Rough Misfire and P0300, likely due to water in the fuel - 1998 Chevy K1500 P/U, 5.7
October 31st, 2014, 3:08 PM
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Rough Misfire and P0300, likely due to water in the fuel - 1998 Chevy K1500 P/U, 5.7
Hello everyone,
My '98 K1500 (Silverado) is having some pretty gnarly misfire issues and I'm pretty sure I know what caused it (and is continuing to do so). The misfires are of the random type and produce a P0300 code, if I remember right.
I really would like to see if there are any possible solutions however.
My situation is as follows:
2 weeks ago, my vehicle began to stall on me intermittently on an attempt to make a short outing. Immediately, I turned around and made it to a local Firestone, which happened to be within walking distance of the house. I told them what was going on and that I was also getting a Crankshaft/Camshaft correlation code and a Rich fuel mixture code, although I do not remember those codes exactly. They said they could fix the issue fairly quickly and that I would likely see my vehicle the next day.
I get a call the next day, telling me that my vehicle was ready and that they had made the following adjustments:
This was over the weekend. The pickup ran fine until Wednesday afternoon after work, when it just stalled on me at a red light after applying pressure to the brake. At this point, I made the assumption that the fuel pump must be going bad because Firestone also charged me for a diagnosis of the original problem and I thought "surely they would have caught it if it were anything else".
After calling Firestone and getting a quote for a fuel pump replacement, I nearly sh*t myself and said "No thank you". My funds where beginning to get low at the time anyway so I began searching for an alternative. I thought, "I can take the bed off, which would require man power" or "I could try and drop the tank but I don't want to spend extra money on a floor jack or jack for the truck to sit on while I do the job".
My "Aha" moment came when I found
explaining how to make a nice cut in the bed and easily replace the fuel pump without having to lift the bed or drop the tank. I went for it. Like the guy in the video, I ran water over the top of my fuel tank to prevent any spark from my saw blade from contacting any stray fuel or burning my fuel lines.
My project seemed like a success because I made the cut and had replaced the fuel pump from the top of the bed.
The horror started when I attempted to start the truck. The truck would not start. I made one attempt after another, trying not to wear too hard on my starter. I tried until my battery went dead. Inevitably, I ended up having it towed to Firestone. BTW, I had credit there so financially, they where my only option at the time. The next day, they called and said, "Your fuel pump is bad". "Impossible" I said, as I had just replaced it and heard it hum when I turned they key. The mechanic told me that somehow water had gotten into the tank and it spoiled the new pump and that they would need to replace the pump and drain the fuel tank. Yes, it was because I ran water over the tank to keep spark from hitting it.
The did the following:
Drained the fuel tank
Replaced the fuel pump
Flushed the fuel rails
They told me it would run rough and would likely take a while to burn any remaining water out of the engine. Otherwise, bring it back ($$?).
So here I am now. Last weekend, I went ahead and replaced the spark plugs again in case one of them had fowled up. I also purchase 3 bottles of ISO HEET, pouring one of them into my tank yesterday as I filled up.
Now, I'm not sure if there is still water in the fuel tank, rails or if it's stuck in the engine but I'm out of ideas at this point. Maybe I should give it some time, as the guy said it might take a while for the engine to straighten out. I'm getting a P0300 of course, due to misfire but I know it not just on one cylinder.
Should I let the motor straighten it's self out (perhaps its burning off the water) or is there anything else I might be able to do myself? Like for example, remove the plugs a fuel pump relay and just turn the engine?
My '98 K1500 (Silverado) is having some pretty gnarly misfire issues and I'm pretty sure I know what caused it (and is continuing to do so). The misfires are of the random type and produce a P0300 code, if I remember right.
I really would like to see if there are any possible solutions however.
My situation is as follows:
2 weeks ago, my vehicle began to stall on me intermittently on an attempt to make a short outing. Immediately, I turned around and made it to a local Firestone, which happened to be within walking distance of the house. I told them what was going on and that I was also getting a Crankshaft/Camshaft correlation code and a Rich fuel mixture code, although I do not remember those codes exactly. They said they could fix the issue fairly quickly and that I would likely see my vehicle the next day.
