87 240 B230F power loss glowing red manifold

overgreg · Post by **overgreg** » 23 Dec 2010, 09:33

Hi All,

I'm looking for help regarding wife's 87 240 wagon with b230f engine, auto tranny. The car runs great (325k miles), but lately has been losing power drastically after hard right turns like freeway circle ramp etc. Seems like that's when it happened each time it happened, but not every time you took a hard right turn, inconsistent.
A couple of weeks ago I found the no. 1 plug wire arcing, so she got a new set of OEM wires, cap and rotor, thought I was a smart guy. But last night I was driving and it happened again. Here's how I would describe it: Sudden power loss, some backfiring Pop-pop once or twice when I pressed the accelerator, sounds like from the intake perhaps, muffled and not from the tailpipe, definitely under the hood.
Car runs as though the timing is really off. When I opened the hood to see if a plug wire had come off or something, I saw a glowing red manifold. Looked around, found no wires had come off etc, dist cap was on properly and all. Started up, ran like a champ almost for the 15 miles or so home, then happened again just blocks away, this time while pulling away from a stop light (no right turn involved). I pulled into a parking lot, shut it off, then started back up immediately and it ran great the rest of the drive.
So I think it's an electrical issue perhaps? I've done some research here and the knock sensor seems a candidate. But I'm looking for help before I start ham fisting around under the hood.

Thanks!
Greg in Denver

Post by **billofdurham** » 23 Dec 2010, 11:48

My immediate thought was a bad in-tank fuel pump. Stalling during turns is usually indicative of such a problem. Does it happen when you have a full tank of petrol, or only when you're down to 1/3 tank or less? The main pump can cope without the in-tank pump whilst the fuel level is relatively high although it will be noisier as it works harder. You can check the in-tank pump is working by removing the filler cap and listening at the filler opening for a buzzing sound.

In most unmodified car engines it is not normal to see the exhaust manifold glow red. However, if modifications have been done to the engine then it is not uncommon to see the exhaust manifold glow red. This occurs when the ignition timing and fuel mixture are changed causing an excessive amount of heat. Enough heat to make the exhaust manifold glow red. If your in-tank pump has failed the computer could be compensating by changing the timing.

Bill.

overgreg · Post by **overgreg** » 23 Dec 2010, 12:39

Thanks Bill. I hadn't checked the level in the tank on previous happenings, but did check the in-tank pump as one of my first suspects. It seems to be working fine. And this latest occurrence was not long after a fill up, with the fuel gauge still showing Full.
When this issue is not present, the car runs strong and never seems to have a fuel starvation problem. I was wondering about the fuel pump relay, having heard that they are problematic, but would that be sporadic like this?

Thanks!

Greg

Retired MVS Contributor · Post by **Retired MVS Contributor** » 23 Dec 2010, 12:45

My guess is a restricted catalytic converter...When the matrix breaks up the pieces move around and clog the outlet, backing pressure up into the exhaust manifold...If you rap on the converter with your fist and hear rattling inside, the converter is gone...

overgreg · Post by **overgreg** » 23 Dec 2010, 12:54

Thank you Jerry. Well, that's another issue. This car has had the cat removed some years ago. It came from a location that did not have emissions testing, and at some point the cat was probably bad and was removed and replaced with a new straight pipe section between downpipe and muffler sections.
I will need to put a cat in as we now live in an emissions testing area, but it's run wonderfully for five or six years without it.

G

Kmaniac in California USA · Post by **Kmaniac in California USA** » 23 Dec 2010, 14:12

jerrymcc wrote:My guess is a restricted catalytic converter...When the matrix breaks up the pieces move around and clog the outlet, backing pressure up into the exhaust manifold...If you rap on the converter with your fist and hear rattling inside, the converter is gone...

overgreg wrote:Thank you Jerry. Well, that's another issue. This car has had the cat removed some years ago. It came from a location that did not have emissions testing, and at some point the cat was probably bad and was removed and replaced with a new straight pipe section between downpipe and muffler sections.

To expand upon Jerry's comment and yours, this could be a restriction in the muffler from baffles that have rotted and floating around inside.

overgreg · Post by **overgreg** » 23 Dec 2010, 15:08

Thanks Chris. I was just able to go in the garage and knock the muffler and tailpipes around, but got no rattling or any other sound out of them. Would a clog like that be something that would happen only occasionally? Would it get worse with time? Would the car's exhaust note get louder? She's a silky smooth and quiet runner - except when the problem occurs.

Thanks!

now let's talk about these 5(?) Chrysler 300's...want to trade one for a usually great running 87 240 wagon?

Post by **precopster** » 23 Dec 2010, 18:58

This is just heresay but there was a rumour circulating that there was a limited production run of 240s that were earmarked for Santa's sleigh. Exhaust manifolds were stamped "RUDOLPH" Unfortunately they only ran well in icy conditions and were sent to Canada LOL

HAVE A HAPPY CHRISTMAS AND GOOD LUCK WITH THE PROBLEM

Post by **jimmy57** » 23 Dec 2010, 20:58

The knock sensor or its wiring has a problem. When the ignition CM detects a fault it reverts to a very safe amount of timing advance and on the turbo motors this late ignition allows a WHOLE lot of combustion to still be taking place when exhaust valves open and the manifold and turbo glowing red hot is the product of this. The ignition CM on the 84 1/2 through 89 turbos loses its fault memory when ignition is turned off and to get the knock sensor problem to be detected you must have a high load value and over 2700 rpm so you turn off key, re-start and all is good until the fault is detected again.
It could also be low octane fuel as excessive knock will cause a safety retard of timing too. Usually low octane fuel as cause will knock loud enough to be easily heard when you accelerate moderate to hard.

overgreg · Post by **overgreg** » 23 Dec 2010, 21:42

Thank you Jimmy.
This car is not a Turbo, but I had read similar info regarding the knock sensor causing the CM to go into limp mode, and that it does change the timing, which is the driving symptom that this car shows: very low power, puttering sound, internal backfire etc etc. It idles great and there's just a tick of normal when you first push the accelerator, but then it just bluuuuh and will barely locomote itself. I read that this knock sensor situation will allow unburned fuel into the manifold where it burns and thus the red hot mani.
Can I get an Amen?

Is the knock sensor located under the intake manifold, near the temp sending switch?

Thanks!
G