97 K1500 fuel pump and engine issue

[bbullsj]

I was driving to work and my 97 K1500 with the vortex 5.7 was running fine. It hesitated a couple times during light acceleration after less than 3 miles of driving it. I got work, turned it off and by the time I left, it started up fine but then had the same issue within a couple miles. The next morning I had a check engine light and when it happened and I decided to turn the truck off and start it back up. It would not start. I disconnected the battery thinking to clear the CEL and reset the computer but nothing. After 45 minutes of trying I finally held the gas pedal to the floor while cranking and it sputtered to life. It drove like crap, and would not idle at a stop.

I checked fuel pressure and with the key turned on it went to 60psi but within 3-5 seconds it flatlined. I also noticed more oil than usual that had leaked from the truck. The rear of the lower intake has been seeping for about 6-7 years, just hadn't replaced the gaskets yet. I checked the oil level and it was at the top of the fill line, which I found odd because I hadn't topped it off in a while so it should've been low. I check codes with a Tech2 and found both bank HOS2 codes and 2 coolant temp sensor codes. (like an idiot I didn't write them down and erased them. I put a new fuel pump and assembly in it and a new coolant temp sensor. The truck started up kind of rough but once the gas pedal was pressed once it idled and ran fine. It runs great now, no smoke, no hesitations but still starts rough and sounds like it is missing until you hit the gas quick once and then it's fine until you shut it off.

I filled the gas tank up and then drove it around a little bit. I drove 70 miles running errands before I got back home and had burned through 3/4 of a tank (25 gallons) of gas. I have no idea where it's going! It isn't burning it and i'm not leaking any from the tank or lines. I let it sit a day and someone suggested that it could be going past the rings and into the crankcase and that's why it's leaking more now. Thinning out the oil and getting through the gasket easier. Also makes sense because after I let it sit for a day i check the oil level again and it was an inch down from the top. If that much gas was getting past the rings wouldn't I see smoke coming from the tail pipes from unburnt gas? I'm not sure what to check next and with winter coming can't be without the 4x4. The truck has the original engine and it has 196k on it. I know the engine is worn and i've been working on getting it replaced but now I feel almost like I have to.

So, bad rings? Stuck open injector or poppet valves? Any directions of what to check next would be of great help.

[maxwedge]

Sounds like the injectors or spider/regulator under the upper intake iis leaking. Common issue on the Vortec.

[rhandwor]

I would retest the fuel pressure the regulator maybe going bad to start vacuum can suck in gas with a blown diaphram. Leaking intake gaskets also cause problems.

[j cAT]

""I checked fuel pressure and with the key turned on it went to 60psi but within 3-5 seconds it flat lined "" well if that means 60 psi then rapidly drops to zero that means unregulated fuel dumping into the engine with what you say on the other observations. my guess is the regulator/injector assy defective. runs ok above idle but not at idle too much fuel and oil being diluted creating your oil leak to increase much more .. as was mentioned these fail , common .

[bbullsj]

So I think will almost 200k on a never touched engine I'm probably looking at the injection system is bad. I did some more reading about what would dump so much gas into the intake and like rhandwor said, the diagram could be defective and dumping gas into the crank case. Hence the reason my oil level was high and why more oil is leaking out, because it's thinner.
I did a lot of reading about the upgrade from CSFI TO MPFI and it looks like that migth be the way I go. Has anyone heard anything bad about that swap? I've seen them sold on tons of sites but it looks like everyone sells the Delphi one. Is there any seller that would be better to purchase from?

[j cAT]

Originally Posted by bbullsj

So I think will almost 200k on a never touched engine I'm probably looking at the injection system is bad. I did some more reading about what would dump so much gas into the intake and like rhandwor said, the diagram could be defective and dumping gas into the crank case. Hence the reason my oil level was high and why more oil is leaking out, because it's thinner.
I did a lot of reading about the upgrade from CSFI TO MPFI and it looks like that migth be the way I go. Has anyone heard anything bad about that swap? I've seen them sold on tons of sites but it looks like everyone sells the Delphi one. Is there any seller that would be better to purchase from?

http://www.1aauto.com/multiport-fuel...=507234&y=1997 200K that's good on this old truck of the rust belt.

