So I went out to start my truck this morning and the battery was nearly dead, it almost started but alas it didn't.
I hook it up to a charger, it's dead so I leave it for awhile. At 20 amps it charges up pretty fast so it needs replaced anyway but I decided to try to start the truck anyway to see just how weak it was.
Truck cranks and cranks but doesn't start, I let off the key to start position and it shudders and tries to run. Kinda sounds like dieseling but only once or twice with a half second between.
It does smell a little gassy so I'm leaning towards it being flooded, maybe the stock computer setting after the battery is disconnected is very rich? I tried starting it with the pedal on the floor but no change there.
I was flailing about trying to get going early so I miss NYE traffic so I tried it a few times in a short period instead of letting it sit for awhile too.
I'm thinking it's just flooded, but what else could be if it's not? Trying to run with the key in run position is a bit odd if it's not catching in start position.
Vortex with the port fuel injection, running fine when you parked it?
Flooded is sure possible. What kind of temperature? Colder would make it more likely to be flooded.
Those things also have a fuel pressure regulator that ruptures under the intake that pours gasoline out.
On the other side, if they don't have 60 psi, they crank forever.
Plus, let's not forget the goofy flat top distributor cap that will sometimes fail and send all the sparks to cylinder 3, I think.
And the coil driver module that goes out sometimes.
And the crank sensor that fails sometimes. These last two result in no spark at all. The cap results in spark out of the coil, but not out of the cap.
In reply to Streetwiseguy :
Ran perfectly fine until it was parked. It's been about a week and half since it started. The battery is old so I was gonna replace it soon anyway but the last time it started it started a bit slow with sitting as long as it did this time.
It's below freezing up here too so cold as well
I'll let it sit for awhile, charge up the battery and playy new guitar, then I'll try it again
Streetwise nailed it.
60psi is a must. 56psi isn't enough. 58psi maaaybe depending on how accurate your gauge is.
Replace the cap and rotor. Yeah it SUCKS because it's behind everything and under everything else, and it's expensive, but it's a very common failure item so even if you don't need it now, you soon will. They love to crosstalk if they are at all worn, and it gets worse if it's been sitting and condensation set up shop in there. Reuse the old screws that go into the distributor, the thread locker on the new screws will break the plastic distributor housing.
While you have the intake elbow off, yeah open the throttle and look into the intake to see if all of the carbon has been washed away on the passenger side. That's a leaking fuel pressure regulator.
Your issue also could be a failing ignition switch, that isn't sending ignition power when in the start position. Easy to check, look for voltage at the coil while cranking.
Or it might just be a weak battery. Even if it cranks okay, if you don't have at least 9v in the system the computers won't work.
Ok, left it for a half hour and no change to how it wants to start. Battery cranked for a good 2 minutes so while the battery is old I don't think it's super terrible.
It did try to start twice and once literally stopped the starter but didn't start. Smells like gas too after trying for 2 minutes. It also tries to run a bit with it in run postition .To me that sounds like no spark situation since I've got fuel.
I'm gonna charge up the battery, leave it for the night and tomorrow get some parts. Cap and rotor definitely, maybe a new battery since it's a 2019 battery it seems. Regardless if it is the cap and rotor, it seems like a good thing to replace anyway.
Thank you both for the detailed help
Ok update:
Replaced the battery, old battery was worse than I thought because the difference in starting power is amazing. No change in starting problem.
Replaced the cap and rotor, i didn't see cracks or condensation but it's such a pain in the ass to get to that I would like to do that as far in the future as possible. Made a slight change in starting issue, it's trying to start and hiccups a lot more now but still won't catch.
For diagnostic reasons I sprayed in some starter fluid and it changed nothing. No carbon washed off on the throttle either.
No codes at all
Right now I'm thinking weak spark rather than no spark. I'll have to throw on a tester when I have someone here to start it for me while I watch. I'm thinking coil is the most likely next step at this point.
Have you checked to see how much gas got into the oil? I once had one so badly flooded the oil was mostly gas and washed the cylinder walls
In reply to TRoglodyte :
Didn't think to look at that but oil looks good.
