still a weak crank on startup

P

pdxgeo

True Classic
Heres what its not...

Starter/solenoid - new
Battery - new
Ground straps (now 3 total)

What else could it be?

Starts up but initial crank sounds weak. Like a kow battery would sound...hmmm maybe the alternator isnt charging but the battery would eventually die no? That hasnt happened.
 
Tried jump starting it

If you are wondering about a weak battery.... have you tried jumping it from a running vehicle? The behavior of the crank up under those conditions should tell you something.
 
pdxgeo said:
Heres what its not...

Starter/solenoid - new
Battery - new
Ground straps (now 3 total)

What else could it be?

Starts up but initial crank sounds weak. Like a kow battery would sound...hmmm maybe the alternator isnt charging but the battery would eventually die no? That hasnt happened.
Click to expand...

How are the battery cables? I had a cable that looked good but was corroded up under the rubber insulation. Of course it was a cold windy night when it decided to give problems. Clean snug connections are a help. Also even thought it is a new battery charge it up and put a load test on it. There could be a chance one of the cells are bad. Most parts stores have a tester that you can use when you bring the battery in.
 
Strarter motor bushes are worn... starter motor brushes are worn/sticking...test the current draw with an inductive ammeter while cranking.

SteveC
 
hmmm

The starter is brand new (remanufacured marelli)

The issue was the same with the previous starter and and persisted for about a year or more then last weekend it wouldnt start. I hit the solenoid with a stick and it started. So i swapped in a new starter and a new battery just in case. I also added a new (third) ground strap and it still starts slowly. Battery cables and clean connections are making the most sense because they are the constants...i will investigate. Thank you all
 
What are the cranking voltages (at the battery) at the starter (might be easier to test at the Alt (see what the 12v drop's to when you are cranking) Test the larger wire at the Alt.
 
+1 on battery cables

Easy to check the battery cables and connections. Crank the starter and then feel the cables and connections. The bad one(s) will be noticeably warmer.
 
Check the ignition wire connectors on the steering column. Look for signs of heat/melted plastic. Also there is a large connector on the left side of the engine compartment with 10 gage brown wire. Look to see if it has heated up. These wires can get hot and melt the plastic causing corrosion and resistance. Experienced this on 128's.
 
+1 on this.

Also, there is a connector on the engine side of the firewall that has four fairly heavy brown wires. Check to make sure those connections are not corroded in any way, and that the connectors fit snugly.

This connector is up behind the brake booster.
 
roadster27 said:
Also, there is a connector on the engine side of the firewall that has four fairly heavy brown wires. Check to make sure those connections are not corroded in any way, and that the connectors fit snugly.

This connector is up behind the brake booster.
Click to expand...

"This connector is up behind the brake booster" That is the one the connectors I was talking about. It has been a few years since I owned a 128.
 
The ignition switch and that big junction/connector would have an effect on most of the vehicle electrics but I don't think they would slow the starter. The starter circuit gets power directly from the battery via the big battery cable. And ground via the major ground cables. I would investigate the ignition related stuff only if the solenoid wasn't getting enough juice to engage.

George, do you know the company that did the remanufacturing of the starter? Are they reputable? I have encountered some pretty shoddy work being sold as "rebuilt" over the years. If they stuffed new brushes in and gave it a coat of paint but the commutator is worn or the windings are bad, then that could explain things. It might be worth inspecting the electrical connections on the starter/solenoid to make sure stuff wasn't painted over and then assembled, causing electrical resistance.
 
Hi Court, I bought the starter from Mike M who got it from Obert many years ago. If I had to guess I'd say it's top notch but I still need to clean all contact points, terminals etc.

Thanks
 
128kid got it right and set me straight on the connector suggestion. The starter works off the POS cable from the battery. I wasn't thinking right as if I ever do. Any way we are back to square one. It is either bad connections between the battery and starter, a bad ground connection from batt to frame, a tight engine, timing too far advanced or you might have a starter that is binding or the starter it's self might be the problem. Have you bench tested the starter?
 
Internal resistance in the starter. The solenoid only affects engagement, it sounds like it's engaging fine but doesn't have the torque to turn the engine when it's hot. You need a new starter. Ill pm you about some good used ones.
 
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