2.8 stalls under load?

[60dgrzbelow0]

Wow, look at my mad typin skills, yo! I typed rong instead of ring... And I usually read over stuff before I post it...

...that little "Edit" button that only appears in the lower right hand corner of the text box when you're logged on ...is a very handy gizmo for fixing those little "finger eff-ups".

[CNCguy]

Bimdub.... The ECM has to know the RPM to be able to calculate how often and how much to fire the injectors. Without an RPM signal, the ECM sees the engine as not running and will not fire the injectors.

A basic explanation of how this system works is: The ICM gets a signal from the CPS to know which coil to fire and where the base timing location is. It constantly outputs a signal to the ECM which is used with data from other sensors to calculate injector pulse width and ignition timing. The ECM fires the injectors as needed and also sends a signal back to the ICM to advance/retard timing.

A Tach would not give you the info you need since the tach is driven via a separate output from the ICM. Hence the reason for suggesting a scanner/ALDL logging as it would display what the ECM sees the RPMs at.

The ALDL cable only uses two wires to transfer data in serial format to the scanner/laptop. With these two wires, you can monitor well over fifty items of information (such as speed, rpm, MAP, TPS, Inj PW, timing, volts, O2 sensor, error codes, etc) ten times per second.

I, too, lean towards it being the ICM and would swap it for another to verify. But I have several here and it wouldn't cost anything to try. Do you know someone that would let you borrow their ICM for a few minutes. Pretty much any from the late '80s to early '00s FWD 2.8L, 3.1L, 3100 or 3400 should work.

[60dgrzbelow0]

There is no DIS lobe on the crank. The ICM and ECM both get their signal for the crank position from the CPS. There will be a twisted wire going from it to the ICM, then the ICM "forwards" this signal to the ECM while using it for the spark events. It couldn't hurt to replace the CPS, I don't think they are expensive. If you decide to, its on the rear of the engine, towards the center (when looking from side to side) probably about 2-3 inches above the oil pan. The connector will be a 2 prong, and the plug on the CPS should be at a 90 degree angle. I was always under the impression that CPS either worked or didn't work, though.

Wasn't there a post or two about some members discovering that if this "Twisted Wire" is altered either by the addition of turns ... or by being accidentally unraveled to some degree...that the ICM will cease to function correctly?... Or is my Logic "twisted" once again?

[pocket-rocket]

You would have to untwist it to do any harm. It's twisted like computer network cable (Cat5, ect) for the same reason. The twists help it reject outside interference. As for the edit button, I tend to not edit posts if someone else has posted after me so it doesn't look like I am trying to cover up a stupid mistake on my part. I'm not a shady person, nor do I want to come off as one.

[60dgrzbelow0]

Oh...right... CAT-5E (four pair twisted (white orange- orange, white green-blue, white blue-green, white brown-brown) Now that counter-interference "twisting" idea makes sense...

Sorry about that "Edit" Button reference... I was only suggesting that its use was more like an eraser on a pencil than as a means to change the content of your post. I can't imagine anyone who knows the value of your conduct and contributions in here ever losing their good opinions about you ... just for the sake of your fixing an occasional typo error. I have to rely on the feature a great deal to correct my mistakes and get things right.

[bimdub]

given that the Ignition is still delivering the spark.....I would think the CPS is fine....

[pocket-rocket]

I didn't take offense to the edit comment at all.

I think you would be correct, bimdub.

[bimdub]

I am just goint to go ahead and shove a new ICM in there...if it does not solve the problem.....at least I will have a spare for use later in life......who knows.....

[pocket-rocket]

Spare parts that are known to go out isn't really a bad thing to have. I have a DOHC alternator on the shelf...

[60dgrzbelow0]

I didn't take offense to the edit comment at all. ... I think you would be correct, bimdub.

(Whew...Okeedoke... )



I was wondering...if this solution is not found in the electronic sensor failures/reading side...what are the chances there is an (U/L) IM vacuum leak somewhere that only presents itself at 2,000 RPM or better? How would you nab that symptom with the engine approaching two grand?

[robertisaar]

I am just goint to go ahead and shove a new ICM in there...if it does not solve the problem.....at least I will have a spare for use later in life......who knows.....

if you grab a known good coil as well, you can make an interesting spark plug tester...

[bimdub]

I am seeing good vacuum with my gauge.....the needle is steady and around 20+ inches

[bimdub]

if you grab a known good coil as well, you can make an interesting spark plug tester...

I have a motorcycle coil I use for testing plugs....its small....and triggers from a 9volt and a momentary switch....

[60dgrzbelow0]

Sherlock Holmes famously said, "When you've eliminated everything that is reasonably possible... whatever is left, however illogical it may seem...is the answer to any problem..."

What else can be looked at that you have not already done?

[robertisaar]

Sherlock Holmes famously said, "When you've eliminated everything that is reasonably possible... whatever is left, however illogical it may seem...is the answer to any problem..."

AWESOME.