96 Ram Van NO Spark - PLEASE HELP!!!
and she cranked right up. seems to be problem solved wish u luck with yours
Amateur
Joined: Sep 2011
Posts: 43
Likes: 0
From: Weatherford TX
The PCM is the prime suspect. Because the failure is intermittent, I've been trying to induce the failure by hitting the PCM with a wooden tool handle, using reasonable force of course. So far, no luck with that. Thanks.
Amateur
Joined: Sep 2011
Posts: 43
Likes: 0
From: Weatherford TX
At the FB link, I added photos of earlier cases (Sept 3rd) where the engine started and shutdown with no appreciable spikes on CAM and CRK signls.
I believe the CRK and CAM spikes in the Sept 10th data are due to my mistake in signal routing: When I reconfigured to monitor the coil driver and injector #1 (instead of 8V and ASD as I had been doing), I didn't disconnect the 8V Return probe from the wire harness. Now, the coil driver signal is routed in the same 2-conductor cable with the 8V Return line.
As far as I know now, the spikes are only artifacts seen at the scope and are not affecting the CAM and CRK signals. I imagine the PCM has some filtering that takes care of the spikes. In other words, the van would die:
(1) before I connected anything at all to it;
(2) when I monitored CAM, CRK, 8V, & ASD;
(3) and now it's dying when I monitor CAM, CRK, COIL DRIVER, and INJECTOR #1 DRIVER.
I'll verify that disconnecting the 8V Return probe lowers the magnitude of the spikes on the CAM and CRK signals when the engine is running.
I believe the CRK and CAM spikes in the Sept 10th data are due to my mistake in signal routing: When I reconfigured to monitor the coil driver and injector #1 (instead of 8V and ASD as I had been doing), I didn't disconnect the 8V Return probe from the wire harness. Now, the coil driver signal is routed in the same 2-conductor cable with the 8V Return line.
As far as I know now, the spikes are only artifacts seen at the scope and are not affecting the CAM and CRK signals. I imagine the PCM has some filtering that takes care of the spikes. In other words, the van would die:
(1) before I connected anything at all to it;
(2) when I monitored CAM, CRK, 8V, & ASD;
(3) and now it's dying when I monitor CAM, CRK, COIL DRIVER, and INJECTOR #1 DRIVER.
I'll verify that disconnecting the 8V Return probe lowers the magnitude of the spikes on the CAM and CRK signals when the engine is running.
I drove the van to a friend's shop this afternoon where we tried to induce a PCM failure by applying vibration to the PCM mounting points, the PCM connector's mounting bolt, and the firewall next to the PCM mounts using a steel rod inserted into an air tool; i.e., basically a small jackhammer. The van kept running during the vibration tests but the scope triggered so I need to look at that data.
I'm now wondering if this could be a PCM ground problem. I need to study the grounds to the PCM, especially any splices in the harnesses.
Amateur
Joined: Sep 2011
Posts: 43
Likes: 0
From: Weatherford TX
Slide Updates: The '94 Van is still running, ~4k miles later
Link to the latest version of the slides documenting my summer 2011 adventures with the '94 B350 passenger van at public facebook link:
https://www.facebook.com/media/set/?...1&l=a6d2c2ac08
Jeffrey Bledsoe, PE
https://www.facebook.com/media/set/?...1&l=a6d2c2ac08
Jeffrey Bledsoe, PE
Amateur
Joined: Sep 2011
Posts: 43
Likes: 0
From: Weatherford TX
The link I posted is truncated. Sorry.
Here's the link in quotes so this site doesn't truncate it. Copy everthing but the quotes and paste to your browser.
"https://www.facebook.com/media/set/?...1&l=a6d2c2ac08"
Here's the link in quotes so this site doesn't truncate it. Copy everthing but the quotes and paste to your browser.
"https://www.facebook.com/media/set/?...1&l=a6d2c2ac08"
Captain
Joined: Feb 2012
Posts: 515
Likes: 5
From: N. KY
I would like to check out your link, but all I get is Content unavailable error
tried both links, which appear to be the same, except for the double "
You may have to highlight from left to right the entire un-truncated link before copying and pasting.
tried both links, which appear to be the same, except for the double "
You may have to highlight from left to right the entire un-truncated link before copying and pasting.
Amateur
Joined: Sep 2011
Posts: 43
Likes: 0
From: Weatherford TX
I copied the entire link. When in quotes, the entire url was visible on the pc. Now, using my iPhone, I see that a large portion of the middle of the url is missing.
Anyway, dodgeforum.com is the source of the problem because it's altering the url.
I'll look at it again when I get back to the pc later today.
Anyway, dodgeforum.com is the source of the problem because it's altering the url.
I'll look at it again when I get back to the pc later today.
Amateur
Joined: Sep 2011
Posts: 43
Likes: 0
From: Weatherford TX
Troubleshooting 94 Dodge in 2011
Try this (used the insert link tool this time):
https://www.facebook.com/media/set/?...1&l=a6d2c2ac08
https://www.facebook.com/media/set/?...1&l=a6d2c2ac08
