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Old 03-15-2009, 04:03 PM   #16
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Quote:
Originally Posted by 03slowZ06 View Post
Jake. His 93 is batch fire so the injector connection order is not to important just that it is on the properside. Other then that we are on the same page.
Thanks for that. I thought all LT1s were sequential fire. I just found out that sequential didn't start until 94.

It's hard for me to keep up with all of GM's changes.

Much appreciated. Live and learn.

Jake

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My son, Ryan M. Cameron, graduated from West Point on 22 May 2010! He was commissioned as a 2nd Lieutenant and I pinned on his first pair of "Butter Bars" PROUDEST DAY OF MY LIFE!!

1996 Vette, 388 CID LT1 (3.75" X 4.060"), Eagle Internally Balanced Forged Crank, Eagle 6" Forged Rods, SRP Forged Pistons, CompCams XFI 467 Cam (230/236 @ .050), Scorpion 1.7 RRs, AFRs ported to 212 ccs (304 cfm @.600), Match Ported LT1 Intake, SVO 30# Injectors, BBK 58mm

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Old 03-15-2009, 04:30 PM   #17
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thanx for the abundant amount of info here fellas...im gonna answer these inquiries in order of importance or atleast what i percieve to be most important lol...first off the knock sensor..i was under the impression that the sensor in the head coolant port was it..not jus cause i thought so but cause of a post that said it was there on 93s..but at the parts store i looked at a replacement sensor and it was def. the one at the bottom pass. side in the block...im not to sure what the hell the one in the pass. side coolant port is (maybe a temp. sender for the fan since i know the pcm coolant sensor is in the w. pump n the gauge sensor is in the drivers head).either way im gonna replace the knock and see if it makes a difference even though the tuner told me its shouldnt even show up..next would be the map sensor issue...i replaced the map sensor with a new one and the code went away..i also replaced both o2s at the same time(this was all done since the last time i posted)..it def. made a big difference in running characteristics...I.E it now fires up in less then 5 seconds of cranking with no throttle application but it surges hard at idle between 600-1200 rpm and then shuts off after about 6 or 7 surges when the rpms drop...when i rev it i can almost hold it steady around 2500 but it still drops a little then picks back up..i doesnt seem to want to rev all the way out though..plus i dont like pushin it when its running bad like this..i also tried puttting a load on it by putting it in drive and loading the tires but it just shuts off when i do that)...next issue bein TPS reading ..i realized that at one point i had the idle screw on the T.B turned up to try to keep it running and thats why it was a lil high..i turned it back down and the sensor now reads .65 at idle...as far as having the tune for larger injectors the answer is yes..i filled out a whole spec sheet when i ordered my tune which had everything from airflow from heads to cam specs to weight of car and tire size etc. etc. etc..it went pretty indepth into my mods and i was convinced that with all that info this guy could get it close..b..( the car actually ran better with my stock chip in it when the motor first went in)the night i first started it i got oil pressure through the motor with no ignition then i plugged the coil back in and cranked it and it fired right up and held a pretty nasty idle for atleast 45 minutes ..i then spent a week waiting for this chip and when it came i put it in and its been hell since then)...as far as the injector wiring goes im pretty sure they are hooked up right..at one point a couple weeks back i posted a question about how to tell which are right wires for the injectors cause they are all the same color...im pretty sure i remember someone telling me that me year is batch fire and that u cant get it wrong unless u were too turn the whole injector harness backwards ...obviously this is nearly impossible..anyway thats pretty much what i got so far..i wanted to update you guys about the changes after the map and o2s sensors bein put in..im waiting to get my scanner back in a hour or so and im gonna read all the values again and see what has changed then ill repost my results later..its def. gettin closer to what i need...after i get the knock issue resolved i have a local speed shop who specializes in gm and has all the datalog and burning programs for my car..they also have a awd mustang dyno on which there gonna tune and dyno my car..i just didnt wanna take it with a bunch of little probs. that they had to fix it b4 it was even worth dynoing..thanx for all the help ..
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holley tb, aeromotive reg. and rails,in-tank&in line pumps,LT's ORY and 3 inch flowmaster,Hughes manual 700r4 with 3200 stall and anti baloon plate ,3.73's,tubular lca's,adjustable torque arm reloc.......more to come
On The Stand...... Fresh 11 to 1 forged 350 lt1 wit trick flow 195 cc 2.02/1.60s,edelbrock rpm air gap intake ported,comp cams 467 grind, 1.6 scorpion roller rockers,`30# bosch injectors .. car has also been caged wit S&W 8 point and teched out for 9.90s
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Old 03-15-2009, 05:01 PM   #18
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Geez, break your responses into paragraphs. It's murder to try to read.