Another update, inline spark tester shows a very weak spark so I'm gonna replace the coil.
Antihero said:
Another update, inline spark tester shows a very weak spark so I'm gonna replace the coil.
That would agree with it not firing well while cranking, but doing a little better right when you let off the key and the system voltage increases. I've had times where a slightly hard to start engine hadn't fired and I was going to give it another attempt, but it was close and fired right when I let off the key (depending on the ignition system the spark can get stronger when the voltage increases without starter load and if it was very close to starting that can be enough for it to fire before the engine stops turning).
Strange. I don't remember how the coil gets its power, but these trucks are somewhat notorious for failing wires in the steering column because of where the pivot is, if you're in the habit of popping the column up when you get out. Check voltage to the coil and make sure it's what you expect.
I have a '98 K1500 and can get measurements to compare to if needed.
you already got the cap and rotor sorted, but the distributor on these has a plastic housing. At one point mine cracked and failed, resulting in a distributor shaft that could move up and down significantly. Instant crappy starting and weird running. You can tell by pulling up on the rotor with the cap off, mine had well over 1/4" vertical movement.
Unlikely that the distributor rotated and timing is off, but if your base timing on the distributor is wrong, it will self correct via cam-crank correlation even when the posts in the cap are clocked significantly far from the rotor. There's a fault code for this, but both of my Vortec 5.7s were significantly off and never set the fault. You can tell if this is your problem if there is significant wear or deposits right on the end of the strip on the rotor - the spark is jumping off the corner to get to the cap terminal.
If you think it's flooded, pull the fuel pump relay and let it crank to see if it will start. But I believe >80% throttle during cranking on these enables flood clear mode. I had to use that "feature" when the regulator inside the manifold started leaking - would flood the engine if it didn't fire up immediately, but it would still drive okay once started until I was able to get new parts in.
In reply to gearheadE30 :
Interesting, I'm not sure what is "normal wear " for the truck since I've owned it 3 years and never touched the rotor, so here's a pic and you guys can tell me if it's significant wear.
See all the little spots of stuff on the plastic part of the rotor?
Now look in the cap.
The reason you replace the rotor is because you're already in there to replace the cap. For whatever reason, the caps are very prone to that powdered scuzz sticking around and causing crosstalk when cranking. If not outright becoming electrically porous in all the little passages that turn the firing order into left bank/right bank outputs.
And as an added annoyance, apparently whoever did this last time broke the , what Google tells me is called , The Power Brake Booster Vacuum Tube Fitting and put in in with one half of the holding power. The capitalization seemed........fitting pun intended.
Apparently hard to get to so I have to wait awhile for it but I don't know if it's an issue at all. I noticed it was pretty wobbly and took off the hose clamp very gingerly so I don't think I did it so it's probably been like that since I owned the truck.
How does that even break? It's a twist lock, have to rotate it 90 degrees to get it in and out. I can't fathom what forces would break it there.
Pete. (l33t FS) said:
See all the little spots of stuff on the plastic part of the rotor?
Now look in the cap.
The reason you replace the rotor is because you're already in there to replace the cap. For whatever reason, the caps are very prone to that powdered scuzz sticking around and causing crosstalk when cranking. If not outright becoming electrically porous in all the little passages that turn the firing order into left bank/right bank outputs.
Here's a pic of the cap, I don't really see arcing but I do see a lot of corrosion. You were right, it sucked a lot so I was gonna replace it no matter what it looked like.
In reply to Antihero :
A ha! Now I get what Streetwise was saying about #3.
Chevy distributor installation is always supposed to have the rotor pointing physically at #1 cylinder when the engine is at #1 firing. The coil lead goes to the evens side of the engine on those caps. So #1 is the terminal at about 12:30 in that pic. Going around counterclockwise, 1 8 4 3 6 5 7 2, it's easy to see that #3 goes all the way from the pictured left, around past the center lead, to pictured right. So when the plastic breaks down, the coil lead can send its juice to #3 all the time.
