Starter or Battery or Goofy Electrical?

jeep
starters

#1

I have a 1991 Jeep Cherokee Laredo, that has just over 179,000 miles on it. Over the last year, engine start has been very strange; sluggish, sometimes requiring a couple of starts. I thought it was the battery, so my very reliable and ethical mechanics replaced it in late Spring; the battery was old. However, this did not solve the problem. This sputtering start would be caused by any of the following: cold weather, sitting for a couple of days, maybe the humidity, or sometimes I could have been driving around, park for 5 minutes, get back in, and get the sluggish, scary, is-it-going-to-start thing. The car is now back at the mechanics, and as Murphy’s law would have it, they cannot get the car to do what has been bothering me for months. This problem is sporadic and unpredictable. My fiance and I are getting ready to take this car from Brooklyn to Madison, WI, and I don’t want to be stuck in a cold climate with a failing starter. My mechanics are reluctant to replace the starter for $250 because their diagnostics don’t reveal a problem with it. While I respect this, I am frustrated that we can’t find the source of the start problems.



I know this is a long post, but does anyone have ideas about what could be causing these starter problems? Can the electrical be messed up? Is the starter draining life from the battery? Meanwhile, the car is still at the mechanics, because they want to have the car when it does this “thing”, and so far, the car won’t cooperate!


#2

Are you saying it turns over slowly or not at all, or is it turning over ok but not catching and running correctly?


#3

It turns over very slowly, sometimes threatens to stop completely. The last time it stopped completely was just before I replaced the battery.


#4

The first thing I would do is run a starter load test on the starter.
A load test is measuring the amount of current (amps) the starter requires, both on the initial engagement and during steady cranking.

This amount varies by temp, oil viscosity, engine wear, etc., but normally you could see around 300 amps or better at the initial surge and about 125, maybe 150 during steady cranking. 200 amps or thereabouts during steady cranking means the starter is dragging.
The ignition has to be disabled to keep the vehicle from starting to do the latter part of this.

I have no idea if this is your mechanic’s idea of diagnostics or not, but it’s the proper way of finding out what’s going on inside the starter motor.


#5

To be honest, I don’t know exactly what kind of diagnostic they are performing. I keep getting the report from them that it is working fine; since I’m not a mechanic, I don’t know what that means. I can give them a call and ask if they are doing this load test. Thanks!


#6

Beyond what you’ve already been told here, the only thing otherwise that I can think of is to remove, clean and reattach the electrical connections from the battery to the starter, at the starter. Also, make certain the ground cable connections are clean and tight from the engine to the body. It could be bad connections, but it’s more likely the starter.


#7

Thanks. I mentioned the connections and the ground cables, and the report is that those are all tight and clean. As yet they have not done a load test, the rationale being they haven’t noticed a start problem. But they have promised to do one for me ASAP.


#8

Okay, so they have done a load test and the car starts up at 200 amps, which I’m told is good; basically, the fewer amps it draws on start-up the better. Is this your understanding? Everything else checks out, and yet I know that as soon as I get my car home, I’m going to be parked somewhere and the car will have a sluggish start. I’m very frustrated at this point. Any other suggestions would be greatly appreciated!


#9

Have they checked the alternator output. If you make a short trip with the ac and fan on high, you may be draining the battery and the alternator may not be putting out enough current to keep up and recharge the battery. It may be putting out enough to keep up on a longer trip when you turn the fan down to a lower speed.


#10

I think I may have a serious disagreement with how they’re doing this.
It sounds like they’re watching a meter blip 200 amps momentarily before the engine starts up. If they’re doing it this way, they’re doing it the wrong way.
If the engine was disabled where it would NOT start then the current draw may jump to 3 or 400 amps.
Once the engine starts the load on the starter is instantaneously eased and a true indication is not given.

The engine MUST be disabled to perform this test by either pulling a coil wire loose, removing an ignition fuse, fuel pump relay, etc.
The meter should be watched carefully for the initial surge and what the current reading is during at least 5 seconds of continuous cranking.

The 200 amps sounds too low for an intial surge (their methods at work maybe?) and 200 amps is too high for continuous cranking (bad starter).

Maybe they have their way of doing things and if they are performing the test like this, then I have to strongly disagree with it.
It’s preferable the test be done when the engine is warmed up also as cold engine oil can affect the amperage readings.


#11

The battery weakens and the engine cranks slowly. See if the insulation on the negative cable is cracked. Look for the engine to firewall ground wire and clean the firewall end. Take it off and scrape it or use a wire brush, clean the firewall where it attaches. See if the starter goes fast with a jump. If the starter is loud or makes a scraping noise, change it. The other people’s advice still applies, of course.


#12

If you have a good battery, clean cable connections and a starter problem, then why not replace the well used starter? You got your money’s worth from the original. What else could the problem be? It certainly sounds like a failing starter. Replace the starter and if you still have the problem, then put the old one back. At this point you must do something rather than nothing or else get another mechanic to look at it.


#13

It’s about 90% chance, in my opinion, that you have a bad starter. I would tell the mechanics to replace it, and promise not to blame them if it turns out to be something else, which would be very strange.


#14

I had a similar problem that turned out to be the starter motor. I had the starter replaced by Western Auto just after it was taken over by Sears. When the engine was hot, the starter would barely, if at all, turn the engine. I took the car back to Western Auto and they claimed that they could not duplicate the problem. I took the car to an independent shop under the conditions when this problem occured–hot weather and the car had been running for a while. The mechanic put an ammeter on the starter circuit and noted the current draw. He then disabled the ignition to be certain that it wasn’t timing that was advanced too far and repeated the test. He wrote down the current draw on an order form for his shop for me to take to Western Auto. He didn’t charge me for this diagnosis,even though I had never been a customer. Two positive things happened: 1) Western Auto replaced the starter without any questions and 2)this independent shop gained a customer. This was 14 years ago and I still go to this shop.


#15

Thanks everyone for the input! On Monday, I told them to just replace the starter, because I suspect they were not disabling the engine during the load test. I agree that I’ll just take my chances, and not blame them if it turns out not to be the problem. As far as I tell though, what else could it be?