Don't bother to post a single O2 reading, unless the value does not change on the scanner. A single reading is meaningless, since they change many times per second.

You can get that MAP code from the engine simply idling low or dying. There may have been no problem at all with the sensor. Monitoring MAP with a scanner will tell you if it is working properly.

Also, your fuel pressure should be in the normal range of 41-47 with the vacuum hose removed and even less at idle. If it is over 50 at idle, then you might be dumping in too much fuel and that could be choking you down.
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Old 03-15-2009, 07:35 PM   #19
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On the L98 engines, the TPS voltage is checked/set with the engine OFF and ignition key ON. Your engine may be the same. Of course, this is the perfect time to have a Factory Service Manual which would tell you exactly how to set/check it.

From all I've read, MAP systems are much more difficult to tune than MAF systems. One of the things many guys complain of is surging which they claim is usually caused by the camshaft. I don't recall what was specifically identified as the cause - duration, overlap or Lobe separation angle - but hopefully someone will chime in with more info on that.

From personal experience, another cause of surging is a vacuum leak. Have you checked to see if all the vacuum hoses are connected and none is leaking? How about a possible vacuum leak at the intake to heads mating surfaces; throttle body to plenum, etc.

If your cam is the CompCams XFI 467, it's the same one I installed. It called for a programmed idle speed of 900 RPMs in my 388 CID. Bryan at PCMFORLESS re-programmed my PCM and it starts and idles without a hitch; however I'm running a MAF system.

I agree with Shoebox's fuel pressure recommendation info. That's about the same as the L98 engines call for.

Try to address the fuel issue soon so that you don't carbon up the new 02s.

Then sensor in the passenger side head is for the dashboard temp gauge.

Be sure to disconnect the battery for about 30 seconds to clear any stored codes OR you may have to clear them using the ALDL - not sure what you 93 calls for.

I'm just brain-storming this trying to give you some other things to consider.

Seems like you're getting close.