It's a nice happy accident that the setup almost requires 5 and 7 to not be next to each other. If the two wires are run next to each other, 5 can induce voltage in 7 and fire 90 degrees early. Ford even had a TSB for cracked pistons or something at cylinder 8 for the same problem (Ford numbering has 7/8 the same as Chevy 5/7) because of people running the wires next to each other.
Keep those two separated and cross them where they get close.
Pete. (l33t FS) said:
How does that even break? It's a twist lock, have to rotate it 90 degrees to get it in and out. I can't fathom what forces would break it there.
Your guess is as good as mine, it didn't seem to be totally locked in either so maybe whoever did this snagged it with laying on top of the engine to replace the cap?
Its been well taken care of mostly before me but there is some odd things to it. I had a bit of rear end noise and drained the fluid, it was ridiculously thin, like......wd40 thick. So I think that the previous owner was a good ole boy grandpappy that had some weird ideas at times. I got it off a lot and the salesmen didn't know a lot about it.
Cap and rotor look pretty bad, and yes the spark crosstalk thing is real. The rotor does look a bit like mine when I had the distributor body overly advanced, in your pic you can see a lot more of the buildup is on the leading edge of the rotor, and it looks like the cap has matching wear - the posts have pitting that is off to the side rather than having the pits aimed at the center of the cap. Yours doesn't look as bad as either of mine were so probably not your root cause, but your cap and rotor may last longer and you may have a bit better spark if you retard the distributor body a bit.
Ok, new update
New coil is in, the spark is much better but still no start.
I can hear the pump coming on so I sprayed starting fluid once again to no effect.
But after keeping the throttle on the floor for a bit it really was trying to start do I think we are circling back around to " holy E36 M3 flooded". I tried gor a long time to start it so I'm charging the battery up but I'm thinking I should pull the fuel pump relay and see if it'll go.
Anything other ideas?
Pull the fuel pump relay, see if you can get it cleared out and started. The fuel pressure regulator is inside the intake manifold, when they start to leak, it can cause issues like this, and flood clear mode may not be enough to take care of it because flood clear just kills the injectors. The fuel pump still runs, so the leak continues.
Once you get it running again, use a code reader to see where the fuel trims are - if it's aggressively leaning things out, it might be compensating for a leak. If trims are normal, you may have just gotten unlucky and flooded it badly. Cold engine, cold day, a little bit down on compression or injectors that leak a little, plus your weak spark issues and slow cranking, It's definitely possible that it's just flooded and there isn't one big thing that's gone wrong.
Do you have access to any sort of scan tool? I'd be curious to see what the coolant temp sensor is doing. Reading too cold will trigger to much fuel. Maybe unplug it see what happens? Are the plugs fouled at this point?
Ok another update.
Pulled the fuel pump relay, it started right up. Let it run until it died, put the relay back in and it's starting fast now. Also much smoother than ever before so I'm thinking weak spark as been an issue for a little bit.
Here is the fuel trims off Torque right after it started too
Thank you all for your help, I appreciate it
Gearheadotaku (Forum Supporter) said:
Do you have access to any sort of scan tool? I'd be curious to see what the coolant temp sensor is doing. Reading too cold will trigger to much fuel. Maybe unplug it see what happens? Are the plugs fouled at this point?
I can check it again once I go back out, maybe it's the initial reason it flooded or started to flood?
I haven't pulled a plug though.
Ok, let it sit for a half hour and went to restart it, it took a bit longer and started at low rpm, a stab of the throttle and all was fine. Was able to put it in gear without it dying, rev up to 4k for a 10 count without issue.
After it warmed up a bit it seemed fine and started normally. I don't really start the car, let it idle for 2 minutes and then turn it off, only to restart it right away so I don't even know if this is a new issue.
I'll let it sit over night and start it stone cold in the morning to see if that's an issue. I haven't checked fuel pressure yet, and my scanners can't)won't read it so I'll have to grab the gauge from where ever I stashed it to check fuel pressure.
