jretzky

Hey!~I see that Clint had a problem with low idle and stalling problem.
It turns out the DFlintstone and Cruiser were working with him.
He had earlier checked his vacuum line to the MAP sensor and it appeared to be good. I checked mine and it's good.
One thing Clint stated was that his hard line coming out of the MAP sensor had a point where the hard plastic line was spliced with a soft rubber hose. Mine has been spliced also. I wonder if someone splices that line caused the problem?
Low vacuum to the MAP sensor appears to make the engine run rich?
I plan on getting a new vacuum line.
Thanks!~John

syncview

yes the vacuum line should be perfect as in it shouldn't leak

DFlintstone

I have two short splices of standard vacuum line on my MAP tube. I'm not sure at all what Clint had, but vacuum line normally does not collapse under vacuum.

jr, sometime when it's warm, sit there and listen to the idle. See if it fades, stumbles, catches and almost rev's a little, repeats that, every 20 seconds or so.

cruiser54

Fuel mixture most affected by these 3 sensors in this order:
MAP
CTS
IAT

What's your fuel pressure, and are the injectors original?

DFlintstone

How sure are you the IAT is above the 02? In my (limited compaired to yours), experience with my Renix, The IAT seems to be a pretty minor player. In any case, ultimately it's the 02 that get's it trimmed. (if those others feed it something it can handle)

EDIT, Added. I was wondering if the IAT might come into play more in seriously cold weather, like send to the ECU, "head south now, it's friggen 5* out there!"

cruiser54

We're talking pig-rich here.

DFlintstone

Gottchya'....the "post 81 blues" Isn't this the thread where the guy never adjusted his TPS?

jretzky

Ok!~been looking at the procedure for the TPS.
Cruiser what lead goes on what when checking the out put voltage?
You never said, so I figure the black lead would stay in the B and the red lead would go into the C wire.


For a lot of us old farts...you didn't mention anything else about cleaning the TPS?
I thought us Jeep owners were into that...
Another thing for us that didn't know it, on the multi-meter mine being a Sun the lowest setting for volts AC is 200. The position you set it on says "V~" & either 200 or 600. I found my instruction book. The TPS (manual trans) here are $130. Haven't checked on the auto trans ones.


DFlintone- I am getting around to this (adjusting the TPS) when I understand what the heck I am doing.
Thanks!~for the offer to help.


Then on to the other sensors. I really want to lean out this engine.
Also is it recommended to replace our fuel injectors, if they never been replaced?
It is the old, "leave well enough alone" or are you guys sticking to 4 is better than 1 injector holes.


My engine is running smooth and the only reason I am continuing is because my spark plugs are black and I can't stand the strong exhaust.
I am learning a lot also.
John

cruiser54

Instructions are clear on TPS.
Never clean it.

746 Volvo injectors.

DFlintstone

Hi John, just trying to be direct, not rude!

First off, I don't think anyone suggested you buy a TPS. (pet peeve!). If Yours will not adjust, you can use the cheaper one for an automatic. You just will not use the square "trans side" plug. Also it likely is not your problem, but IS something to check adjust at any time, and ruling it out to trouble shoot can only help. (and no, you can't clean it).

I can see where Pete need my help there. "A" is the Feed "Reference" voltage. B is the Ground, (whitch you verified has roughly one ohm or less to battery neg), And its "C" which, is the adjustable output voltage. (by rotating the TPS). So back-probing a and b you get say, 4.8. You pick up a calculator, punch 4.8 X 17%.= .81 in this hypothetical case. So "B" being it's ground, and "C" being the output, you turn it till you see .81 between c and b.

A minor booger you might find here is as you tighten the screws it changes. Get them snug, then tap with a screwdriver handle to get closer before tightening.

Is that Sun digital? We are talking 100 th's of a volt, 1/10 th's of an OHM here. Even the $5 Harbor Freight Digital meter works, or $20 ish for something handy.

I rarely tell anyone to buy anything. Buy some 746"s. You will love them, and I think they will pay for themselves as well. CPS under .35 AC Volts? I bought new instead of trying Cruisers mod because my wires were melting. Your call there!

cruiser54

I don't need any help. Everyone else gets it.

DFlintstone

There's proof how slow I am! ^^! (!/2 hr!)

DFlintstone

"Key ON, back-probe the connector at wires "B" and "C". Measure the voltage. This is your OUTPUT voltage."

Granted, it can be inferred that C is the output voltage, but clarifying it's coming from C wouldn't hurt!