• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

240 Diagnosing intermittent rhythmic power cut

This problem has me pulling my hair out. I couldn’t get it to replicate it self all weekend or yesterday, and then on the way to work it started acting up. When I got to work it was stumbling and couldn’t maintain 30mph. So I parked it and tried to test the fuel pressure. Sure enough by the time I got the guage teed in the problem went away on its own.

It absolutely seems like some component is overheating. It happened on Friday, the first day over 70 this year, and only after driving at 3000-4000 rpm for 20 minutes.
 
EivlEvo said:
Do you have a power stage to swap out? Do you have the chrysler ignition?
Click to expand...

I have two or three working power stages I could throw in there, but my car doesn?t have one. I have the Bosch 1306057 ignition control unit. I believe the ignition amplifier is integrated into that unit.
 
Fuel pump relay need a a quick resolder it sounds. Gets hot n quits. Cools down n works. If you can't solder I'll mail you one of my 25 spares...
 
satanburns1 said:
Fuel pump relay need a a quick resolder it sounds. Gets hot n quits. Cools down n works. If you can't solder I'll mail you one of my 25 spares...
Click to expand...

I reflowed the solder on this one when I first got it. Fuel pump is still running when the issue occurs.
 
I have the same symptoms on my 91 turbo 940. I have a high volume in tank pump and eliminated the in line high pressure pump. I do have old injectors, but it either runs fine or it is like a drive by wire car gets the throttle closed to idle while driving. It idles fine, it accepts throttle fine 98% of the time. And I can't get a code 1-3-3 tps idle speed to go away. I've swapped tps with a known good one. I've tested both sensors. I've checked resistance to ground and resistance from tps connector to ecm connector with no problems found. It seems like a throttle position related thing like it only happens from 20%-45% throttle opening. And most of the time I can push the pedal and it will go away, also when it happens and I come to a stop. Idle speed is about 600rpm high unless in gear, then it's like the trans is holding the idle from raising. I've added ground wire directly to battery negative post at various harness ground points with no improvement.
 
It was the coil. It was reading 2MOhms when it early stalled on me to today. Swapped in a spare and the problem went away.
 
Fake news! It stalled on me in nearly the same fashion today about 100 feet from my driveway. If this issue would exist for longer than 5 minutes at a time and was predictably reproduced, I would have solved this in less than an hour. Yet here I am, firing the parts canon with no results. I just received a fuel rail with a schradervalve from Roy today, so once I install that, I can safely go for extended drives with the fuel pressure gauge hooked up. I think I’m going to set up something to monitor a bunch of my ignition and fuel related sensors and try to replicate the problem this weekend.
 
Rig a test light to coil negative to ground and tape it by the wipers. If it stops blinking while running or trying to restart after a stall, then look towards powerstage/another component upstream in the ignition.

Do the same with another test light to the fuel pump power.

Labscope.
 
Ever since I hooked up the fuel pressure gauge and jumper wires to monitor the primary winding coil voltage the car has run like a champ without issue. I noticed that driving the car hard for about 20 minutes would make it fault considtently. Now that I’m watching it, no issues after an hour at 4K rpms.
 
Lando. I'm still in exactly the same boat as you. I swapped amms, powers ages, tps sensor, and coil, still no luck fixing or finding the problem. Mine still hasn't stalled it is fairly consistently surging under steady throttle/cutting power. I'm gonna bypass the oem fuel pump relay with a heavy gauge wire and see if it changes. I have steady voltage to the coil and the power stage. And cps is perfect when graphed on my dvom
 
Your issues sound exactly like a car I worked on a couple of years ago. Turned out to be a bad fuel filter. How old is yours?
 
Did you remove the terminals at the coil? Sometimes this scrapes of some of the fretting and the connection becomes good again.

I would lightly clean terminals and apply dielectric grease.
 
Wren said:
Your issues sound exactly like a car I worked on a couple of years ago. Turned out to be a bad fuel filter. How old is yours?
Click to expand...

I replaced it with the main fuel pump about 3 years ago. Probably worth just changing at this point. I swapped to a different fuel rail that has the schrader valve so I could monitor fuel pressure, but it hasn't acted up since then.
 
ZVOLV said:
Did you remove the terminals at the coil? Sometimes this scrapes of some of the fretting and the connection becomes good again.

I would lightly clean terminals and apply dielectric grease.
Click to expand...

Terminals are clean, but I noticed they were a tad loose when I changed the coil. I gave them a gentle squeeze with some soft jaw pliers and they are nice and snug now.
 
I don't know if this will help you, but I am fairly sure I fixed my car. After swapping ezk, and looking for bad grounds, powers, vacuum leaks etc finding nothing wrong. I checked my knock sensor and noticed one of the wires to my cold start Injector had backed out of the connector. As soon as I reinstalled the wire into the cold start Injector connector the problem stopped. I don't understand it but it stopped completely.
 
You must log in or register to reply here.
Back
Top