I get a call the next day, telling me that my vehicle was ready and that they had made the following adjustments:
- Replaced Crank Sensor
- Replace Spark Plug Wires
- Replaced Spark Plugs
This was over the weekend. The pickup ran fine until Wednesday afternoon after work, when it just stalled on me at a red light after applying pressure to the brake. At this point, I made the assumption that the fuel pump must be going bad because Firestone also charged me for a diagnosis of the original problem and I thought "surely they would have caught it if it were anything else".
After calling Firestone and getting a quote for a fuel pump replacement, I nearly sh*t myself and said "No thank you". My funds where beginning to get low at the time anyway so I began searching for an alternative. I thought, "I can take the bed off, which would require man power" or "I could try and drop the tank but I don't want to spend extra money on a floor jack or jack for the truck to sit on while I do the job".
My "Aha" moment came when I found
My project seemed like a success because I made the cut and had replaced the fuel pump from the top of the bed.
The horror started when I attempted to start the truck. The truck would not start. I made one attempt after another, trying not to wear too hard on my starter. I tried until my battery went dead. Inevitably, I ended up having it towed to Firestone. BTW, I had credit there so financially, they where my only option at the time. The next day, they called and said, "Your fuel pump is bad". "Impossible" I said, as I had just replaced it and heard it hum when I turned they key. The mechanic told me that somehow water had gotten into the tank and it spoiled the new pump and that they would need to replace the pump and drain the fuel tank. Yes, it was because I ran water over the tank to keep spark from hitting it.
The did the following:
Drained the fuel tank
Replaced the fuel pump
Flushed the fuel rails
They told me it would run rough and would likely take a while to burn any remaining water out of the engine. Otherwise, bring it back ($$?).
So here I am now. Last weekend, I went ahead and replaced the spark plugs again in case one of them had fowled up. I also purchase 3 bottles of ISO HEET, pouring one of them into my tank yesterday as I filled up.
Now, I'm not sure if there is still water in the fuel tank, rails or if it's stuck in the engine but I'm out of ideas at this point. Maybe I should give it some time, as the guy said it might take a while for the engine to straighten out. I'm getting a P0300 of course, due to misfire but I know it not just on one cylinder.
Should I let the motor straighten it's self out (perhaps its burning off the water) or is there anything else I might be able to do myself? Like for example, remove the plugs a fuel pump relay and just turn the engine?
November 1st, 2014, 11:13 AM
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Hey Codeman,
I had the same code a couple of days ago on my 08 Silverado 5.3....the dealer told me I had gotten a P0300 code, misfire that was causing my rough idle and check traction/stabiltytrak light to come on. The tech found that the #7 plug had fowled out due to PCV blow-by (?) and also valve cover was leaking. Gave the ok to make nessecary repairs. After replacing said items truck now runs as if it was new, the gain in extra power scared me a bit. Tech said he checked twice for new codes and nothing was found.
I had the same code a couple of days ago on my 08 Silverado 5.3....the dealer told me I had gotten a P0300 code, misfire that was causing my rough idle and check traction/stabiltytrak light to come on. The tech found that the #7 plug had fowled out due to PCV blow-by (?) and also valve cover was leaking. Gave the ok to make nessecary repairs. After replacing said items truck now runs as if it was new, the gain in extra power scared me a bit. Tech said he checked twice for new codes and nothing was found.
November 1st, 2014, 3:54 PM
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ChevyTruck55,
I thought it may be 1 or 2 spark plugs causing the issue myself after I got it out of the shop so I changed every plug. Only one of the plugs came out looking like it had anything remotely causing an issue.
Even now after changing all of the plugs, the issue remains. It's hard to say if it's truly electronic or fuel related.
I added that HEET product in the tank the other day. Today I ran Sea-foam into my throttle body in small increments and began noticing small amounts of water exiting the tail pipe. So much in fact that it created a small puddle on the ground.
