New Motor , Problems right away (4 Viewers)

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Sculpin

Sculpin

Joined
Feb 5, 2024
Threads
1
Messages
5
Location
usa
Hello ,
i just finished up putting my motor in this weekend (rebuild lower and top end )
put 5 gallons of gas and went to give it a start and after some serious cranking this is what i get ,


Not sure where things went wrong but its a very rough idle and if i hit the throttle nothing happens , maybe it comes up 200 rpm and kinda gets better but thats a stretch .
checked with timing light and it doesn't seem far off .
Was wondering what i can look at and check cause i don't really like it running when its this rough with fear of it damaging something .
also its showing no oil pressure which is concerning and I'm not sure why ,
when i took it all apart it had a blown head gasket but it ran well .
HELP
 
Oil pressure gauge looks to be either not working or you have no oil pressure?
Verify this with a mechanical gauge before you do anything else.

Would always recommend you pull the EFI fuse or unplug the coil and crank until you have oil pressure on the gauge before actually starting the engine for a first start.
 
Last edited:
AussieHJCruza said:
Oil pressure gauge looks to be either not working or you have no oil pressure?
Verify this with a mechanical gauge before you do anything else.

Would always recommend you pull the EFI fuse or unplug the coil and crank until you have oil pressure on the gauge before actually starting the engine for a first start.
Click to expand...
Will pulling the EFI 7.5 amp fuse still allow fuel into the engine?

I would also check the cam timing marks.
 
Rwhat said:
Will pulling the EFI 7.5 amp fuse still allow fuel into the engine?

I would also check the cam timing marks.
Click to expand...
No, that's the point of pulling it.

Edit: EFI Main fuse in the main relay block on the fender as per below clarification.
 
Last edited:
Rwhat said:
Will pulling the EFI 7.5 amp fuse still allow fuel into the engine?
Click to expand...
He's referring to the 15 amp EFI MAIN fuse in the fender mounted relay block.
 


Next problem , i pulled the dist cap off this morning and i think it was off by a tooth cause the point was just past the connecter . so re did that and cleaned the connections on the oil pressure unit . showing i have oil pressure but crazy surging when starting
 
IMG_6058.jpg
IMG_6060.jpg



so i pulled valve cover off and my marks on the cams line up and my distributer seems to be in right spot
 
IMG_6057.jpg



something i did notice was that when i line up the cams the dark link of the timing chain is not up top . did i somehow screw that up ?

IMG_6056.jpg
 
Check your sensor connections; I'd bet one's loose or off.
 
HUGE progress


Removed the Tps and she runs .On to the next issues , if you listen is that valve tick ????
Its a brand new oem head that comes with new cams and had machine shop build the whole head . i was told everything measured out . i don't have the feeler gauges so i took their word ( very reputable shop).gonna look around and pray its just something bumping around up top cause i actually don't really know what valve tick sounds like .

2nd Issue - do tps sensors go bad ? it just sat on a shelf while everything was apart .
when taking it off its like spring loaded and hold the throttle slightly open . is this user error when installing ?
seems pretty straight forward 2 little screws line up the paint dots yet here i am .
 
@Sculpin "do TPS sensors go bad?"

Yes, they can (but probably not from just sitting on a shelf for a few weeks??)

If you have a scan tool, even a cheapo wally mart type (and a OBD2 port), start the engine, hook up the scanner to the OBD2 port, and scroll to TPS under live data and read the Percent (at steady idle). It may be something between ?? 6-10% in a warmed engine (idle 650+/-). However if you see zero ( 0 % ) and it doesn't change when you press on the accelerator pedal then (IME) the TPS is either missing, harness is disconnected, bad wiring, TPS is completely dead, or it's incorrectly installed. Check the FSM for details of course.

