2.5 head on 2.3 block

Mark_88 · Feb 5, 2018

Could be coming from a few places...you can get a dye to put in the fuel to see where it is leaking if you don't see obvious signs of leaks...

Is it catching when you crank it now? If so is it doing the same thing or is it not starting at all?

Johnnyboiranger22 · Feb 5, 2018

Mark_88 said:
Could be coming from a few places...you can get a dye to put in the fuel to see where it is leaking if you don't see obvious signs of leaks...

Is it catching when you crank it now? If so is it doing the same thing or is it not starting at all?

its still doing the same thing it will turn on than shudder and jump and cuts off other times it will rev to 5k and just turn off and i hear a pop sounds and smell the fumes when i come back to the engine area.

Mark_88 · Feb 5, 2018

OK, not fixed.

did you adjust the timing at all? Where you able to check the alignment of all the marks and confirm the crank was on the right mark?

The fuel smells could be just raw fuel being forced into the exhaust system because the timing is way off...

If you cannot confirm the crank position by the marking on the pulley then try setting the cam in position as required and then removing the belt from the crank and auxilliary gears. Rotate the crank 1/2 turn so that the #1 piston is at TDC and then install the belt without moving the cam.

Make sure the aux gear is aligned to the diamond as indicated in the video and then try starting again.

If you've already done that then it might be something else is off...like firing order on the coil pack.

Johnnyboiranger22 · Feb 5, 2018

Mark_88 said:
OK, not fixed.

did you adjust the timing at all? Where you able to check the alignment of all the marks and confirm the crank was on the right mark?

The fuel smells could be just raw fuel being forced into the exhaust system because the timing is way off...

If you cannot confirm the crank position by the marking on the pulley then try setting the cam in position as required and then removing the belt from the crank and auxilliary gears. Rotate the crank 1/2 turn so that the #1 piston is at TDC and then install the belt without moving the cam.

Make sure the aux gear is aligned to the diamond as indicated in the video and then try starting again.

If you've already done that then it might be something else is off...like firing order on the coil pack.

Tried it again no luck this time it kept revving to 4-5k and shuts off, im pretty sure im not timing this thing right, its confusing me so bad i know how to do the cam timing and oil pump, but thats it, i think its time to bow down and have a mobile mechanic or shop finish the rest because i dont want to dmg the engine trying this over and over. Im going go try one more time and check coil packs.

Mark_88 · Feb 5, 2018

It there is someone who can have a look at it that might be better than beating yourself up or letting the engine rattle itself to an early demise. They are pretty tough engines though and I'd have to admit to trying my best to destroy mine with little success...

Definitely go over the coil packs again...especially the lower one that feeds the exhaust side since that is the one that matters...the intake side is the waste spark system and it doesn't actually kick in until the engine is running.

Johnnyboiranger22 · Feb 5, 2018

Mark_88 said:
It there is someone who can have a look at it that might be better than beating yourself up or letting the engine rattle itself to an early demise. They are pretty tough engines though and I'd have to admit to trying my best to destroy mine with little success...

Definitely go over the coil packs again...especially the lower one that feeds the exhaust side since that is the one that matters...the intake side is the waste spark system and it doesn't actually kick in until the engine is running.

I will defiantly try this tomorow, could the coil pack be the issue to why it does that? also is there anyway possible that the crankshaft pulley marking could be off and not the same as the marking on the crankshaft itself?

Mark_88 · Feb 5, 2018

The keyway ensures that the pulley is installed in a fixed position. I was trying to see if the keyway in any way lined up with the marking on the crankshaft but I couldn't tell from the video. The keyway uses a metal chip (woodrufk key) to keep the gear in place. Sometimes the key breaks or falls out and causes the gear go slip...if that happens you can never set the timing...

But aside from that...if you can determine where the keyway is relative to the mark on the crankshaft pulley...you'd know for sure where the TDC should be...