I don't know. I guess I still have water in the fuel system somewhere or that was simply a by-product of the Sea-Foam. All electronic parts; with the exception of the distributor cap have been replaced. I'm wondering now if this incident could have also somehow effected the distributor as well.
I thought it may be 1 or 2 spark plugs causing the issue myself after I got it out of the shop so I changed every plug. Only one of the plugs came out looking like it had anything remotely causing an issue.
Even now after changing all of the plugs, the issue remains. It's hard to say if it's truly electronic or fuel related.
I added that HEET product in the tank the other day. Today I ran Sea-foam into my throttle body in small increments and began noticing small amounts of water exiting the tail pipe. So much in fact that it created a small puddle on the ground.
I don't know. I guess I still have water in the fuel system somewhere or that was simply a by-product of the Sea-Foam. All electronic parts; with the exception of the distributor cap have been replaced. I'm wondering now if this incident could have also somehow effected the distributor as well.
November 17th, 2014, 10:10 AM
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Update:
So Its been a while since the fuel pump debacle and I'm still getting a misfire.
I'm not sure how I could still have a misfire at this point. Still, the only code that shows on a scan is P0300. I haven't had a chance to check the fuel pressure from the new pump but I'm under the assumption right now that the mechanics that put in the second pump checked the fuel pressure (Firestone Complete Auto)
Over the past couple of weeks, I've replaced or cleaned the following:
Spark Plugs
Plug Wires
Distributor Cap & Rotor
Cleaned the EGR valve (dipped the business end in a bath of Seafoam for a ~2 hours)
Replaced Fuel Filter again
Is is possible for the fuel injectors to be bad at this point? Perhaps the cats?
So Its been a while since the fuel pump debacle and I'm still getting a misfire.
I'm not sure how I could still have a misfire at this point. Still, the only code that shows on a scan is P0300. I haven't had a chance to check the fuel pressure from the new pump but I'm under the assumption right now that the mechanics that put in the second pump checked the fuel pressure (Firestone Complete Auto)
Over the past couple of weeks, I've replaced or cleaned the following:
Spark Plugs
Plug Wires
Distributor Cap & Rotor
Cleaned the EGR valve (dipped the business end in a bath of Seafoam for a ~2 hours)
Replaced Fuel Filter again
Is is possible for the fuel injectors to be bad at this point? Perhaps the cats?
November 22nd, 2014, 8:09 PM
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Solved: Replaced fuel injector "Spider" with new MPFI
Well,
It looks like the issue was with my fuel injection and/or regulator. The water that contaminated my gas could have finally pushed the regulator past the tipping point. Either way, a new ACDelco MPFI assembly from Amazon.com did the trick.
I also got some new Fel-Pro gaskets to re-seal everything.
Today I started it and let it run for a few minutes, shifting to drive and reverse, which where the first signs of the problem before, and there where no misfires and no codes where thrown. Usually, I would get a code immediately after shifting into drive. It would really start bucking then.
I'll get it out on the road tomorrow. Took me a while to do everything, plus it's been raining here in Texas so I really did not feel like driving.
Looks like I may be good to go.
I studied this video on youtube, as it was my first time to do something like this.
It looks like the issue was with my fuel injection and/or regulator. The water that contaminated my gas could have finally pushed the regulator past the tipping point. Either way, a new ACDelco MPFI assembly from Amazon.com did the trick.
I also got some new Fel-Pro gaskets to re-seal everything.
Today I started it and let it run for a few minutes, shifting to drive and reverse, which where the first signs of the problem before, and there where no misfires and no codes where thrown. Usually, I would get a code immediately after shifting into drive. It would really start bucking then.
I'll get it out on the road tomorrow. Took me a while to do everything, plus it's been raining here in Texas so I really did not feel like driving.
Looks like I may be good to go.
I studied this video on youtube, as it was my first time to do something like this.
Last edited by codeman061988; November 22nd, 2014 at 8:12 PM.
