Re: TOP END REFINISHING
 

Split BLMs are nothing new for the LT-5 especially at idle. Not a reason to buy new injectors. Were these the originals or replacements? One of the issues I discussed regarding the proper injector offset. As it is, these aren't bad. Can u tell if LEARN is ON?

Re: TOP END REFINISHING
 

Don't know if this version of DM tells if learn is on or not :dontknow: Anyone?

Can't I assume that it IS on? Since the Short Term is closer to 128, than Long Term?

Doesn't 'Learn' begin a few minutes after CL starts?



No one chimed in to ID the injectors by the snappics, and I SURE don't know.

Anyway here, why did the thing turn @ 3k when I ran it with IAC dis-connected earlier? Could it have been because of the vac leak @ the plenum-PCV connector?

Re-try IAC dis-connect first thing AM...

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FWIW...after I replaced my injectors and O2's my Datamaster file CL showed both banks long term trims to be pretty steady at 128/129 L-R. Short term varied slightly about 127-130 for a 15min idle run.
I can tell you that originally I had a bad primary fuel injector (6 ohms hot) (12 ohms cold) on the left bank that gave the same rich indication that you have on your right bank Lterm. I don't know if that helps or muddies the water more.

Without knowing the part number of your injectors its a hard guess if they are original or not but I will tell you my original injectors looked pretty much the same as yours in the pics. I think I mentioned this wayyyyy back in this thread. I would ohm the primaries out cold and hot and write them down.

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Any datalogger should indicate whether LEARN is ON or not

No. You must be in C/L in order for LEARN to be on, but u can be in C/L and have LEARN OFF.



Did u disconnect the IAC OR remove it? If you disconnected it w key ON, then that will block the IAC port. Now if you have remedied the PCV leak, then only one place the air is coming from and that's the throttle blades being too far open. Let's see if it idles and at what rpm?

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I had it electrically dis-connected, AFTER key ON - not removed. And I haven't seen a readout, besides '0', in DM, for IAC yet. ??? No SES lights, including for dis-connected IAC.......................................

Will re-try IAC dis-connect again shortly here. This should be done Closed Loop? Or Open?

Re: TOP END REFINISHING
 

There is no MALF code for IAC. I would run the motor till it is warm and indicated C/L. Then shut down. Ignition ON, disconnect IAC. Ignition OFF, then Engine Start. Allow the start-up routine to stabilize timing, then check idle RPM.

Re: TOP END REFINISHING
 

Alright - went this way perfectly; idle stayed 2275 - 3k for 2 minutes.

Next?


ed.:
TPS voltage .55; IAC 0

Re: TOP END REFINISHING
 

Just trying to clarify, with IAC disconnected, warm idle was at 2200rpm? I am looking at 2 different scenarios you just posted. If O/L went smoothly, I would discount an issue w the injectors.
Remove the IAC completely and plug up that port physically making certain that no bypass air is entering. What's your idle at coolant operating temps and C/L?
Is your motor completely stock or what mods have been done

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OK - I think I understand - 'block the port' for by-pass air.

Which of the 2 internal ports is this? The port in the SIDE of the IAC bore? Or in the END of the IAC bore

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The IAC pintle has HEAVY corrosion on it. I know this did not seal.

I hit it only with solvent, and THAT wouldn't touch what I have here...

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It helps to clean the pintle and the IAC bore where the pintle moves into/out of.
And yes that is the port you block off. The outer port is the bypass air and the IAC controls how much of that air bypasses and controls idle.
So yes clean the pintle and bore. However, I would still block off the IAC port physically and see what happens w the idle.

Re: TOP END REFINISHING
 

Cleaned pintle, and re-checked CL idle. Still high - 775 - 900, SLIGHT lope.

Pulled the IAC, tapered socket in a clean shop rag, in the IAC bore, TIGHTLY, but might have still let some air by???.

CL idle at 1475, steady, occasionally touching 1500.

Re: TOP END REFINISHING
 

Well, first there was a moth, and now, an O-RING!!! (except I got the moth with the Shop-Vac)

It was idling at about 2,300, and I pulled the IAC, to put my finger on the IAC-to-plenum inlet, to MAKE SURE I had a seal.

A tip: DON'T DO THAT.

Never even saw the O get pulled; it was so fast. She never even hiccuped. I smelled a puff of burning rubber, and saw the missing O at the same time. By the time I shutdown, and smelled the exhaust tips, I couldn't even tell which side took it.

http://i149.photobucket.com/albums/s...s/fainting.gif

Anyone wanna' buy a Z? Complete with documented F*^#@-ups!!! I might even pay ya for removal...



Anyway, I got a new O-Ring at Advance, same size, slightly fatter, plugged it in, and everything SEEMS like it was before. Idling about 900, occasional lope up to 1,000, down to 825.

Would the burned rubber foul the O2 sensor? DM O2 readout didn't show anything different after the O pulled (I had watched O2 readout before).

