I've been chasing an intermittent hot start issue literally for years. I may have posted about it here at some point in the past, but can't find that old post. In the meantime I do have more info that might help narrow things down.

When cold the car always starts. When hot the car will always start if not left sitting too long. For example, when refueling there is never an issue restarting. However, if left to heat soak for 15 minutes or so the car will sometimes not restart. The hotter the day the more likely that is. The dash lights come on, but the starter does not operate. No clicks. Nothing. After that the car will always restart if you sit around long enough. No more than an hour does the trick. The hotter the day the longer the wait.

The battery is new. The starter is new. The fuel pump relay is new. I'm out of ideas. Any thoughts?

Thanks,
Ted

Here's an update on what I know so far. The starter tested good. As a test the neutral safety switch is by-passed with a jumper in the connector. The connector is located on the right side of the center console. So far the problem has not happened again. I'll test things like this a bit more. If this proves to be the root cause, I'm not sure if I should even bother debugging further or just leave the whole neutral safety switch and wiring bypassed.

-Ted

My symptoms were similar, which are posted on the forum.

My best tools were a voltmeter and wiring diagrams, particularly the charging and starter circuit diagrams. In the end, I proved it was a bad starter solenoid, and replaced the starter. The small Blue/Yellow wire going to the starter solenoid was getting 12V+, but the solenoid was not engaging. When I hit the solenoid with a long stick, it engaged and started.

But along the way, I discovered low and intermittent voltages throughout. Cleaning the B+ Red wire terminals and all the grounds fixed that. Then it was just a matter of waiting for the no-start condition to repeat and having a voltmeter handy to see where you are not getting voltage. You'll need someone to turn the key while you test for voltages in the starter circuit.

The previous owner had replaced the 60A PAL ignition fuse with an inline fuse. The PAL slot was fried.

I don't recall from where I downloaded the wiring diagrams, but I have them in PDF. Just let me know and I'll send them to you.

Thanks.

Your post https://www.brickboard.com/RWD/volvo/1614163/220/240/260/280/crank_hot.html was a shining example of good troubleshooting and problem resolution. Well documented and thorough.
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Art Benstein near Baltimore

Those who jump off a Paris bridge are in Seine.

I once had similar symptoms on a '90 760 that just had the starter replaced a few months earlier in the winter. With the growing hot weather of early summer came more frequent "no-cranks/no-starts". Since the starter was replaced by a local shop, I wanted to be very sure it was the "new" starter before I went back to present my case. For some reason whatever testing I did brought my focus to the starter. What I do remember was setting up a routine of a test to model by experience. I drove the car around the town in a 20 minute loop to bring it up to temperature, parked the car in my driveway, attempted a start/crank 15 minutes later. I most often got what I expected, no-start/no-crank. When that happened, i directed a solid spray of water from a garden hose to the starter/solenoid. Every time the car would immediately start. That test and electrical checks convinced me the "new" starter was at fault. The shop agreed and replaced it for no charge. The water spray is a no-cost, no-tools, no- talent, no-time check. I had no-start/no-crank even with the car parked in the sun all day. Driving or parked in the sun was enough to raise temperature in the engine bay and cause no-start/no-crank. This symptom later occurred on a '92 245. Again, the test helped me zero in on the solenoid/starter.

For the fun of Volvos,
Mike
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'92 245DL, '90 760 GLT

Mike, I love the idea of water cooling to diagnose this. We almost always have a bottle of water stuffed in a map pocket...


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Art Benstein near Baltimore

The short fortune-teller who escaped from prison was a small medium at large.

Hi,

If you have an automatic, no power to the starter might be a symptom of a faulty neutral safety switch. If you haven't already, it might be worth a look.

Heat causes expansion and it's possible that at a certain temperature it's enough to upset it.

Peter

In my thinking, a no crank condition under excessive heat means high resistance somewhere.

In most cases it's a bad ground cable on the engine block to the battery or the ground wire off the solenoid on the starter.

The next thing that comes to mind is either, a bad ignition switch or wires to or from the solenoid.

Excessive Heat can cause wire windings, in either the solenoid or the starter motor, to pass less current or the wires to expand in length.
Starters on Chevy 454's have to have heat shields to protect them from their exhaust pipes.

If there is a poor connection joint, somewhere along any of the previously mentioned wiring, intermittent symptoms can occur.