[bbullsj]

I might not be able to start working on fixing it for about 2-4 weeks. Will it hurt the engine to sit there with gas residue all over inside the engine? Should I drain the oil and put in some fresh stuff and then crank it over a bunch with the fuel pump relay out? Or should it be fine?

[j cAT]

Originally Posted by bbullsj

I might not be able to start working on fixing it for about 2-4 weeks. Will it hurt the engine to sit there with gas residue all over inside the engine? Should I drain the oil and put in some fresh stuff and then crank it over a bunch with the fuel pump relay out? Or should it be fine?

I would drain the oil out .. disable the fuel pump.. crank it a few times oil drained .. then add fresh oil/filter.

remember alcohol fuels are water based .. using conventional oil this would then create sludge deposits not good for the lifters.........

[bbullsj]

Well the part is ordered and on its way. I won't be around the truck and or be able to drain the gas/oil mixed oil from the engine for about a week. Probably run a really good engine cleaner through and do a couple oil changes after I get it running again?

[j cAT]

Originally Posted by bbullsj

Well the part is ordered and on its way. I won't be around the truck and or be able to drain the gas/oil mixed oil from the engine for about a week. Probably run a really good engine cleaner through and do a couple oil changes after I get it running again?

post back how you made out .. good luck .. if the truck is not rusted out keep it as long as possible . new trucks are low quality not long lasting.

[Schurkey]

Originally Posted by bbullsj

I won't be around the truck and or be able to drain the gas/oil mixed oil from the engine for about a week.

No problem.

Originally Posted by bbullsj

Probably run a really good engine cleaner through and do a couple oil changes after I get it running again?

Don't bother. Dump the contaminated oil, change the filter, put in clean oil. Done.

[bbullsj]

I started to take things apart and here's what I've found. I've also found some pitting on the intake coolant gasket surface. It doesn't appear to be too deep but there is some there. Is there anything I could or should do about it?

[bbullsj]

Got it all back together and gave it a good test drive and it runs pretty well. A couple things that concern me. Before this all happened when I would cold start my truck it would have a really nice "bark" so to say when it first started up. It does not have that now. It almost sounds like it rolls out of bed instead of jumping like it used to. Anything I can check to find out what might be causing that? Also, once it shift into overdrive, at about 45 mph and with low load on the engine it has what feels like a dead miss. Not a stumble but for a second it's like all the power is being cut and then it kicks back in. From what I can tell so far it only does it once after it gets into overdrive and then its fine. As soon as it shifts down a gear for any reason and then shifts back into overdrive (slowing down and taking back off or downshifting to speed up) it will do it again. Any ideas on what to check? I do have a Tech 2 available to me. I used it to adjust the cam retard to 0 degrees.

I know all the computer will have to relearn their parameter so maybe it's that? Doesn't seem right though.

[j cAT]

Originally Posted by bbullsj

Got it all back together and gave it a good test drive and it runs pretty well. A couple things that concern me. Before this all happened when I would cold start my truck it would have a really nice "bark" so to say when it first started up. It does not have that now. It almost sounds like it rolls out of bed instead of jumping like it used to. Anything I can check to find out what might be causing that? Also, once it shift into overdrive, at about 45 mph and with low load on the engine it has what feels like a dead miss. Not a stumble but for a second it's like all the power is being cut and then it kicks back in. From what I can tell so far it only does it once after it gets into overdrive and then its fine. As soon as it shifts down a gear for any reason and then shifts back into overdrive (slowing down and taking back off or downshifting to speed up) it will do it again. Any ideas on what to check? I do have a Tech 2 available to me. I used it to adjust the cam retard to 0 degrees.

I know all the computer will have to relearn their parameter so maybe it's that? Doesn't seem right though.

The 45MPH issue would most always be the transmission lock up solenoid. I would put a bottle of transmedic transmisssion conditioner run it a few hundred miles then drop the pan and replace filter fluid.

ONLY USE DEXRONVI NOT DEXRON III................

ENGINE SHOULD NOT BARK . should start quiet and smooth .

[j cAT]

Originally Posted by bbullsj

I started to take things apart and here's what I've found. I've also found some pitting on the intake coolant gasket surface. It doesn't appear to be too deep but there is some there. Is there anything I could or should do about it?

the use of marine tex works with pitting. intake does not get 400 plus deg f. I have used this product before on damaged metal with seal surface corroded [boat engine]..