Just got home from looking at a '89 350 Formula. Car was in decent shape and I could get it pretty cheap. He told me he was having a hot start problem when I talked to him. I drove it around the neighborhood with no problems. I shut the car off and turned the key to see what it would do and all it does is crank. I figure its a problem with spark or fuel. Someone has disconnected the coolant sensor. I was going to plug it back in but the harness clip is totally gone. I want to go back and buy the car but Im afraid I won't get it started again. This situation has me totally stumped.

 

You'll nneed to determine whether you have adequate spark on hot restars. If not, suspect a weak coil and/or HEI switching module.

If the spark is healthy, suspect fuel leakage From an injector(s) or FPR. Does it help to open the throttle a bit while cranking?

 

No, its dead. Just cranks no matter what. I was reading another thread on here where it said it might be an ignition module. Im going to try that and see if it fixes it. Would the coolant temp sensor being disconnected have anything to do with this? I thought that might screw up the ECM.

 

ignition module would def. be my first guess, then id be thinking starter on its way out (heatsoak). vader is right though about checking for adequate spark, you could probably save yourself some money and / or aggrevation (sp?)

 

There's no such thing as "heat soak" on starters. All a starter is, is a chunk of iron with some copper wire wound around it; there's nothing in there that's heat-sensitive. It's a myth, invented to sell extra parts to people who don't understand the real problem.

The real problem is that the stupid miniature Stone Age direct-drive Delco starter on these cars is too weenie to turn the engine over in the first place, unless conditions are ideal; and when the engine gets hot, and wants to fire on every cylinder, the starter can't get up enough speed to overcome the spark lighting off the mixture before TDC. The cyl pressure is strong enough to turn the motor backwards against the starter torque (or lack of it).

But in any case, the car doesn't have that; he says the car cranks but doesn't start. It's not a starter problem. The starter is doing its job (since it cranks).

I'd suspect either the ignition module, or a leaky injector.

Next time you go to look at it, try holding the gas wide open when it does its thing, see if it will start up and blow a huge cloud of black smoke when it does. If so, you know it's an injector issue, and they need to go to www.cruzinperformance.com for service.

 

The CTS on the water neck is not hooked up? That will cause the engine to run rich in open loop mode which coupled with a leaky injector could be why it doesnot want to start. I would just stick the wires into the sensor with out the clip for now to see if that helps. (Thats how my car was when i got it )

 

I say Ignition Coil 100%.
How often do these need chaning anyways? Is there a set interval?

 

Thanks a ton guys. I should have the car here at my house by the middle of the week. He told me that it has a brand new coil (which it did look new) but he said he didn't know anything about changing an ignition module. I'll try that first. I was going to reattach the water temp sensor but I couldn't find the harness or even where there used to be a harness anywhere. I'll figure that out later. Thanks again.

 

I hate to open up this can of worms, but our starters do have a "heat soak" problem (it's not the cause of this starting problem, I'd guess coil or more likely the module), I've experianced it personally, it's caused by unlike metals expanding and, the increaced eletrical restance that happens when you heat copper wire up, this coupled by worn brushes or contact points in the solnoid causes the power of the starter to drasticly drop off to the point where it won't even run with no load, we tested this on my car in an auto class I took in collage, my car started fine when it was cool, but it woulden't turn over when it got hot, so while the engine was hot we took off the starter and tested it on the bench tester, it maxed the analog gauge out for amps draw and bearly spun, we then waited to the next day and re-tested it cool, (I was changeing out the tranny at the time, so the starter stayed on the bench, the only change was temp) and it drew allitle more amps then the book said it was supposted to (I don't rember the #) and spun fine, we disassembled it and found the brushes were worn and the disk in the back of the solnoid was burned, we put it back togeather and went to Kar Parts (local parts store) and bought a reman. one, the problem went away. Just my $0.02, sorry about the argument this is going to cause

 

Usually when there is an issue with a starter heating up its in the solenoid. I have owned alot of '60s Pontiacs in my days and they are notorious for hot start problems directly related to the starter. A starter either works or it dosen't work. If its cranking at a decent rate the motor will fire as long as its getting spark and fuel at the correct amounts. I just found out I have the day off of work so Im going to cruise over and see if I can get it going and bring it home. I'll let you guys know the outcome.

 

The only reason they have what could be called "heat soak" is because they are inadequate in the first place. In fact, the experiment and data as described above demonstrates that it doesn't exist.

If the problem was the resistance of the copper increasing, then it wouldn't be drawing more current, would it? At least, the laws of electricity in my universe, decree that the data at hand requires the OPPOSITE conclusion to be drawn.

The reason the starter drew more current when hot is probably because the armature was touching the pole pieces.... a typical result of worn bushings. The individual piece in question probably didn't have long to go before it would have stopped working altogether.

I also had alot of old Pontiacs (same starter as a Chevy, just a different shape casting on the end) and never had any unusual "heat soak" problems. Of course, I merely replaced their starters when they got to the point of not starting the car, whether hot or cold; it seemed patently absurd to invent some new "disease" whose description defies the lws of physics, like this mythical "heat soak" thing. I have had 59, 63, 64, 66, 67 Pontiacs; 57, 60, 64, 66, 68, and 69 Chevrolets, that I can recall off the top of my head; a few Buicks from back then; etc. etc. etc. Plus lots of 70s and 80s GM cars with the same inferior design POS starter. They all acted the same.

I'm so glad, after all these years, that someone has finally made it possible to install a halfway modern design starter on these cars. Sticking with that ancient design for so long is an indication of how out of touch GM was for how many years with the real world; i.e. what happened to their cars once they got out of warranty. The trend in recent years, I'd say the last 20 or 25 or so, toward longer warranties, has forced them to address their crappy designs that don't hold up over the long-term and require frequent service. Lots of things have been improved recently as a result. Starters are just one of them. Look at the LT1 starter as an example.

But that doesn't matter..... the guy has a crank / no-start problem, not a no-crank problem. So none of this applies anyway. It's just a rant.