I actually did that today when it was acting up because I was convinced it was the C101.. I wiggled the C101 and the entire harness while it was acting up.. didn't do a thing.

 

[QUOTE=Robert88;1981164we're enjoying it. When we get this worked out we can pound our chests... that's the reward for sure.[/QUOTE]

Ha! Well...after you guys lick it, we can set up a time (PDT), and all pound our chests in unison!

(that is if Pete tells me what to tell you to make the thing work right)


U got extra c-101's cruiser, why don't you don't you send one to rob?

 

Pinch off the vacuum hose to the MAP and see if there's a change.

I'd be tempted to try tapping into the ground circuit for the MAP, TPS, IAT, and CTS and running it straight to ground instead of relying on the ECU to ground that circuit.

 

Bingo...I have had "memorable" results by clamping a long wire, (old vacuum cleaner cord once), attached right to the NEG post on the battery,,,then if you touch the other end to something that should be grounded, but isn't you know right away. . Also, find that original MAP sensor, see how that works, could learn something there.

 

So Cruiser...Are you saying all those (brown/wt), actually go through the ECU to get to ground? The thick plottens. Maybe to protect the sensor ground side? (from spikes/reverberations, maybe from stuff directly connected to the alternator and other sources of electrical mischief?)

The "Stack" (http://www.smokstak.com), has an emocon, "hammer on head"

 

 

So far, this morning: I squeezed the vacuum line to the MAP WHILE IT WAS RUNNING GOOD.. That caused it have the symptoms that I am getting when it screws up on it's own.. Also, I unplugged the IAC valve while it was running good and then while it was acting up. I am getting no change in running..From what I understand, unplugging the IAC will cause the RPM's to increase considerably? Also, I am getting 5+ V to the MAP. When I squeeze the vacuum line to the MAP while it is acting up, the symptoms get worse, to the point where it stalls.
Note: Plenty of volts to the IAC as well. I just put the old IAC back in to see what it's gunna do. It's flooded so I have to wait..

 

Yes, Don, that whole circuit grounds throught the ECU. Who knows why? Then the eCU grounds at the dipstick tube stud. I don't see an issue with grounding that circuit to the body as we.., between the sensors and the ECU. Heck, you could ground it at the diagnostic connector if need be.

I think we've eliminated the MAP based on your tests, Robert.

CTS and IAT come in next as probable culprits, in that order. Just for giggles, you could remove the IAT and clean the tip of it with throttle body cleaner. They get all carboned up.

Something I thought of this morning...A buddy of mine, a real good automotive tech, has an 88 that would intermittently "choke up" and run Rich. We hooked up my DRB and noticed that all the sensores read fine. That was until he wiggled the C101. Then the CTS signal went to crap. He bypassed the entire C101 and had no issues since.

 

I think we have a bingo.. I cleaned the IAT (which was black with carbon build up from acting up).. it helped immediately.. I let it idle for about 30 minutes, took it around the block.. it did act up when I got back but only for about 20 seconds or so and it cleared up right away.. I think we are on track..So... can a meat potato car guy like me be able to do that CTS bypass?

 

WOOF WOOF WOOF - Getting tired of barking up the WRONG TREE?

249 POSTS?

After your hour drive of course you checked the COLOR of the spark at a plug!
I know you would have IF you really are serious about solving the problem.

NO? WHY NOT?

Of course it will run terrible when you mess with things that get it too rich and foul plugs. It takes time to clear the plugs again.

Coils have a reputation for breaking down internally whenever they want - often when warm.
The color of the spark will tell you!

If the voltage is low, plugs foul, making you think it's too rich.
SEE ALL THE ABOVE POSTS TO PROVE IT!

Try this - use a heat gun - or wife's hair dryer - let it run while it's running fine - heat the coil - (explain to your "guru advisors" ignition coil, not the coil springs) watch it start running bad. Check the color of the spark at the plug then - while it's still running bad!

Coils have been breaking down since they started using the Kettering Ignition System in the 1800's.

About 1975 most vehicles stopped using oil filled coils trying to get the rise time faster with a smaller core. The oil used to help prevent internal breakdown - they "repaired themselves."
But the dry coils don't, and they tend to break down faster.

Use a scope to check it - a stock coil should put out a minimum of 28,000 volts.
No scope? Then the COLOR of the spark jumping to ground tells all you need to know. But looking at it when it's not breaking down tells you NOTHING!

WOOF WOOF WOOF!

BTW - I withdraw my offer - I bought one yesterday. $400 for a 95 no start - a shop had already charged him $600 - still wouldn't start. I put 2 gallons of gas in it and drove it home. I'll take $2500 for it.

Just because it has a computer doesn't mean it has to be complicated!
BACK TO BASICS - KISS!

 

CPS bypass is easy. And, I'd do it if it were mine. But it's not your issue.

And, that buildup is normal on an IAT just from normal wear and tear.

 

Thanks Cruiser..another piece of the puzzle! I gotta think they ran the ground through the ECU for a reason, but myself, I wouldn't mind bypassing that for diagnosis. I'm not saying I hook up my jumper cables backwards 1/2 the time...but I do. Maybe that ground like that saved my butt a couple times.

Yea Rob..my .02 there is doing a neat job of soldering one wire together is really no big deal. But what 16-20 of them? Anyway You might want a fan so as not to breath all that flux smoke. I mean if someday you have time for that.

 

I gather that unplugging the IAC motor will just leave it where it is, so you might not expect a change, (just idling). I did just read that once, but it was from a poster I tend to trust.

Here's a link on some info on bypassing the c-101 for the CPS wires. Guess if I had a c-101 I might do it just on GP, but I don't have a history of fixing things I don't think a are currently a problem!>>>
http://www.bc4x4.com/faqs/yj.cfm?cat=5&faqid=164

I'm not getting how cleaning the IAC will prevent it from duplicating having it running rich, as if the vacuum to the map were cut...but I'm learning here myself! That's awful close to that MAP tube, maybe you knocked it into shape!

So..just curious...how's it goen? Did you have an opportunity to double check that CPS output with a second digital meter? Did you mention that you might have another MAP sensor you could try if you wanted?

Anyway hope all is well, (including the Ford ball joints) .

 

Hey Don, I got a little side tracked this week, work has been murder..I'm glad I'm busy though.. I plan on getting back to it this weekend, I'll check back in.

 

IAC - IDLE AIR CONTROL
Above idle it does NOTHING. Complaint was at all speeds, not just idle.

It's like YOU adjusting the stop screw all the time it idles - it's simply a speed control - it does it by adding or subtracting air at idle.