulsed. This is where the Crank Angle Sensor and the ECU play together to create the spark timing. Try these tests first, and let us know which path is the culprit.

Steve

GS4_Fiend

iTrader: (22)

Yea that's true start with the basic first. What's the easiest to do. Like he said, get a can of starting fluid, open the vacuum line from the intake manifold (such as brake booster line the big one) and a person spray and another person start. If it's start then obvious it's a fuel related. If you got no spark and fuel at the same time then it would be the CKP sensor.

BobN54

If it does not sputter or fire at all, it is probably not a fuel issue. Look to ignition first.

winner155

Thanks, guys, I will check starring problem first. Being a novice, if I check the fuel rail, where exactly is that? I don't want to disconnect something I shouldn't. Also, is the vacuum hose to the brake easy to identify, I ssume it is the big black hose going from the brake booster into the enogine. I have to run back and forth between my garage and the house to look at this stuff and my memory isn't what it used to be,
Also, I got new distributor caps and rotor but I will be darned if I can find them on the engine, are they right in the front top of the engine on either side covered with plastic covers? How do the covers come off? oh how I long for my 69 Chevy with a 307- i could do everything on that.
Thanks

Steve