Blacktop detonating...

[alamo]

I'm running a Blacktop in an AE101 FXGT. It's had a recent engine rebuild and as far as I know it's completely standard with just some new rings, bearings, pod filter and cat taken out of the exhaust.

I was going through the desert road the other day and it started detonating near the highest, winedy part of the road. I couldn't accelerate and had to cruse for 5 min until I came down the other side and it started going hard again.

It's only done this once on another occasion very briefly when I was driving it hard on a hot day around some sharp corners in the Waikato.

Does anyone have any ideas about what to do to find the problem? At this stage I’m thinking maybe the silvertop (standard FXGT) fuel pump is not keeping up? Or maybe the fuel filter, but that looks to have been changed by the previous owner.

Or maybe it’s just the very hot temperatures at the moment causing detonation? It does still have the standard leads but wouldn't they cause it to miss fire around town and stuff as well?

[Crampy]

I'm running a Blacktop in an AE101 FXGT. It's had a recent engine rebuild and as far as I know it's completely standard with just some new rings, bearings, pod filter and cat taken out of the exhaust.

I was going through the desert road the other day and it started detonating near the highest, winedy part of the road. I couldn't accelerate and had to cruse for 5 min until I came down the other side and it started going hard again.

It's only done this once on another occasion very briefly when I was driving it hard on a hot day around some sharp corners in the Waikato.

Does anyone have any ideas about what to do to find the problem? At this stage I’m thinking maybe the silvertop (standard FXGT) fuel pump is not keeping up? Or maybe the fuel filter, but that looks to have been changed by the previous owner.

Or maybe it’s just the very hot temperatures at the moment causing detonation? It does still have the standard leads but wouldn't they cause it to miss fire around town and stuff as well?

Is the pod filter just sitting off a pipe, or is inside a good cold air feed? That oculd be part of the problem. Sucking in hot air from the engine bay will not go well with that motor. Also, do you have the factory air temp snesor plugged in and in the direct airstream?

[alamo]

Is the pod filter just sitting off a pipe, or is inside a good cold air feed? That oculd be part of the problem. Sucking in hot air from the engine bay will not go well with that motor. Also, do you have the factory air temp snesor plugged in and in the direct airstream?

Yeah it's just a pod filter off a pipe and I can't see the air temp sensor. I didn't do the conversion so not sure what they did there... where is it suposed to wire into? I might have to sort that out soon.

[Crampy]

Is the pod filter just sitting off a pipe, or is inside a good cold air feed? That oculd be part of the problem. Sucking in hot air from the engine bay will not go well with that motor. Also, do you have the factory air temp snesor plugged in and in the direct airstream?

Yeah it's just a pod filter off a pipe and I can't see the air temp sensor. I didn't do the conversion so not sure what they did there... where is it suposed to wire into? I might have to sort that out soon.

the factory air temp has a two wire plug, and it sits inside the stock air box where the filter is. A lot of people just sit it inside the engine bay when they put a pod and pipe on the intake. Big no no. The engine needs to know what temp the incoming air is.

[alamo]

the factory air temp has a two wire plug, and it sits inside the stock air box where the filter is. A lot of people just sit it inside the engine bay when they put a pod and pipe on the intake. Big no no. The engine needs to know what temp the incoming air is.

When they bought the engine (off a wreaker I think) would the air temp sensor have been part of the purchase? Because it think they just used the silvertop loom... does the silvertop setup have a temp sensor compatible with the blacktop engine?

[Crampy]

the factory air temp has a two wire plug, and it sits inside the stock air box where the filter is. A lot of people just sit it inside the engine bay when they put a pod and pipe on the intake. Big no no. The engine needs to know what temp the incoming air is.

When they bought the engine (off a wreaker I think) would the air temp sensor have been part of the purchase? Because it think they just used the silvertop loom... does the silvertop setup have a temp sensor compatible with the blacktop engine?

It should have been. I got my Blacktop with the entire air intake, loom computer, the lot.
Depends what they include in the package.
A lot of wreckers will just have a cut loom, as the motor is normally to replace the same type.

[Crampy]

The Silvertop doesn't have a separate air temp from memory. I think there's something incorporated in the AFM, but will need to have that confirmed.

[QikStarlie]

how do you know its detonating? what does it do when it does it?

[alamo]

Thanks for the help Crampy.

If I get a blacktop air temp sensor does anyone know where to wire it into on a sliver top loom?

[alamo]

how do you know its detonating? what does it do when it does it?

When it did it in the Waikato it was one big miss fire but on the desert road it was like lots of tiny little misfires that make a pinging noise and I couln't use more than 1/4 throttle.

[Bling]

What gear, speed, revs would this happen at?

Doesn't have to be exact i'm just wondering.

[Crampy]

Thanks for the help Crampy.

If I get a blacktop air temp sensor does anyone know where to wire it into on a sliver top loom?

Silvertop loom? Are you running a MAP sensor or the Silvertop AFM?

[alamo]

Thanks for the help Crampy.

If I get a blacktop air temp sensor does anyone know where to wire it into on a sliver top loom?

Silvertop loom? Are you running a MAP sensor or the Silvertop AFM?

Well It hasn't got an airflow meter so must be map sensor.

[alamo]

What gear, speed, revs would this happen at?

Doesn't have to be exact i'm just wondering.

All gears except 5th and only when the reves get to about 4k but it depends on throttle position as well. At the highest point on the desert road it wouldn't rev over 4 and had no power.

[alamo]

So they would have had to use a blacktop loom then because of the map sensor?

[Bling]

Something is not right there at all. You shouldn't be losing power.

Have they used a silvertop loom and ECU as well?

Can you take a photo of your engine bay by chance? Could shed some light as to how the intake is setup etc.

[alamo]

Something is not right there at all. You shouldn't be losing power.

Have they used a silvertop loom and ECU as well?

Can you take a photo of your engine bay by chance? Could shed some light as to how the intake is setup etc.

When I bought it I had to rebuild the engine. We found the timing out, wrong spark plugs, an ecu out of a 98 corrolla , white spark plugs and an exhaust leak on cylinder 3 (low compression).

So since then it's had done:

New head
Rings and bearings
Blacktop ecu
Iridium sparkplugs
Correct timing
Reconditioned VVT unit and new seals

It goes very well 98% of the time it's just the detonation problem to sort out now. How could I tell if it running the correct loom? My feeling is that Crampy is right. It's the pod filter and lack of air temp sensor thats the problem.

[neo]

+10 Points for a blacktop in a 101FX
-5 Points for the air intake
-3 Points for the PCV valve still being plumbed into the inlet runners for the return.

[alamo]

+10 Points for a blacktop in a 101FX
-5 Points for the air intake
-3 Points for the PCV valve still being plumbed into the inlet runners for the return.

Cheers, but what do you mean by the last point?

[alamo]

The Silvertop doesn't have a separate air temp from memory. I think there's something incorporated in the AFM, but will need to have that confirmed.

Can someone confirm this? If I get a blacktop air temp sensor where do I wire it into on the loom?

Also I'm thinking about getting a standard blacktop or silvertop air box becasue that pod filter is just horrible sitting there.