Jake

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1996 Vette, 388 CID LT1 (3.75" X 4.060"), Eagle Internally Balanced Forged Crank, Eagle 6" Forged Rods, SRP Forged Pistons, CompCams XFI 467 Cam (230/236 @ .050), Scorpion 1.7 RRs, AFRs ported to 212 ccs (304 cfm @.600), Match Ported LT1 Intake, SVO 30# Injectors, BBK 58mm
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Old 03-15-2009, 11:20 PM   #20
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well i got a little more info and other then that im still fairly lost here...the o2s went right back to the same non-changing value of 102 for the left and 4 for the right..i know u said not to post that shoebox but i didnt see anything else related to the 02s that i could write about..however i did monitor and record some other stuff..
LEFT BPW (Ms)between 5.0-8.0 RIGHT BPW (Ms) between 5.0-11.0
MAT 13 DEG. C
MAP (KPa)32-80(32 IS @ IDLE RPM AND IT FLUCTUATES BETWEEEN 63-80 WHEN REVVING AROUND 3000 RPM)
BARO(KPa)4.98
SPARK ADVANCE @HIGH IDLE(APPROX. 1200 RPM) 20 DEG.
SPARK ADVANCE @3000 RPM FLUCTUATE BETWEEN 38-40 MAX 44 (I CANT HOLD STEADY SO IM FEATHERING THE PEDAL TO GET THIS READING)
KNOCK RETARD 9 DEG. NEGATIVE
EGR DUTY 0%
AIR CONT. SOL. GOES BACK & FORTH BETWEEN PORT. AND DIV.
OIL TEMP -37 DEG. C
FT CELL 16-18
I.A.C POSITION 160
LO RES. SIG. BETWEEN 15.0-21.0
I.A.C LEARNED 32
I.A.C DIRECTION FORWARD
.....im not sure if any of this is helpful but its better then just guessing at this point..after changing the map and o2s it seemed to get alot more responsive when first starting it and when u tap the pedal...but it still wont hold an idle..also what i realized is that when i give it quick taps to keep it alive it does rev up but not very crisp..when i give it more then 10-15% throttle from idle it pops and backfires bad ly and shuts right off..and if i try to put it in gear it shuts right off..i have no clue what it is..tomorrow im gonna check the fuel pressure as instructed by you guys and also double check for vaccuum leaks..i was also thinkin to go nderneath and make sure everything is cool wit the air filter in the fenderwell..after that i really dont know what else to do..lemme know what u guys think of the updated info and maybe some other troubleshooting i can do ..thanx for all the help
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holley tb, aeromotive reg. and rails,in-tank&in line pumps,LT's ORY and 3 inch flowmaster,Hughes manual 700r4 with 3200 stall and anti baloon plate ,3.73's,tubular lca's,adjustable torque arm reloc.......more to come
On The Stand...... Fresh 11 to 1 forged 350 lt1 wit trick flow 195 cc 2.02/1.60s,edelbrock rpm air gap intake ported,comp cams 467 grind, 1.6 scorpion roller rockers,`30# bosch injectors .. car has also been caged wit S&W 8 point and teched out for 9.90s
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Old 03-15-2009, 11:33 PM   #21
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Bud i don't know all of those but adjust the tps. Also maybe try adjusting the throttle blade open a little then set the tps. And see what it does. It wouldn't hurt to try. But as for your o2 problem i have no idea what the deal is with that besides what o2's did you put in it?

I think it is just your tune by the sounds of it. Have you tried to run it on the factory tune at all? Might be worth a shot though you might have to put stock injectors in.

But other than that i have no clue but if you want the link for adjusting the tps i can find it somewhere.
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Old 03-15-2009, 11:41 PM   #22
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Based on the maxed out IAC counts, it is not getting enough air for the fuel that is being dumped in. Get the fuel pressure to where it is supposed to be and maybe crack the throttle blades open a little more (you will have to readjust the TPS).

Those Aeromotive AFPRs are notorious for going bad.
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Old 03-16-2009, 01:06 AM   #23
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Let's first try to get it to idle, then we can tackle the 02 problem. The engine should idle even with non functioning 02s, it's just that system won't go into Closed Loop.

Yep, your IAC counts should be in the 20s, not 160. Idle is being seriously starved for air.

Use the little screw on the driver's side of the throttle body to open the butterflies which should allow the engine to idle.

The TPS voltage should be reset to right at .67 but not higher or a code may set. It may even set a code at .67, so if you get a TPS High code when you set it to .67, try dropping it down to .62 or so.

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1996 Vette, 388 CID LT1 (3.75" X 4.060"), Eagle Internally Balanced Forged Crank, Eagle 6" Forged Rods, SRP Forged Pistons, CompCams XFI 467 Cam (230/236 @ .050), Scorpion 1.7 RRs, AFRs ported to 212 ccs (304 cfm @.600), Match Ported LT1 Intake, SVO 30# Injectors, BBK 58mm
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Old 03-16-2009, 07:40 AM   #24
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gotcha..im headin to work now so ill have to sneak off a couple times and mess with it....but its good toknow that someone can take those numbers from the scan and actually interpret them...my throttle body actually does have a prob. anyway...when its at idle and u go to open by hand it sticks and then breaks free...i noticed that the shaft that holds the butterflies moves around an awful lot so whatever bushing or bearing it has must be all bagged out...ill look real close into that..thanx guys ...ill post more later today
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holley tb, aeromotive reg. and rails,in-tank&in line pumps,LT's ORY and 3 inch flowmaster,Hughes manual 700r4 with 3200 stall and anti baloon plate ,3.73's,tubular lca's,adjustable torque arm reloc.......more to come
On The Stand...... Fresh 11 to 1 forged 350 lt1 wit trick flow 195 cc 2.02/1.60s,edelbrock rpm air gap intake ported,comp cams 467 grind, 1.6 scorpion roller rockers,`30# bosch injectors .. car has also been caged wit S&W 8 point and teched out for 9.90s
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Old 03-16-2009, 08:11 AM   #25
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Originally Posted by scubasteve View Post
gotcha..im headin to work now so ill have to sneak off a couple times and mess with it....but its good toknow that someone can take those numbers from the scan and actually interpret them...my throttle body actually does have a prob. anyway...when its at idle and u go to open by hand it sticks and then breaks free...i noticed that the shaft that holds the butterflies moves around an awful lot so whatever bushing or bearing it has must be all bagged out...ill look real close into that..thanx guys ...ill post more later today
The sticking and breaking free is probably because it's not adjusted open enough. Opening the blades using the little minumum airflow screw, should cure that.