So yes, the TPS can be installed incorrectly (ask me how I know): This part, IIRC, you have to first open the throttle body butterfly just a bit then push the TPS into the TB. The goal is to get the lever on the TPS on the correct side of the lever on the Throttle body ie: so when you press the accelerator pedal the small lever on the Throttle body is pushing on (rotating) the TPS lever, if that makes sense.

Or to put it another way, you can't just slap the TPS onto the Throttle body, if the Throttle body butterfly is not clocked correctly first when you install the TPS then the TB lever will turn but the TPS (lever) won't (and you'll get 0% for the TPS value on the scan tool with no movement when you press
the accelerator pedal).

One installed correctly I basically clocked the new TPS in the same position as the original, then checked the TPS % and got 8.2 (~650rpm idle) and called it good.

You can check the voltage getting to the TPS at the harness connector, it's in the FSM along with a test sequence and tests that should be done
when you install and set up the new TPS. I didn't follow that because (both) I saw it was bad using the scan tool and adjusted the new TPS using the scan tool.


An actual mechanic may have more to add as I had Covid brain fog when I did this a few months ago so everything I just wrote may be wrong (or backwards) :oops:
 
Last edited:
Kernal said:
@Sculpin "do TPS sensors go bad?"

Yes, they can (but probably not from just sitting on a shelf for a few weeks??)

If you have a scan tool, even a cheapo wally mart type (and a OBD2 port), start the engine, hook up the scanner to the OBD2 port, and scroll to TPS under live data and read the Percent (at steady idle). It may be something between ?? 6-10% in a warmed engine (idle 650+/-). However if you see zero ( 0 % ) and it doesn't change when you press on the accelerator pedal then (IME) the TPS is either missing, harness is disconnected, bad wiring, TPS is completely dead, or it's incorrectly installed. Check the FSM for details of course.

So yes, the TPS can be installed incorrectly (ask me how I know): This part, IIRC, you have to first open the throttle body butterfly just a bit then push the TPS into the TB. The goal is to get the lever on the TPS on the correct side of the lever on the Throttle body ie: so when you press the accelerator pedal the small lever on the Throttle body is pushing on (rotating) the TPS lever, if that makes sense.

Or to put it another way, you can't just slap the TPS onto the Throttle body, if the Throttle body butterfly is not clocked correctly first when you install the TPS then the TB lever will turn but the TPS (lever) won't.

One installed correctly I basically clocked the new TPS in the same position as the original, then checked the TPS % and got 8.2 (~650rpm idle) and called it good.

You can check the voltage getting to the TPS at the harness connector, it's in the FSM along with a test sequence and tests that should be done
when you install and set up the new TPS. I didn't follow that because (both) I saw it was bad using the scan tool and adjusted the new TPS using the scan tool.


An actual mechanic may have more to add as I had Covid brain fog when I did this a few months ago so everything I just wrote may be wrong (or backwards) :oops:
Click to expand...
I would also check that all of your wires to the the TPS are intact and there are no broken or shorted wires.
 
...post #10
 
I never claimed it was.

IF this was a running engine that suddenly started hunting while idling, I'd probably chase wiring as a second troubleshooting option, but that's not this case.

The OP said it was running before he took everything apart, so there's very little reason to suspect a damaged wire. Anything can happen, of course, so that's always a possibility, but it'd be low on my list of things to chase down - especially since he's already found a TPS problem.
 
Sculpin said:
HUGE progress


Removed the Tps and she runs .On to the next issues , if you listen is that valve tick ????
Its a brand new oem head that comes with new cams and had machine shop build the whole head . i was told everything measured out . i don't have the feeler gauges so i took their word ( very reputable shop).gonna look around and pray its just something bumping around up top cause i actually don't really know what valve tick sounds like .

2nd Issue - do tps sensors go bad ? it just sat on a shelf while everything was apart .
when taking it off its like spring loaded and hold the throttle slightly open . is this user error when installing ?
seems pretty straight forward 2 little screws line up the paint dots yet here i am .
Click to expand...

is the cam gear spring under tension? did you remove the "service bolt"?
 
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