Chevy starter issues

[Greg Reimer 7376]

Got a 91 Chevy pickup,350 TBI motor, bunch of miles, still runs pretty great for 290,000 or so miles. Seems that this truck always has had starter issues, replacing it makes the problem go away for a while, has the usual GM Chevy hi torque starter, the problem is that it starts fine first thing in the day, but drive it a distance or on the road, and it has a chronic hot no start condition.Turn the key to Start, not a sound. The gauges move, there is current where needed, but it won't even activate the starter when hot. Let it set a few hours and it's fine until it gets hot again. Starter won't make a sound or do anything when hot. I've put four or five starters in it but I've also had the truck almost 22 years. Other GM cars seem to do the same thing. Any ideas regarding a chronic hot engine no/start?

[FED 387]

Sounds like you might need to protect the starter with some type of "heat shield" to prevent heat soak------GM made them not sure for which vehicles newer vehicles probably have them--- ALSO as old as that truck is(30 years) and the hi miles (300,000) I would replace both the positive and negative battery cables also check the chassis ground for the negative (is it nice and shiny or is it real rusty?) install an additional ground strap from the head to the chassis ---Actually First thing would be to check your voltage at both ends of the positive cable (starter end and battery end) should be like 14 volts if there is any difference you know its in the cable might be terminals or the cable itself ---it takes a lot of voltage to run a cold starter but when it gets hot it needs even more or all it can get--- just a few suggestions---FED 387

[BillK]

Going to say the same thing as fed. My Wife's Riviera was doing the same thing and it turned out to be the positive battery cable where it connects to the battery. Check and clean all of your cables and especially the grounds. If I remember correctly those trucks had a ground going to the back of one of the cylinder heads that would get corroded. Make sure and take that one off and clean it real good.

[Mark Ugrich]

Ignition switch?

[Jeff Niceswanger]

It might take a few minutes to hook up, but I would make up a switch, or use your bump starter and hook one of the leads to the main side of the starter solenoid itself and the other to the start position (S terminal) of that same starter solenoid. When your issues flair up, grab that bump starter and see it everything works as normal. Your effectively eliminating the electrical system out of the equation. If that works, wire up a 'hot start' old style Ford solenoid remotely and hook it up to your existing starter. The original start wire will trigger your new solenoid. Run 12 gauge wire to (From the Positive Battery) and from the new solenoid down to your old starter solenoid S terminal.. We did tons of these when I worked as a fleet mechanic @ Ralston Purina.. Old systems degrade and it's just as easy to wire up this set up than go through all of agony..

EDIT. Here is a kit
https://www.holley.com/products/elec...s/parts/51340G

https://documents.holley.com/199r11281.pdf

Continuous Duty one ..
https://pitstopusa.com/i-22954444-ta...-and-ford.html

[Greg Reimer 7376]

Thank you all for your input. I've had this truck since December of 1999. It's the best toy I ever had, save for one or two race cars that seem to be easy to go rounds with.I equipped it with dual batteries which are the 24 S category, and the original Group 74 cables have been replaced a few times. It seems that there is some kind of resistance connection problem between the front wiring harness and the fuse box, dash,and the ignition switch. I replaced the ignition switch recently, the truck has factory gauges, the alternator reads just under 14volts with the engine running, testing both batteries with a DVOM reads about 13.6 volts, I feel there is some kind of impedance problem between the under hood harness and the dash harness, maybe a firewall plug issue or something like that. I have noticed that driving at night, the headlights don't look real bright, there has to be a high resistance condition somewhere. I will check the grounds at the rear of the one head, as well as any other things like that. This truck has never been apart. The intake has never been off, neither has either valve cover. It's the best toy I ever had, with the possible exception of my Chevelles and my 409 I had years ago. Sometimes when something never gives you any problems, it's a bit bigger of a job to troubleshoot it when it does.

[FED 387]

If Im not mistaken doesn't the main vehicle electrical power come from the positive post on the starter?? If so might check the cable coming off that post and the terminal end too----as old as that truck is over the years between vibration heat and the weather that lug may have deteriorated---also are the replacement starters GM look a likes (offshore knockoffs) or are they either new or rebuilt BY GM/AC- DELCO starters?some of that crap does not have a very long life to it---also check the body grounds for good contact with the frame--FED 387

[Greg Reimer 7376]

Thank you all for your contributions. All of them certainly do apply to GM Hi Torque starters. All your suggestions were good ones. Heat certainly applies to starters, relays, and all other matter of electrical things. The truck has new cables. I converted it over to the 24 S style battery about 15 or so years ago.I also fabbed up and installed an auxiliary battery tray for it and installed it on the driver's side of the engine compartment across from the OEM tray. The auxiliary battery has a long cable that connects it direct to the positive post of the battery in the factory tray. The auxiliary battery has a shorter cable directly connecting the ground post on the aux battery to the alternator bracket. That's directly bolted to the driver's side cylinder head. The ground from the main battery is bolted directly in the OEM configuration to the AC compressor stand. The main battery cable from the OEM battery goes down to the 3/8"stud on the starter. The starter activation wire came off the solenoid, runs through a tubular heat shield behind the engine on the right side away from the right exhaust manifold. I had added another wire to that post, ran it through the heat shield and up to the firewall near the distributor, pulled it through a grommet, and ran it under the dash to an auxiliary push button switch to assist with hot starts. None of the original side post battery hardware or cables has been there for some time.As I had the starter out a time or two recently to search for this hot start issue, I noticed that the wiring through the tubular heat shield looked pretty bad from an insulation standpoint.I went down yesterday and bought a 14 foot roll of 10 gauge insulated copper wire and some eyelets. I began by soldering and crimping the eyelets to the ends of the wire, fed both starter engagement wires through the heat shield with the new battery cable that I bought, finish tightened my starter and all the terminals, then located the 10 gauge purple wire from the ignition switch, cut and spliced it all very securely, then hooked it all up. I have an auxiliary push button switch under the dash, that was part of my hot start problem elimination, but the button had gotten so hot inside it had come apart internally. That's next to replace. Right now, the truck starts so well its hard to believe its the same truck. All I gotta do now is replace the auxiliary push button. Another thing I noticed, the two battery ground cables attach to the engine. It seems to me that a better path to ground could be achieved by getting a battery cable with two eyelet connections on it, like a Ford starter cable, then attaching one end of that to a good dedicated ground on the engine and the other end directly to the frame, plus at least a 10 gauge wire auxiliary ground to the body from the frame. That is to prevent any voltage drops from occurring anywhere in the system. Right now, the truck starts and works better than it has since I bought it. Seems like getting back to solid basics here cleared up a lot of things. Thanks for the tech advice!

[Greg Reimer 7376]

Final note-- I checked at the lower corner of the right head, there is a flat woven ground strap that runs from the head surface directly to the frame. The other leg of this flat woven strap attaches to a dedicated body ground at the lower corner of the heater/AC box. This thing is definitely grounded! I never really cared for the side post battery when it came out about 1970 or so. The positive post seems to leak, corroding the connector and the terminal inside the battery. Often they break off all by themselves. Another thing to get rid of,I suppose.