Ruff Idle ,Huge Loss of Power

[dredgeguy]

Sure thing but sometimes dreams can turn into nightmares. Have a few stories to tell you at Carlisle. Flying down the middle of the Straits of Hormuz and cutting east over Iran in a 777 when missiles are in the air will keep the pucker factor very high!

[Tripler]

Originally Posted by dredgeguy

Sure thing but sometimes dreams can turn into nightmares. Have a few stories to tell you at Carlisle. Flying down the middle of the Straits of Hormuz and cutting east over Iran in a 777 when missiles are in the air will keep the pucker factor very high!

YIKES ! I would use another word than pucker but then I would get banned from the site lol !



Stay safe ...
Mike

[Tripler]

Originally Posted by secondchance

A small hard black hose was not attached to a softer rubber 90 elbow. Is that the MAP Sensor ?

Was this hose between the back of the plenum to underside of MAP sensor? MAP sensor is under an aluminum trim behind the plenum. Once reconnected, all should return to normal. If not, I suspect something else blew off under the plenum on top of MAP sensor hose when it backfired.

Yes it was . I am going to put a plastic ty on it to squeeze it tighter . Could not drive it today . Movie shoot on our street took up all our car moving spots and a bit of rain .

Started it and it sounded better but not a smooth as it used to be .

Thanks for the tips

Mike

[Tripler]

Drove it around the block . Feels like a 6 or 4 and is still running ruff . Bought a video scope to look under the plenum .
Also on another note , the car only backfired 3 or 4 times since we have owned it since 2016 and it would only do it going down a hill with my foot off the gas pedal in second gear, just a small pop but it did not always happen . Just once in a blue moon .
Mike

Sent from my ASUS_X00PD using Tapatalk

[secondchance]

Originally Posted by Tripler

Drove it around the block . Feels like a 6 or 4 and is still running ruff . Bought a video scope to look under the plenum .
Also on another note , the car only backfired 3 or 4 times since we have owned it since 2016 and it would only do it going down a hill with my foot off the gas pedal in second gear, just a small pop but it did not always happen . Just once in a blue moon .
Mike

Sent from my ASUS_X00PD using Tapatalk

If you hear a pop going down hill with foot off, my guess is unburned fuel mixture going downstream and lighting up. This should not cause MAP blow-off. MAP sensor hose blows off when you back fire during the engine start.

Again, it's just a WAG - if MAP hose is intact and still suffering from misfire, either a fuel system issue (like fuel pump, clogged fuel filter, etc.) or a vacuum blown under the plenum.
I presume CEL is not on? Can you see if you can jump OBD and pull code?

[Paul Workman]

If that MAP hose(s) were disconnected and now restored, I'd wanna pull and inspect the plugs. Could be some plug(s) got fouled and will run OK when they are cleaned up.

Experience is generally a good thing when troubleshooting; it can lead one to the issue sometimes immediately. But! If guessing at the solution proves not to be the case (fix), it"s back to the basics time!

FUEL PRESSURE (static) = ?
Current draw on the pump diagnostic test point (red wire about 5cm long w/ a black terminal sticking out of the large wire loom near the W/S wiper motor) when ignition key is in the OFF position [8-10 amperes is normal for both pumps running nornally].

Let us know what U find...

[Paul Workman]

Next:

When you shut off the ignition switch, does fuel pressure hold to within a pound or two for 10-15+ minutes, or drop to zero briskly?

[Tripler]

Originally Posted by secondchance

If you hear a pop going down hill with foot off, my guess is unburned fuel mixture going downstream and lighting up. This should not cause MAP blow-off. MAP sensor hose blows off when you back fire during the engine start.

Again, it's just a WAG - if MAP hose is intact and still suffering from misfire, either a fuel system issue (like fuel pump, clogged fuel filter, etc.) or a vacuum blown under the plenum.
I presume CEL is not on? Can you see if you can jump OBD and pull code?

Yes . My first thought also . ordered a new fuel filter . Will be changing that first and go from there .

I am not sure how to jump OBD to see if there is a code . Sorry .


Thanks for the tip .

Mike

[Tripler]

Originally Posted by Paul Workman

If that MAP hose(s) were disconnected and now restored, I'd wanna pull and inspect the plugs. Could be some plug(s) got fouled and will run OK when they are cleaned up.

Experience is generally a good thing when troubleshooting; it can lead one to the issue sometimes immediately. But! If guessing at the solution proves not to be the case (fix), it"s back to the basics time!

FUEL PRESSURE (static) = ?
Current draw on the pump diagnostic test point (red wire about 5cm long w/ a black terminal sticking out of the large wire loom near the W/S wiper motor) when ignition key is in the OFF position [8-10 amperes is normal for both pumps running nornally].

Let us know what U find...

Yes . Will be pulling the plugs and let you know whats up . The way it was running I guarantee there fouled for sure . Will clean them first before fuel filter change and see if it runs smoother .

Thanks Paul .

Mike

[Tripler]

Originally Posted by Paul Workman

Next:

When you shut off the ignition switch, does fuel pressure hold to within a pound or two for 10-15+ minutes, or drop to zero briskly?

How would I check fuel pressure ? Do I need to attach a gauge somewhere along the fuel line ?



Thanks



Mike