P38A Slow to rev, down on power

Bix · 2024-12-20T11:10:06+0000

Howdy, hoping for someone with more ideas than I do has some clues.
FIP was replaced in October, failed November. Finally got her back with a new FIP on Wednesday. Guy said she is down on power, but after the last one died was hesitant to chase any.
Fair enough, don't want to dump gallons of fuel on floor again. Was fine if a little slow driving home. Happy days.

Yesterday went to head into town, refuses to build Boost. Unplugged MAF, nothing. Limped home and had a look, turns out the Boost control solenoid was unplugged and had detached from the firewall (the brackets it bolts to are only glued on it seems). Plugged it back in, cable tied into place, was back to how it was Wednesday. Happy days went about my day.

Today went to head into town again, nothing. Doesn't rev past idle in gear so couldn't even leave the parking spot, let alone the street. Had another look, everything was still where it should be, double weird.

Wife came out and asked me what I'd have done if a customer car came in no power, made me think of a Landy came in with similar symptoms, that was the EGR stuck open flooding the engine with exhaust. So I unplugged the vacuum hose and blocked it off which gave me back some power, not quite what it was like Wednesday, but not far off.

In my head the EGR is suspect, possibly stuck open, but without the vacuum it should be closed so I'll try the coin trick to block it and see if that helps.
But is it possible the boost solenoid was damaged when it detached from the firewall and started bouncing around and possibly needs replacing too?

Thanks.

Datatek · 2024-12-20T16:58:23+0000

Bix said:
Howdy, hoping for someone with more ideas than I do has some clues.
FIP was replaced in October, failed November. Finally got her back with a new FIP on Wednesday. Guy said she is down on power, but after the last one died was hesitant to chase any.
Fair enough, don't want to dump gallons of fuel on floor again. Was fine if a little slow driving home. Happy days.

Yesterday went to head into town, refuses to build Boost. Unplugged MAF, nothing. Limped home and had a look, turns out the Boost control solenoid was unplugged and had detached from the firewall (the brackets it bolts to are only glued on it seems). Plugged it back in, cable tied into place, was back to how it was Wednesday. Happy days went about my day.

Today went to head into town again, nothing. Doesn't rev past idle in gear so couldn't even leave the parking spot, let alone the street. Had another look, everything was still where it should be, double weird.

Wife came out and asked me what I'd have done if a customer car came in no power, made me think of a Landy came in with similar symptoms, that was the EGR stuck open flooding the engine with exhaust. So I unplugged the vacuum hose and blocked it off which gave me back some power, not quite what it was like Wednesday, but not far off.

In my head the EGR is suspect, possibly stuck open, but without the vacuum it should be closed so I'll try the coin trick to block it and see if that helps.
But is it possible the boost solenoid was damaged when it detached from the firewall and started bouncing around and possibly needs replacing too?

Thanks.

What car is this? If a P38, the EGR valve can certainly stick open. I run mine with the vacuum tube disconnected and blocked with an M5 screw except when they go for the MOT.
Boost solenoid on the bulkhead? What's that and where precisely?

Bix · 2024-12-20T17:28:07+0000

Datatek said:
What car is this? If a P38, the EGR valve can certainly stick open. I run mine with the vacuum tube disconnected and blocked with an M5 screw except when they go for the MOT.
Boost solenoid on the bulkhead? What's that and where precisely?

Yes, 2.5 P38.
I was pondering the possibility of it sticking open without the vacuum line disconnected.

It sits behind the EAS compressor against the bulk head. One of the outlets goes to the EGR, one has an air filter on it, the other I haven't worked out where it goes to yet.

Datatek · 2024-12-20T17:31:06+0000

Bix said:
Yes, 2.5 P38.
I was pondering the possibility of it sticking open without the vacuum line disconnected.

It sits behind the EAS compressor against the bulk head. One of the outlets goes to the EGR, one has an air filter on it, the other I haven't worked out where it goes to yet.
View attachment 332062

That is not a boost solenoid, the the control valve for the EGR. The other pipe goes to the vacuum pump on the front of the cam cover. The EGR valve can certainly get coked up and stick.

Bix · 2024-12-20T17:48:09+0000

Datatek said:
That is not a boost solenoid, the the control valve for the EGR. The other pipe goes to the vacuum pump on the front of the cam cover. The EGR valve can certainly get coked up and stick.

That was my understanding, but everywhere I've looked has it as a boost control solenoid. Guess it's the same thing just used differently?
I've have a further investigation tomorrow when the rain stops.

Datatek · 2024-12-20T17:49:37+0000

Bix said:
That was my understanding, but everywhere I've looked has it as a boost control solenoid. Guess it's the same thing just used differently?
I've have a further investigation tomorrow when the rain stops.

The photo you posted is too small to see clearly but it does not look like the correct item.

Bix · 2024-12-20T17:54:30+0000

Datatek said:
The photo you posted is too small to see clearly but it does not look like the correct item.

This is the offender. The studs it attaches to are only glued to the bulk head and they had separated ways, some how the plug in it had become detached. I tried to cable tie it back in place, not pretty but is holding for now.

Datatek · 2024-12-20T17:58:21+0000

Bix said:
This is the offender. The studs it attaches to are only glued to the bulk head and they had separated ways, some how the plug in it had become detached. I tried to cable tie it back in place, not pretty but is holding for now.

View attachment 332064

Yes, that's the one for the EGR. The studs were welded to the bulkhead, looks like they may have rusted off from your photo.
Except for the MOT, you do not need it, leave the pipe off the EGR valve at the manifold and block the end of the rubber pipe with an M5 screw. Worth taking the EGR valve off and giving it a good decoke then there is no need to block anything as with the pipe off the valve will stay closed.

P38A Slow to rev, down on power

Bix

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Datatek

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Bix

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Datatek

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Bix

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Bix

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Datatek

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