Otherwise...there are only two positions for the piston to be at TDC...one is right and the other is wrong. So, what I was suggesting before was to line up your marks with the belt on, make sure you are at TDC...remove the belt and roll the CRANKSHAFT to hit the other TDC position with piston #1 and install the belt again.

Before you do that though use something like a coloured marker (pink nail polish for example) to mark where the crank is now...that way there will be no doubt and you can narrow down your odds of getting it right to 1 in 2.

Try that...it might work...but definitely check the coil pack firing order before you do anything else...you would not be the first person to mix it up and the engine may start but it can't run smoothly or at all if the order is off...

You should be getting backfire or some other symptoms in various configurations of firing order being wrong...most common is to mix up plugs 1 and 2...so you are firing basically 2431 instead of 1342...and it may start but cannot run at all...

That's just an example...so check it with a diagram like the one below...

https://www.autozone.com/repairguides/Mazda-B-Series-1998-06/Firing-Orders/Firing-Orders/_/P-0996b43f80377488

There are several on this page...the second last shows the config for your engine...take a picture of it or print it off and put it in a plastic sleeve for future use... :icon_thumby:

Johnnyboiranger22 · Feb 5, 2018

Mark_88 said:
The keyway ensures that the pulley is installed in a fixed position. I was trying to see if the keyway in any way lined up with the marking on the crankshaft but I couldn't tell from the video. The keyway uses a metal chip (woodrufk key) to keep the gear in place. Sometimes the key breaks or falls out and causes the gear go slip...if that happens you can never set the timing...

But aside from that...if you can determine where the keyway is relative to the mark on the crankshaft pulley...you'd know for sure where the TDC should be...

Otherwise...there are only two positions for the piston to be at TDC...one is right and the other is wrong. So, what I was suggesting before was to line up your marks with the belt on, make sure you are at TDC...remove the belt and roll the CRANKSHAFT to hit the other TDC position with piston #1 and install the belt again.

Before you do that though use something like a coloured marker (pink nail polish for example) to mark where the crank is now...that way there will be no doubt and you can narrow down your odds of getting it right to 1 in 2.

Try that...it might work...but definitely check the coil pack firing order before you do anything else...you would not be the first person to mix it up and the engine may start but it can't run smoothly or at all if the order is off...

You should be getting backfire or some other symptoms in various configurations of firing order being wrong...most common is to mix up plugs 1 and 2...so you are firing basically 2431 instead of 1342...and it may start but cannot run at all...

That's just an example...so check it with a diagram like the one below...

https://www.autozone.com/repairguides/Mazda-B-Series-1998-06/Firing-Orders/Firing-Orders/_/P-0996b43f80377488

There are several on this page...the second last shows the config for your engine...take a picture of it or print it off and put it in a plastic sleeve for future use...

I read the diagram so i think i may have them correct so spark plugs are 1234 putting in so i might be stupid for asking this do do 1342 so do i hook up the second spark plug on 3 and 3rd spark pluf on 4 and last on 2? Or now?

Mark_88 · Feb 5, 2018

It's easy to confuse this...as the diagram shows the front of the engine is where #1 plug is...so take the wire from the first plug on the exhaust side and plug it into the rear coil pack where the number one is in the diagram. That should be the shortest plug wire in the set. Then do the same all along on the exhaust side only.

Don't even worry about the intake side plugs...they do not fire when the engine is starting...

If you just focus on that part of it you can't go wrong. They may be correct...that means the timing belt could be set wrong or the SPOUT was not removed to set the base timing.

If none of that helps...you may need to seek professional help...lol

Johnnyboiranger22 · Mar 18, 2018

Mark_88 said:
It's easy to confuse this...as the diagram shows the front of the engine is where #1 plug is...so take the wire from the first plug on the exhaust side and plug it into the rear coil pack where the number one is in the diagram. That should be the shortest plug wire in the set. Then do the same all along on the exhaust side only.

Don't even worry about the intake side plugs...they do not fire when the engine is starting...