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Schrade, in the above quote you indicate Open loop idle issue. Correct?

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No Franke; it had gone to Closed Loop about a minute before...

It ran smoothly, although high, and just before CL, it began a mild lope - 25 - 50 rpm swing, then increased as it hit CL.

Why? What do you see?

I edited that post as it warmed up.

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Ok - FSM irregular idle diags flow chart -

#1 vac leak [no?]
#2 ECM ground NO WAY...
#3 throttle linkage NO WAY
#4 low FPR vacuum [no?]
#5 IAC...

Does DataMaster have 'IAC driver' capability?

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Ok. My error on open loop. Sorry to mis-direct on that.
Datamaster is not able to drive the IAC as it is just a diagnostic tool to show what is going on with various sensors and parameters. You will need a tech 1A tool or a Mastertech 3100 to operate the various components and simulate sensors etc. It is also possible to simulate most of the various sensors and drivers electronically if ya know what function they perform and how they do it.
So it appears at this point that the CL threshold is reached and then the idle begins hunting. Does Datamaster show a steady IAC count? Is it steady at 0 or approx. when in OL? Does it move around a lot in CL at idle. I looked at my DM files and IAC was 0 in OL and CL with 725-750 RPM idle speed.

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Anyone got a Tech 1 that I can borrow?

I'll forward full cost Money Order up front, and you can return however much is appropriate after I get it back to you there...

PM me on it if you can...

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Alright; IAC blocked TIGHT (cold motor)...

Idling @ 875, smooth as silk...

Post 3 minutes - loping irregularly 125rpm's, sometimes still very smooth, from 825 - 950, still OL...

Now CL; started about 200 rpm lope IMMEDIATELY when it went CL...

2 minutes CL; settled down with only a 75 rpm lope - 900 - 975...............

3 minutes CL; smoothed out real well - 950 - 975.

5 minutes CL; now holding 975 tight as a drum.

9 minutes; now loping 900 - 1075 rpm's

12 minutes; now loping from about 875 - 1125. Shutdown...

Thoughts?

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Chuck,

OK doesn't look as there is a vacuum leak however, it sounds like the throttle blades may be too far open or allowing some additional air. I assume the TPS is at ~.55v. Now if you can back off the throttle stop 1/2 turn and see if that makes a difference. Leave the IAC port blocked.

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AND my IAC block; a 13mm socket with masking tape came out MUCH easier than it went in.

So that might account for the lope when it went CL, warmed up, with IAC bore opened up by heat. But it still never went below 875, OL or CL...

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Yeah so I think it may be time to look at how the throttle blades are situated in the bore. It doesn't take much.
You removed the primary throttle as well as the secondaries? Can you try pushing on throttle lever itself to see if you can close throttle further manually?

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I did NOT remove the primary shaft or the primary butterfly.

I cannot manually pull the secondaries closed any further.

Just got off of the phone with Marc; he suggested something I had actually thought of - blocking the secondary ports in the TB. He said if rpm's then go down LESS than 100 rpm's, then the TB is fine.

If the rpm's then drop MORE than 100 rpm's, then it needs attention.

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Makes sense. Have you checked throttle blade clearance in the bores? Also, if you have motor running and blip the throttle, how does motor behave returning to idle?

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I'm going out on a limb here.....

Before you remove your "ticket stopper"

unplug the TPS to keep it out of C/L just to see if the ECM is inducing the idle speed based on errant readings, such as vacuum leaks. An engine can still run pretty smooth, although idling high from vacuum leaks.

Assuming the idle speed is still high, start checking for vacuum leaks in not so normal areas, using a propane torch with a rubber hose on the end (remove the burner tip & put the rubber hose on the small pipe from the valve)

Check around each injector where they fit into the injector housings, the T/body shafts where they fit through the throttle body, the Dual PCV hose system, from the inj hsngs, all the way into the plenum, the connectors to the 2 hoses into the plenum under & behind the t/body area...... and anywhere else you can get to, including all of the intake gaskets joints.

Re: TOP END REFINISHING
 

The 'Ticket Stopper' dropped my rpm's to 475, STEADY. although rough, like a cammed motor.

Looks like I blew the TB re-assembly. I could NOT see light through the secondaries, but, the Ticket Stopper doesn't lie.

I'll cut out the IAC opening, and see how that effects idle, before shipping the TB off to Marc for a re-work.

Thanks again there Dom, for the phone time there - LOOKS like this thread is about ready to close.............


ed.:
Just saw your post here Jerry; got it. Should I leave the IAC port blocked as well, before doing your test? She would barely run as it was, and actually DID cut off after about 7-8 minutes, while on the phone with Dominic there...

Re: TOP END REFINISHING
 

I could probably use a rebuild on my throttle body also, but my solution was to restrict the PCV hose back to the plenum. I y-ed the hose circuit to a filtered can so the PCV can still flow out in volume during hard accel. But it did drop the rpm's 100 or so at idle and got some positive IAC counts.

seems to be a common thing on these engines.