November 26th, 2014, 8:59 PM
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I was had the same problem, with the same truck, by accident I found my fix, it turns out that the ac bracket is close enough that the number 1 spark plug that it will arc from time to time & cause a terrible miss, I happened to be looking at it when it did it, or I probably never found it
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December 30th, 2014, 4:41 PM
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look already replaced averything u said here in this thread had the spider injectors replaced still does it here the tricj turn yr key on listen to hummed and turn it off and do it again third time hold yr foot 3/4 way down kept turn it over till it starts for noe till u find it sorry i have a thread under my name i did everything u saiud and other thread mine still not fixed my only option i should have had the fuel regulator replaced but he didnt when i had the spider replaced so iam thinking when it rains cuased high humid made the computer thinking is running rich which it not which why u getting that code..iam thinking the fuel regulater is allowing too much fuel in cuasued the puter shut down so to by pass this like i siad prime it twice hold yr foot 3/4 way down on gas pedal hold it till the truck starts ull have big black smoke and now i did have the cats replaced at triple a muffler shop still does it sorry guys iam still trying get it fixed even i have only 145 thosuand miles feul pupm replaced in 06 at 89 thoudsand miles
May 31st, 2020, 8:07 PM
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Been there...
Hello everyone,
My '98 K1500 (Silverado) is having some pretty gnarly misfire issues and I'm pretty sure I know what caused it (and is continuing to do so). The misfires are of the random type and produce a P0300 code, if I remember right.
I really would like to see if there are any possible solutions however.
My situation is as follows:
2 weeks ago, my vehicle began to stall on me intermittently on an attempt to make a short outing. Immediately, I turned around and made it to a local Firestone, which happened to be within walking distance of the house. I told them what was going on and that I was also getting a Crankshaft/Camshaft correlation code and a Rich fuel mixture code, although I do not remember those codes exactly. They said they could fix the issue fairly quickly and that I would likely see my vehicle the next day.
I get a call the next day, telling me that my vehicle was ready and that they had made the following adjustments:
This was over the weekend. The pickup ran fine until Wednesday afternoon after work, when it just stalled on me at a red light after applying pressure to the brake. At this point, I made the assumption that the fuel pump must be going bad because Firestone also charged me for a diagnosis of the original problem and I thought "surely they would have caught it if it were anything else".
After calling Firestone and getting a quote for a fuel pump replacement, I nearly sh*t myself and said "No thank you". My funds where beginning to get low at the time anyway so I began searching for an alternative. I thought, "I can take the bed off, which would require man power" or "I could try and drop the tank but I don't want to spend extra money on a floor jack or jack for the truck to sit on while I do the job".
My "Aha" moment came when I found This Video
explaining how to make a nice cut in the bed and easily replace the fuel pump without having to lift the bed or drop the tank. I went for it. Like the guy in the video, I ran water over the top of my fuel tank to prevent any spark from my saw blade from contacting any stray fuel or burning my fuel lines.
My project seemed like a success because I made the cut and had replaced the fuel pump from the top of the bed.
The horror started when I attempted to start the truck. The truck would not start. I made one attempt after another, trying not to wear too hard on my starter. I tried until my battery went dead. Inevitably, I ended up having it towed to Firestone. BTW, I had credit there so financially, they where my only option at the time. The next day, they called and said, "Your fuel pump is bad". "Impossible" I said, as I had just replaced it and heard it hum when I turned they key. The mechanic told me that somehow water had gotten into the tank and it spoiled the new pump and that they would need to replace the pump and drain the fuel tank. Yes, it was because I ran water over the tank to keep spark from hitting it.
The did the following:
Drained the fuel tank
Replaced the fuel pump
Flushed the fuel rails
They told me it would run rough and would likely take a while to burn any remaining water out of the engine. Otherwise, bring it back ($$?).
So here I am now. Last weekend, I went ahead and replaced the spark plugs again in case one of them had fowled up. I also purchase 3 bottles of ISO HEET, pouring one of them into my tank yesterday as I filled up.