I feel this should be very rare since you have replaced thes component but I would recheck all of them.

You might try troubleshooting the ground side of these with a digital voltmeter or a very low range (one volt or less) analog meter.
Clip the leads over or parallel to the ends of all cables and any ground wiring back to the battery.
Positive to positive side and negative to negative side each.

When cranking the engine or using a circuit, you want the voltage reading to continually read zero volts. .02 to .04 is a healthily ground. Anything higher is not good. .2 or more is terrible!

These low numbers may not seem like much but they represent a high resistance causing voltage drop or current being restricted from going where it should go.

A partial broken (lame) wire, loose connection or a corroded wire can be condemned as being all the same.

If you could go with it a fuel boiling problem why not try to carry a jar with water and a rag in it.
Use it to cool off the fuel rail and the FPR.

Hope this helps shed some light, to help focus the eyes, on the systems possible faults.


Phil

Thanks Phil. Yep it does sound like a wiring issue. It could very well be at that horrid fuse block Randy reminded me about. So I think i go over that closely, get things cleaned up and/or replaced and see how it goes from there. There is definitely an issue there as the fuse and holder are looking more and more cooked.

Ted,

Most of the time I'm way off base, but every now and again I get lucky. As the classic registrar, I bet you have a late model 93.

If you have those PAL fuses adjacent to the positive battery terminal, take a look at them, especially the yellow ignition one. I had a similar intermittent no start condition when corrosion and then the heat generated from poor fuse connection took its toll. The fuse was good but the terminals were fried. There's a photo kind Art posted for me somewhere in the archives.

Marty Wolfson

Proud member of the 300K club

Yeah, that fuse block has been an ongoing headache. It's pretty well cooked. I've replaced it once and replaced that yellow fuse several times. I replaced a section of wiring too, although I don't think I've actually replaced the connectors themselves. When that yellow fuse is pulled out it cuts power to the radio and other things as well. When I have the no crank issue everything else seems to work so I didn't condemn the fuse block as a result . However, I have kept a suspicious eye on it.

At this point I'm not sure what to do as the fuse block part itself is no longer available and even the fuses are hard to find (Tasca no longer has them for example). I have been thinking about cutting that whole fuse block out of there and replacing it with some sort of make shift setup from AutoZone. Maybe it's time to do that to rule this out. Or as Art suggested, maybe I need to pack my test light to do some more diag when it happens.

Somehow we ended up with a bit of a Volvo collection here and the '93 doesn't get driven quite as often. It's in such nice shape that we don't really like taking it to parking lots, etc. However, when it does get driven my wife tends to drive it most often. Rather than complaining she has become accustomed to hanging out for a while when the no start happens. People come over to her to offer help and she sends them away perplexed after telling them the car will start in 10 more minutes. I'm only back on the case because we took the car on a 2K mile trip this week and I got to experience the problem myself 3 or 4 times.

fyi,... I haven't been doing the Classic Register for a while. I had passed it on to another willing volunteer.

Put a gauge on the fuel rail and look for residual pressure after turning off the car. It should hold some for at least 20 minutes to keep the fuel from boiling.
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Art Benstein near Baltimore

When you've seen one shopping center you've seen a mall.

I could certainly do that, but would it explain the no crank condition?

I found Ted's old post from 3 years ago. The same issue was resolved by having the starter replaced, according to the final wrap in that thread. Explains the "new" starter well enough to know whether it is newer than the issue.

When it was being diagnosed, Ted did see the voltage at the solenoid. And, by looking at the wiring diagram, I can see the yellow fuse would not be involved if Ted can see the dash warning lights while the ignition switch is in position III.

https://www.brickboard.com/RWD/volvo/1538093/220/240/260/280/intermittent_nostart.html


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Art Benstein near Baltimore

Marathon runners with bad footwear suffer the agony of defeat.

Thanks for finding that post. Being an intermittent problem it caused me to have false hopes that it was fixed at the time, especially heading into cooler weather.

Sorry, I'm not very sharp at night.

You might jump right to the trouble if you have the PAL fuses and you take Marty's suggestion.

If not, I don't trust what one might call a "new" starter to have eliminated it as the reason. I'd get a test light ready for when it happens again to see if you are getting the voltage from the ignition switch to the solenoid (small spade lug on starter).
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Art Benstein near Baltimore

Santa's helpers are subordinate clauses.