car trouble

[rh71]

Hopefully someone with car knowledge can help me out...

Starting the car, it would SOMETIMES choke for a quick half second and then nothing (silence). But the 2nd try ALWAYS starts the car. This went on for months.

Tonight was a different story. It choked for a quick half-second about 3 consecutive tries. 4th try it started half way, just when it was about to start (turn over), it was silent again. A few more tries and it finally started.

Is this a sparkplug problem? Battery? What can it be ? It's a 95 vehicle and the sparkplugs have already been changed once or twice in the past. Maybe it's due for another? Would like your ideas. Thx.

Also, if you guys know of any car trouble discussion boards (awesome concept, isn't it?) ... please let me know!

[caddmannq]

Are you saying that it only cranks for a second, and then stops? Then this sounds like dirty/loose battery cables. These often lead to a fried battery/starter. Remove, clean & tighten both ends of both cables & see what happens. If this doesn't fix it, jump it from another car & see if the situation improves. If it does, then it's probable that the battery's shot. If it doesn't, start looking at the starter, or starter soleniod (if so equipped.) Also, once you clean the terminals, turn the key to on, but do not start the car. Turn the headlights on high. Step on the brake & blow the horn at the same time. The horn should be loud, and the lights shouldn't dim more than a tiny bit. If they do, then the battery or cables are suspect.

What kind of car is it? Do you have a portable voltmeter or multimeter to test things?

[rh71]

Yup, most often a half-second crank, then silence. 2nd try always successful. Tonight, that wasn't the case.

Got a multimeter, but I believe the car (95 Isuzu Rodeo) is due for a tune-up anyway... only had 1 in its life after 69k. So you don't suspect a sparkplug issue? Would a tune-up take care of a starter solenoid problem since I need a tune-up anyway?

Good tips, by the way... thnx.

[Richard Cranium]

I can't comment on the exact vehicle but I'll give some general suggestions.

More questions, does the vehicle run "perfectly" when Hot ?

If it looses power on very slight hills, and stumbles on start you could have a bad EGR valve. The spring inside gets weak and allows the valve to open early and open during start.

You can unplug the EGR valve's vacuum hose to test.

other things

A leak in the intake manifold or any vacuum lines or under the throttle body can cause similar running.

If you have a propane torch you can check for intake/vacuum leaks yourself.

DO NOT LIGHT THE TORCH, simply open the valve slightly and allow the propane to float around the suspect areas while the engine idles.

Only do this for a minute or so that you don't allow the propane to build up and possibly ignite on a leaking spark plug wire.. Also only do this procedure outside.

A flammable penetrating oil will work also, I don't like to use it cause it can make intake leaks worse by washing out carbon buildup making repair time more immediate.

[rh71]

Now that you mention it, the car has felt weak at times. It is a gas guzzling SUV so I don't like to step on the accelerator too hard on hills and starts from lights. But I see other cars going up inclines much faster than me and it's not like I'm light on the accelerator either.

But will all this be fixed with a tune-up?

[caddmannq]

Maybe. Maybe not.

A tuneup nowadays consists of changing plugs & cleaning fuel injectors & sometimes an oxygen sensor. A good mechanic will clean the battery terminals too, and may test the battery. But you better mention this stuff up front, ou you're likely to be going back.

If this car wont crank for 10 seconds steady and fast (even without starting) you've got a battery/cable/solenoid/starter circuit problem. The only other possibility is the actual ignition switch/wiring is defective.

Set the meter on 20vdc & test the battery (car not running.) It should read about 12.5 volts. Have someone start the car while you watch the meter. It should drop to about 10.5 for a second while the starter cranks, and then shoot up to 14.5 when it does start. If it drops below 10 while cranking, the battery/cables/starter/solenoid circuit is suspect. If it does not drop down, and yet the engine fails to crank, look at the ignition switch/wiring.
I've seen several imports with A/C that have burned up the ignition switches.

[rh71]

Alright, the car had been sitting there 1.5 days now without a start attempt. This morning I try to start it up to take it to the shop and it wouldn't start at all.

Every turn of the key results in a very short click sound (not even like an engine crank sound). It's the same half second click I've been describing from the beginning... the same click sound that happens on almost every first try to start the car... (you may recall most 2nd tries are successful)... This morning, it won't start at all - after about 10 tries. Under the hood, the contacts to the battery LOOK fine (not rusted, etc)... dad tested voltage to be OK (little above 12v I believe).

So is there something else I should look for so I can at least get it to the shop without having to tow it in ? I know I'm describing mostly the same things to you, but this click sound, with seemingly no engine turnover, should indicate something more specific to you guys... ? Thanx again for any pointers.

[Knothead]

Yeah, I think you'll have to jump it, then drive it to the shop...Cadd's advice sounds right on the money, i.e., starter/solenoid or battery/voltage regulator/alternator. Prolly the latter.

That short 'clicking' sound is what you hear when the battery ain't got the juice to really roll it over. Good luck!

[caddmannq]

Did you do the lights/horn/brake light test?

It could be a burned solenoid.

Also, a battery can test 12 volts with no load, but not be able to deliver any amps at that voltage because of an internal crack or meltdown of the conductors.

You might have a constant drain on the battery, with the key off, too. (Actually all cars do, but it's very slight. A healthy battery should take months to drain down in a good system.)

Alternators with bad diodes can do this, plus they will only charge weakly. Also any short, a computer malfunction, interior light that does not go off (sometimes under the hood or trunk where you don't notice it) even a defective radio, can drain the battery while you sleep.

Problems in the starting/charging system also "feed" on each other. For instance: A poor cable connection will make the car hard to start. This drains the battery a bit too much. Plus it makes the alternator work harder to replace the extra drain, plus fight the resistance of the bad connection. This puts a strain on the alternator, leading to regulator & diode burnout. This further reduces charging of the battery, which increases amp draw at the next start. The high amp draw further worstens the connection, plus burns contacts in the solenoid, and brushes + windings in the starter. This causes even more amp draw, harder starting, and melts down the internal connections between cells in the battery. It doesn't have to happen in exactly that order: but it's all related as a system.

This cycle can go around and around until one componant of the system fails, and the car does not start at all.

But replacing the failed componant usually does not completely fix the problem, and another failure can occur. You must determine the health of the entire system, and find the root cause of the problems.

90% of the time, these things all point back to a loose or corroded cable as the instigator: but assume nothing. Check everything.

If your mechanic replaces the battery (or starter, or whatever), ask him if he cleaned & tightened ALL the cables (on BOTH ends!), did an alternator output test, and a starter draw test, and a battery current leakage test.

Without those, he's just guessing.

Indeed. Same thing happened on my 81 Corolla (I miss that car). The alternator decided to half die and took the start solenoid with it. -click- -click- -click- -click- -click, vroom-

Well, with that car it wasn't really a vroom, more of a... Well, I really can't even recreate that sound.

-Whir