Now, I'm not sure if there is still water in the fuel tank, rails or if it's stuck in the engine but I'm out of ideas at this point. Maybe I should give it some time, as the guy said it might take a while for the engine to straighten out. I'm getting a P0300 of course, due to misfire but I know it not just on one cylinder.
Should I let the motor straighten it's self out (perhaps its burning off the water) or is there anything else I might be able to do myself? Like for example, remove the plugs a fuel pump relay and just turn the engine?
My '98 K1500 (Silverado) is having some pretty gnarly misfire issues and I'm pretty sure I know what caused it (and is continuing to do so). The misfires are of the random type and produce a P0300 code, if I remember right.
I really would like to see if there are any possible solutions however.
My situation is as follows:
2 weeks ago, my vehicle began to stall on me intermittently on an attempt to make a short outing. Immediately, I turned around and made it to a local Firestone, which happened to be within walking distance of the house. I told them what was going on and that I was also getting a Crankshaft/Camshaft correlation code and a Rich fuel mixture code, although I do not remember those codes exactly. They said they could fix the issue fairly quickly and that I would likely see my vehicle the next day.
I get a call the next day, telling me that my vehicle was ready and that they had made the following adjustments:
- Replaced Crank Sensor
- Replace Spark Plug Wires
- Replaced Spark Plugs
This was over the weekend. The pickup ran fine until Wednesday afternoon after work, when it just stalled on me at a red light after applying pressure to the brake. At this point, I made the assumption that the fuel pump must be going bad because Firestone also charged me for a diagnosis of the original problem and I thought "surely they would have caught it if it were anything else".
After calling Firestone and getting a quote for a fuel pump replacement, I nearly sh*t myself and said "No thank you". My funds where beginning to get low at the time anyway so I began searching for an alternative. I thought, "I can take the bed off, which would require man power" or "I could try and drop the tank but I don't want to spend extra money on a floor jack or jack for the truck to sit on while I do the job".
My "Aha" moment came when I found This Video
explaining how to make a nice cut in the bed and easily replace the fuel pump without having to lift the bed or drop the tank. I went for it. Like the guy in the video, I ran water over the top of my fuel tank to prevent any spark from my saw blade from contacting any stray fuel or burning my fuel lines.
My project seemed like a success because I made the cut and had replaced the fuel pump from the top of the bed.
The horror started when I attempted to start the truck. The truck would not start. I made one attempt after another, trying not to wear too hard on my starter. I tried until my battery went dead. Inevitably, I ended up having it towed to Firestone. BTW, I had credit there so financially, they where my only option at the time. The next day, they called and said, "Your fuel pump is bad". "Impossible" I said, as I had just replaced it and heard it hum when I turned they key. The mechanic told me that somehow water had gotten into the tank and it spoiled the new pump and that they would need to replace the pump and drain the fuel tank. Yes, it was because I ran water over the tank to keep spark from hitting it.
The did the following:
Drained the fuel tank
Replaced the fuel pump
Flushed the fuel rails
They told me it would run rough and would likely take a while to burn any remaining water out of the engine. Otherwise, bring it back ($$?).
So here I am now. Last weekend, I went ahead and replaced the spark plugs again in case one of them had fowled up. I also purchase 3 bottles of ISO HEET, pouring one of them into my tank yesterday as I filled up.
Now, I'm not sure if there is still water in the fuel tank, rails or if it's stuck in the engine but I'm out of ideas at this point. Maybe I should give it some time, as the guy said it might take a while for the engine to straighten out. I'm getting a P0300 of course, due to misfire but I know it not just on one cylinder.
Should I let the motor straighten it's self out (perhaps its burning off the water) or is there anything else I might be able to do myself? Like for example, remove the plugs a fuel pump relay and just turn the engine?
"Ignition Control Module" black thing middle of the screen screw in the top of it got a 4 wire plug plugged into it...
could bring you anywhere from $17.99 - $71.99
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