If you just focus on that part of it you can't go wrong. They may be correct...that means the timing belt could be set wrong or the SPOUT was not removed to set the base timing.

If none of that helps...you may need to seek professional help...lol

Sorry for the huge delay i havent been able to work on it job has been to demanding, but I've seek professional help and he couldn't get it started either ot would do the same rev shut up and a nasty knocking noise so he pin pointed back to the cylinder head again because he said he couldnt find any vacuum leaks i however did notice today when i tool it all back apart i forgot to plug in the oil and coolant pressure swirches. But i dont think those would cause it, however i put the 2.5 head down and played with it it looks like nothing is wrong externally but i did notice oil in the 3rd hole on the engine block, what else could it be before i order a 300dollar remanufactured cylinder head?

tomw · Mar 19, 2018

100 posts, and I cannot tell what is going on .... I've read them all, but there are so many it's easy to lose track.
From what I gather:
the engine starts(or not???) and revs to 5k.
If not, go back to where it did start. You have a couple cylinder heads, maybe one installed and maybe one or two on the shop floor. I dunno.
The 8 plug head will work on any 2.3 if you have an intake that will match the ports, and develop vacuum(sealed to atmosphere even though there are OTHER ports left open).
You only need the exhaust side plugs to work.
The Advance site shows two coil setups for distributorless ignition. Make sure which one you have when installing plugs. The 2.3 system has the plug wires in different spots on the coil than the 8 plug coil(main - exhaust side) which are the ones that get it started and running.
If your engine starts and revs, you have the throttle plate wide open or at least partially open. Your system may have a fail-safe shutdown mechanism that cuts the ignition or fuel when the revs get too high in neutral. I know some do. Get the revs under control, make sure the throttle plate is closed and there are no other intake leaks. If you can't get it started, check the intake for failure to seal, as that would cause uncontrolled engine speed...
tom

p.s. I think a summary of the current status might help in figuring out what's wrong.

Johnnyboiranger22 · Mar 20, 2018

tomw said:
100 posts, and I cannot tell what is going on .... I've read them all, but there are so many it's easy to lose track.
From what I gather:
the engine starts(or not???) and revs to 5k.
If not, go back to where it did start. You have a couple cylinder heads, maybe one installed and maybe one or two on the shop floor. I dunno.
The 8 plug head will work on any 2.3 if you have an intake that will match the ports, and develop vacuum(sealed to atmosphere even though there are OTHER ports left open).
You only need the exhaust side plugs to work.
The Advance site shows two coil setups for distributorless ignition. Make sure which one you have when installing plugs. The 2.3 system has the plug wires in different spots on the coil than the 8 plug coil(main - exhaust side) which are the ones that get it started and running.
If your engine starts and revs, you have the throttle plate wide open or at least partially open. Your system may have a fail-safe shutdown mechanism that cuts the ignition or fuel when the revs get too high in neutral. I know some do. Get the revs under control, make sure the throttle plate is closed and there are no other intake leaks. If you can't get it started, check the intake for failure to seal, as that would cause uncontrolled engine speed...
tom

p.s. I think a summary of the current status might help in figuring out what's wrong.[

Apologize for the confusion, basically lets give you a quick insight. I've installed a 2.5 head on the 2.3 block and got everything put back together and started the truck, the truck will rev to 5k sometimes and shut right off, to keep it running you have to keep spraying starting fluid in and it doesn't sound good running either, it ran before i did this just needed a new cylinder head gasket, so i had a professional come out to look it over and he put it back on the cylinder head because it made a knocking noise and i did'nt have it tested (stupid on me) and everything else is right, so i'm back at square one and was just gonna buy a re manufactured cylinder head and be done but i want to make sure it isn't anything else that could cause that before i drop coins on that head. I've attached a video for reference as how it sounded with the 2.5 head. https://youtu.be/Tw5P3O_Jq9I

2.5 head on 2.3 block

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