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Sounds like an LT-5 idling. Who knew?

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Looks good! Glad you are getting it sorted out.

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...and then again, perhaps I did NOT blow the TB re-assembly.

I pulled it, and took a close look in the TB 2' bores. There was some particulate jam HOLDING OPEN THE SECONDARIES, surely enough for a vac leak through them... And I had never worked the 2' s, such that they pulled through.

:confused:

Looked like tiny grains of sand, Black. Where it came from, I cannot guess. I thought I had every little piece spotless sterile clean since the beginning. Even conscious of grit falling off of my sweatshirt sleeves (you learn about that when you spend 5 weeks polishing a Black '94 by hand - 2000 grit, rubbing compound x 3, polishing compound x 4, 5, wondering where new swirl marks come from).

So the TB is re-cleaned. Ready to bolt back together again...

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Re-assembled, TB 2' bores cleaned (again), idling OL @ 750...

...awaiting CL.

PLEASE - let's bury this thread...

I KNOW that the Cruise lope was the vac leak at the under-plenum vac connector........

Only the hesitation was the original issue here...

Showing CL @ 138 coolant temp ??? Heat on 90'; heater fan pegged...

Still idling 750, 153', CL, should be lower with pump load for automatic tranny...

I bumped up the throttle; she wouldn't drop back down below 1,400.

^&%* :censored:

Shutdown; tried to work the throttle, it was stuck. Broke it free, fired it, and the went right up to 3-4krpm's. Shutdown. Binding somewhere here...

Pulled the accordion, and the primary is stuck open.

???

Closed the primary, and she's got a swing - 750 - 925. IAC readout '0'.

Thought the fouled secondaries might have been the answer, but apparently I DID blow TB re-assembly here...

Re: TOP END REFINISHING
 

I'm going to be a 'poser' for a while here...

I'm gonna' re-install the 'Ticket Stopper', since it idles perfect in that manner, do 100 miles or so, check everything out - Cruise, hesitation issue, then send the TB off to Marc for a re-work here...

SO far, everything else BEHIND the TB is perfect.

Any suggestions?

Re: TOP END REFINISHING
 

Send it to Marc for a first class rework. There is definitely something wrong with it. You didn't adjust the primary throttle plate so unless there is something mechanically wrong with the return mechanism (spring and linkage) it should close down to idle stop.
You did say in the previous post that there was some black gritty jam preventing the secondary's from closing all the way did you get that cleaned out? Did the TB work ok off the car as far as mechanical operation? No binding etc?

Re: TOP END REFINISHING
 

The 1' throttle binding was the TB coolant crossover tube that I routed over the A/C compressor. It had jumped a casting ridge on the comp. Fixed.

Prepping a road test with the 'Ticket Stopper', to confirm Cruise, and check the hesitation issue............

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Spun up again, primary free from binding, spinning like a top - with the restrictor gasket.

Road test for the cruise lope, and check the hesitation...

EXCEPT FOR A FRESH PROBLEM - BLINKING A/C CONTROL.

http://c1.cowcow.com/img/4-15519436-0-1-1

Recycled battery power, started up, no flashing, then flashing, now it's steady again.

No SES in DIC, no DataMaster codes.

Would this store as a CCM 'H' code, for display in LED dash?

Anybody?

Re: TOP END REFINISHING
 

Schrade, if you think you have a fault code check FSM page 1C1-2 diagnosis. Tells you how to check.

Re: TOP END REFINISHING
 

Schrade, how did the road test come out on the primaries only? Hesitation gone @1.5% idle?

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What's up Franke...

I did a few laps around my neighborhood, then 16 miles round trip to get Safety Inspection - that's a go, no problem.

Hesitation, observable under light throttle, is NOT gone.

The same hesitation that's evident at LIGHT rpm increase from idle is (and was before) evident in Reverse, and in Drive. Under light throttle, it is (as was before), evident as it shifts, and begins rpm climb again.

I cannot accept a vacuum problem, or mechanical problem. It HAS TO be electrical, related to the auto controller module, and the circuit that's singing, as TPS BEGINS range of motion (the 'singer', is in the tranny). Tranny controller diagnostic shows no tranny controller codes. Tranny shifts perfectly, and responds to changes in setting as well.

Everything NOW, with the 'Primary Only' gasket in place, is the same as it was before the plenum pull, with secondaries operational (except for the dirt).

And the Cruise lope, although I didn't engage Cruise, I'm sure is still there, and I'm certain it's also related to the hesitation / TPS circuit.

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Did the HVAC issue go away?

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Yeah - had to be a fluke. Problems never 'go away' otherwise...

I'm gonna' get a vid of the singing TPS, and try to get feedback from TCI and RPM Transmissions.