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Discussion Starter · #1 · (Edited)
'99 Suburban C1500 5.7, all stock, 160k miles. (GMT400)
Usually, I barely look at the key and it fires right up. Runs great, mileage and power are normal, which is to say I can surprise Mustangs at stoplights and I get between 12 and 14 in town and 20-22 highway.

But...from time to time, beginning a few months ago, if I kick the starter over before the fuel pump fully pressurizes, she won't start. When it began, I would have to wait about ten minutes, then all was well again. Then just before Christmas, she just croaked. Sat for three days before she would start again. Then if I let the pump charge first, all was well. Pump finally died. I knew it was coming because of the above.

I replaced the pump...just the pump, not the entire assembly. (I didn't have a couple hundred bucks when the pump itself was $40!) Ran fine.

Ok, the root of the problem: When it has to crank, I get maybe three or four rotations (you know,. rwrr-rwrr-rwrr sound) then all electrical goes out. I thought maybe my starter is sucking too many amps, a high resistance scenario. This has been the case since this whole story started a few months ago, just the truck would start eventually then.

If I jump the truck, it nearly stalls my wife's Jeep when I crank and still cuts out. The battery is about shot, I am sure. Its from 2010 and I live in the desert. If I fully charge the battery with a trickle charger, it charges right up, but still does the same cranking cut-out thing.

I put my multimeter at the fusebox on the feed cable from the battery and a chassis ground. I get full battery voltage at the terminal, in this case it was 13.6 with my Dad's Ranger hooked up with jumpers (yes, from his battery to my positive terminal and chassis ground). Same cranking behavior. Volts went from 13.6 at rest to a low of 7 or 8 while cranking with zero when it all cuts out.

Tonight I am getting the battery tested and renting a fuel pressure tester, but when she starts, she runs great...but I am in a no-start scenario now, so I want to be certain the pump is putting down full pressure. Also going to see if I can borrow my neighbor's battery from his K1500 and see if just a different battery might work. (Internal short in my batt?)
 

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Sounds more like an intermittent open in the battery. An internal short would probably heat up the jumper cables a lot - might even see smoke and melted insulation. I'm bettin' a temporary swap with the Jeep battery or the neighbor's should crank it up.

Still a chance it might be Pos or Neg battery cable. But I think the battery. Not lately but I've seen'em so bad the Pos or Neg post would spin around without much effort.

Good luck
Ted
 

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I suspect the battery as well, maybe one, or two, dead cells.

If the battery tests ok, the high resistance you spoke of is the problem. Look for dirty connects, maybe loose, at all of the larger wire ends. Also check the conndition of those cables, for internal damage.

EDIT: Haha, looks like Ted beat me to the answer.
 

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Discussion Starter · #4 ·
The battery was shot. Replaced that and it cranks now, but still has a small, intermittent hesitation when it cranks.

Still will not start. Plugs are wet. I got some grey vapor out of the tailpipe. It tried to fire a few times but didn't catch.

In checking the plugs, one of the wires broke, so new wires, cap, rotor and plugs just went on the list. Its been 60k miles since they were done.

Tomorrow I'm renting a pressure guage to make sure thats good.

Still no codes either.
 

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Discussion Starter · #5 ·
Update: Last night we stuck a pressure tester on it: 62 PSI cranking, dropped to 55 and held fine.
So we started testing spark after replacing the broken plug wire. Cranked a bit, spark didn't look real good to me, so I re-positioned it to a better ground, tried again and she started! Shut it down, plugged everything back in, put the air intake back on and she fired right back up.
Idle was rough but it smoothed out. I revved it a bit (I only go to about 2500 on a free rev...I don't want to risk hurting anything and my neighbors gripe at the slightest thing!)

So she smoothed right out after a minute or two. Got back to the whooshing rev sound I am used to. Took a ride to take the tester back and try it out: she drove just fine...as always, but good test result.

So here is what I think happened: The bad battery got me jittery and was the root of the initial problem.
My old pump was bad, I do not doubt. Its been three years and a LOT of miles, so it was about time for this particular truck. I've owned it long enough to have done three pumps now, about every three and a half years. (I think it's about time to do that hi-po framerail pump conversion!)

After I swapped this pump, the internal fuel line popped off twice, so I'm guessing I got air in the lines, then I was babying it pretty bad...I usually drive rather aggressively, so I think between the sedate driving style and air in the line, it starved out, then the crap battery failed so it stayed starved. Once I did a lot of cranking testing the pressure and the spark, it reprimed and flushed it out.

The big test is tonight and tomorrow morning to see if she re=starts reliably.

I hope so...I'm driving a borrowed sun-faded red Mustang (it looks pink) with "April" on the side....

...and my teenager's Jeep TJ is having problems...again...so I gotta move on from this one!
 

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Discussion Starter · #8 ·
Should have never said it was fixed. Wouldn't start again to night.
Same issue: cranks fine, getting spark, fuel smell, no start. Starting fluid did not help.
Seems to happen on Sunday night when I haven't driven it since Friday afternoon and it is cold and wet out and I'm in a hurry and don't let the pump build pressure for a few seconds before I try to start it.

I put new plug wires on and cleaned the cap and rotor tonight. Trying to test spark I got good spark on #1, but none on #3, so I did the wires (which I had on hand). Tough to be definitive as I was working alone.

Strange thing is I'll bet it will start in a few days. Usually does. Acts like it is flooded but it take two or three days at lest for it to clear. I'll retest the fuel pressure but it won't start on spray either.

Maybe aiflow sensor or an intermittent spark control chip? I read some mention of a sensor under the dist rotor, but it didn't say what it was.
 
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