1990 D150 engine surging when idle or driving (part of the time)

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Deblackmon3

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1990 D150, LA 318. On cold starts, the engine will either start then surge for maybe half a minute, or not even start at all. When the engine is hot (sitting in a parking lot for ~8 hours in 95 degree weather) it normally starts with no problem.

When in drive, if I have don't have my foot on the gas under 30 mph, the engine surges. If I go over 30 and let go of the gas, the engine acts fine, then as soon as I go under 30 again it surges. Constant gas flow stops the surging, but I don't want to have to keep the gas flowing to stop it.

It is really sporadic when it decides to f**k up. Sometimes, it'll idle perfectly for 5 minutes then start surging, or it'll start surging immediately and then level off.

_____________________
Possible issues that I think could be the problem (or multiple):

O2 sensor
dirty carb
faulty spark plug wires
bad spark plugs
MAP sensor
Cylinders filled with crap/damaged pistons
 
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Deblackmon3

Deblackmon3

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Update: I got the truck as a gift, and the odometer doesn't work so I basically forgot to change the oil and filter for about two years.... didn't change it when I got it from sitting for several years... hehehe.... :(

I changed the oil and filter, and God it wasn't even oil anymore. I was killing that engine and I had no idea. My teacher described it as "melted chocolate with sprinkles", but it was pitch black, and poured like spoiled milk. I actually had some oil spill on me and I thought it was going to burn me from how hot it was. It made the steel container we put used oil in too hot to touch. I am ashamed to even call myself a car enthusiast. :puke:

That didn't solve my problem of surging, but I feel like that sh*t took a huge chunk of my engine's life away from me, unless I rebore it or something.
 

crazzywolfie

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the best thing to do to see how much life is left in the engine is to do a compression check. have you checked for codes?
 
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Deblackmon3

Deblackmon3

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the best thing to do to see how much life is left in the engine is to do a compression check. have you checked for codes?

Have not checked codes yet. I'm actually a little confused about the message center, it has an anti-lock light that I had no clue was there because it started showing up this morning. I'll look into do a comp check soon or in the next few hours.
 

crazzywolfie

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i am not too familiar with SC and the weather you get there but you may want to check your steel brake lines. sometimes when they start leaking the brake and abs light will come on.
 
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Deblackmon3

Deblackmon3

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i am not too familiar with SC and the weather you get there but you may want to check your steel brake lines. sometimes when they start leaking the brake and abs light will come on.

Well, I'm not on the coast so I don't have to worry about salt ;) and It hasn't snowed in about 4 years, and maybe 10 more before that. Now, when you mean the lights come on do they stay on or stay for like 2 seconds then turn off? That's how the parking break and abs light acts, then the check engine and maintenance light go off maybe 2 seconds later. Engine oil light goes off after 10 seconds or so.
 

crazzywolfie

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i am not sure. i just know if the brake light and abs light stay on a bit longer than they normally do then it is possible that a brake line is leaking. you can check brake fluid levels every so often and you should be able to tell. i know i had a line with a very slow leak up to the day that it blew.
 

dodge dude94

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Update: I got the truck as a gift, and the odometer doesn't work so I basically forgot to change the oil and filter for about two years.... didn't change it when I got it from sitting for several years... hehehe.... :(

I changed the oil and filter, and God it wasn't even oil anymore. I was killing that engine and I had no idea. My teacher described it as "melted chocolate with sprinkles", but it was pitch black, and poured like spoiled milk. I actually had some oil spill on me and I thought it was going to burn me from how hot it was. It made the steel container we put used oil in too hot to touch. I am ashamed to even call myself a car enthusiast. :puke:

That didn't solve my problem of surging, but I feel like that sh*t took a huge chunk of my engine's life away from me, unless I rebore it or something.

:mfr_omg: :****:

Just keep an eye on it and change it as soon as it gets black or gets even close to black. If necessary, when doing the change, substitute a quart of oil for a quart of ATF+4. That will knock out most of the sludge in the engine, but may move some stuff that doesn't need to be moved or will cause various seals throughout the engine to leak. :hidesbehindsofa:
 

crazzywolfie

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my truck got the gas treatment thanks to the previous owner blocking the gas tank vent line. pretty much filled the engine full of gas. for some reason i think it helped my compression but ATF is probably a better idea. i think i have heard it is also good to help rejuvenate the seal.
 

dodge dude94

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I, personally, may end up doing that with the 76 if the oil gets too dirty too quick. lol
 

crazzywolfie

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oil in carburated engines seems to turn black a lot quicker than in a fuel injected engine.
 

dodge dude94

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Too fat maybe? I haven't pulled any plugs, but I know I'm running a tad fat, something that's been exaggerated setting the advance on full vacuum..



Crap, THREADJACKING BATMAN!! :D
 
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Deblackmon3

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Too fat maybe? I haven't pulled any plugs, but I know I'm running a tad fat, something that's been exaggerated setting the advance on full vacuum..



Crap, THREADJACKING BATMAN!! :D

Haha it's all good, thanks for the ATF-4 tip, I'll have to try that soon (or just drain a little oil out tomorrow and put some in)
 
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Deblackmon3

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Updates!

~~~~~~~~~~~~~~

The surging has gotten to the point of being constant, unless my foot is on the throttle.

Every time I drive the engine overheats, guaranteed. The plastic tip to the overflow tank actually melted by how hot the steam is. I have a radiator cap with a latch on it that can be lifted to release steam; it doesn't release JUST steam though, coolant legitimately spits out of the hose and has the force to go several feet from the car.

I'm running a lean mixture, which doesn't make the overheating help at all.

I lose almost half a gallon of coolant every day. I have to carry around a container full of water to top off the radiator every time before I start the engine.

deblackmon3-albums-pictures_9_16_13-picture11611-coolant_got_so_hot_radiator_overflow_melted_shut_overflow_container_i_need_get_my_engine_fixed_fast.jpg


Some of the things I need (updated):

Water Pump
Fan Clutch
Fan
Thermostat
Headers
Breather cap
Freeze Plugs
I MIGHT need a radiator, I don't know yet if I can salvage and repair it.
valve covers
Pistons
Crankshaft
Definitely new gaskets everywhere
Cylinder heads
Oxygen Sensor
Whatever controls the cruise control
Fuel gauge
exhaust manifold
AC compressor

Basically I need to replace everything except the block. Which I'll probably have to rebore anyway.
 

dodge dude94

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It heats up after a little, so it's not receiving any coolant. It doesn't matter if I'm on a short drive or drive with really low RPMs, It overheats regardless.

Sounds like your block is plugged up or the water pump is ****.

I'd stop driving it if I were you. Not worth nuking the engine.
 
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Deblackmon3

Deblackmon3

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Sounds like your block is plugged up or the water pump is ****.

I'd stop driving it if I were you. Not worth nuking the engine.

That's what I was thinking of doing. I know the water pump is ****, it's leaking everywhere. I lose gallons at a time. About to go on Summit right now and order one.
 

dodge dude94

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That's what I was thinking of doing. I know the water pump is ****, it's leaking everywhere. I lose gallons at a time. About to go on Summit right now and order one.

As crazzy said, check Rockauto first. Summit may have free shipping, but the difference in part prices will likely negate that. Just watch your shipping charges in Rockauto. Because of the way they're set up, it ships from multiple warehouses, so the shipping might cost more than normal.
 
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