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Discussion Starter · #1 ·
Hello all,
this is my first post on this forum. I look forward to hearing from you, I live out in San Diego area.
I recently picked up 99 suburban with 135K clean body with a 454 that was running rough. I was able to get it for 925 so I dont have a lot invested in it.

when I got it home it had three codes, TPS, and coolant sensor, and P 0302 cleared the first one and then got the P 0300, pressure tested got 30 in the #2 so I took off the heads. I gave it a valve job. history of the truck apparently the kid had over heated it and caused a valve to gall then bend. He put in a new radiator but failed to really flush it well. anyway, I put it all back together. New wires, plug, cap, rotor, fuel filter, TPS, oil.

Iam not getting any codes, but I feel pretty confident I got the distributor pretty close. but again, no codes.

Initially it would start but stall as soon as I let go of the key. I looked around found two items I had meant to get back to that I missed. Tightened them up and was able to at least get the truck to idle.

Now she stays running but the idle fluctuates and when I hit the accelerator it hesitates.

I thought it might be the IAC acting up so I checked it out, it looked pretty grubby so I ordered a new IAC from amazon it will be here tuesday, but I dont really have a smoking gun.

Can anybody think of something else it may be?

By the way, I normally go to Auto Zone, and... Amazon is half the price in many cases if you got the time to wait for the part. I paid 108 for gasket set that auto zone wanted 175 or something. anyway.
 
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Hope ya get it figured out and back on the road,, ya gotta beast and sounds like at the price well worth putting some time and money in!! Good Luck!
 

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Discussion Starter · #3 · (Edited)
Its not the IAC, so I cleaned the MAF sensor real well, seems to help, but still got a little roughness, maybe a loose spark plug wire. At least the fluctuating stopped. more or less, but the exhaust smells rich.
 

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Discussion Starter · #4 ·
OK, update... grrrr. So I replaced the MAP, no change. I talked to mechanic buddy he said it sounds like a vacuum leak. So i sprayed some brake fluid on some possible areas, one of the components had bad threads, when i put in so what I couldnt see from afar was that the screw was not all the way down causing a vacuum leak. So i pulled rethreaded the holes and reattached. No more fluctuating idle, but runs like #$%%, rough.

Timing?
Some other random sensor?
i have changed the IAC, MAP, and have all new plugs and wires. Cleaned the MAF

Rrrrr. thanks
 

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Discussion Starter · #6 ·
No, but I have only run it for maybe a half hour total, not on the road.
 

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Hows the distributor?
 

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Discussion Starter · #8 ·
Well, I think its ok, its a mother to get to.
I put some fuel injector cleaner in it today, I will clear a path out of the yard and take her for a spin tomorrow, maybe there is some junk in the injectors.
 

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Discussion Starter · #9 ·
Ok, well... Still rough on idle and acceleration. At least I am getting a code now. P0300 yay!! not.

I am wondering now if my timing was off; would I only get the P1345 code or could I get both P0300 and P1345 or would it be one or the other?

Do I need to drive this many miles to get the P1345 code to show, or would it have already showed up when the P0300 showed?

I am trying to avoid going to a dealer or mechanic that has the scanner to adjust the cam retard.

I also looked on my scanner at sparkadv and it shows 29 degrees at 2000 rpm, is this something I should be looking at? I'm guessing it is irrelevant.
 

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Discussion Starter · #10 ·
Yay mystery solved.
So know those silly heat guards that protect the spark plug wire? Well those make it difficult to get a good snug fit on the plugs, I thought I had gotten them on well, until I kept coming back to wires and plugs are the problem. One by I made sure to get the little "pop" when they go on right.

Runs Smooth as a babies butt.

Thanks for all your help, and if nothing else giving me a place to vent.
 

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Yay mystery solved.
So know those silly heat guards that protect the spark plug wire? Well those make it difficult to get a good snug fit on the plugs, I thought I had gotten them on well, until I kept coming back to wires and plugs are the problem. One by I made sure to get the little "pop" when they go on right.

Runs Smooth as a babies butt.

Thanks for all your help, and if nothing else giving me a place to vent.
Ha ha...that is awesome! I love it when there is nothing really wrong, we just have to get out of our own head. Enjoy a great weekend drive!
 

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Is there a certain way you have to set the timing on the 454 7.4l efi engine. Putting in new head gaskets and intake gaskets. Getting ready to start reassembly and don't know if I need to bring the no#1 cylinder to tdc and install the distributor facing the no#1 cylinder like old school.
 

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Discussion Starter · #13 ·
Yes for sure,
#1 TDC needs to be on the compression stroke., you can tell because when you are turning it through the valves will be closed even after it passes TDC, other wise the intake will be open,

There are some notches on your distributor, a dot and a line on the side near the bottom near the spline portion, line those up the dot and the line, I think they are yellow marks.

when you drop it in, the spline will turn and what youll see is that it moved the rotor, ultimately you want the mark on the rotor to be pointing at the "8" notched in the distributor on the top.

I found a cool video on how to do it it explained the dots better, But ultimately the goal is to have the number one in TDC and rotor pointing at the "8"

One thing you should do before you get all the intake housing back on is to align the distributor prior to and understand whats happening back there. what you are aligning is the oil pump that attaches to the distributor, there is a slot that the bottom of the distributor needs to align with the top of the oil pump, you'll have to dink with it, but the goal there is when you drop in the distributor the slot lines up with the tab on the distributor, it is way easier to do this with the intake manifold off than it is to mess with once the manifold is in,, the slot is kinda far down the hole, its just easier to do that way,

take your time make sure its in right, you dont want to go back later. be as exact as you can.

Good luck.

P Dub
 
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Hello all,
this is my first post on this forum. I look forward to hearing from you, I live out in San Diego area.
I recently picked up 99 suburban with 135K clean body with a 454 that was running rough. I was able to get it for 925 so I dont have a lot invested in it.

when I got it home it had three codes, TPS, and coolant sensor, and P 0302 cleared the first one and then got the P 0300, pressure tested got 30 in the #2 so I took off the heads. I gave it a valve job. history of the truck apparently the kid had over heated it and caused a valve to gall then bend. He put in a new radiator but failed to really flush it well. anyway, I put it all back together. New wires, plug, cap, rotor, fuel filter, TPS, oil.

Iam not getting any codes, but I feel pretty confident I got the distributor pretty close. but again, no codes.

Initially it would start but stall as soon as I let go of the key. I looked around found two items I had meant to get back to that I missed. Tightened them up and was able to at least get the truck to idle.

Now she stays running but the idle fluctuates and when I hit the accelerator it hesitates.

I thought it might be the IAC acting up so I checked it out, it looked pretty grubby so I ordered a new IAC from amazon it will be here tuesday, but I dont really have a smoking gun.

Can anybody think of something else it may be?

By the way, I normally go to Auto Zone, and... Amazon is half the price in many cases if you got the time to wait for the part. I paid 108 for gasket set that auto zone wanted 175 or something. anyway.
Make sure the diaphragm in the fuel regulator isn’t torn but sounds like and old Chevy fuel pump issue. If it sputters under load or during idle when the a/c is on I’m better your pump has a tiny tear in it, meaning it will provide fuel to the engine but not the correct mixture under load. When you accelerate I’d imagine it doesn’t like to shift or accelerate until the throttle is let off.
 

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