The wobbly throttle shaft is something different. It could be causing a vacuum leak. I sold the TB that I removed from my 86 415 when I moved to a 52mm TB to a Forum member because the buyer was having the same problem with his. If it turns out you need a TB, I still have the stock one that came off my 96 when I went to a BBK 58mm.

Jake

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My son, Ryan M. Cameron, graduated from West Point on 22 May 2010! He was commissioned as a 2nd Lieutenant and I pinned on his first pair of "Butter Bars" PROUDEST DAY OF MY LIFE!!

1996 Vette, 388 CID LT1 (3.75" X 4.060"), Eagle Internally Balanced Forged Crank, Eagle 6" Forged Rods, SRP Forged Pistons, CompCams XFI 467 Cam (230/236 @ .050), Scorpion 1.7 RRs, AFRs ported to 212 ccs (304 cfm @.600), Match Ported LT1 Intake, SVO 30# Injectors, BBK 58mm
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Old 03-16-2009, 08:41 AM   #26
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im gonna look into all this cause now that i think about it i have a good amount of hissing around my tb...i originally percieved it as a vaacuum leak but i never found it...my fatherinlaw owns a junkyard with about 3000 cars in it so im gonna pull a stock tb today and see what difference it makes
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holley tb, aeromotive reg. and rails,in-tank&in line pumps,LT's ORY and 3 inch flowmaster,Hughes manual 700r4 with 3200 stall and anti baloon plate ,3.73's,tubular lca's,adjustable torque arm reloc.......more to come
On The Stand...... Fresh 11 to 1 forged 350 lt1 wit trick flow 195 cc 2.02/1.60s,edelbrock rpm air gap intake ported,comp cams 467 grind, 1.6 scorpion roller rockers,`30# bosch injectors .. car has also been caged wit S&W 8 point and teched out for 9.90s
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Old 03-16-2009, 10:11 AM   #27
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scuba, I know you have a potload load of info coming in and multiple problems, but don't forget the knock sensor.. 20* at 1200 rpm is low for your cam 230/236 113 LSA. That 9* retard is hurting your idle. I run my TPS 0% voltage at .75V, and my closed TPS timing 28* at 800 rpm and 30* at 1200 rpm. To test the KS circuit pull wire off, w/ign on you should have +5V at the wire. Go to resistance scale and meter KS terminal to ground you s/have 3.3K to 4.5K ohms.
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Old 03-16-2009, 11:54 PM   #28
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ok so i tried a couple of the things you guys mentioned tonight...they are as follows

..i went after the knock sensor issue first..i went under the car and disconected my knock sensor connector..i used the multimeter to read the resistance of the sensor ..it registered somewhere around 4 (its not digital so its hard to get an exact reading)...then i tested the wire by grounding the meter and clamping the wire with the ignition on..it didnt register anything on the meter..i noticed that the wire was skinned and a section of bare wire was exposed so imnot usre if this could have grounded at one point and shorted something..so i guess i need to know the protocol for testing this wire at the comp. to see if it even puts anything out...
i did trace the wire to the topside of the car and tested it there to get the same result of no voltage..also as a quick note ..i had meantioned before that someone told me i had a K.S in my pass. head and one you guys said thats the temp. sensor for the gauge..but i have a sensor in my driver head which i thought was for the gauge...the reason i mention this is cause i cleared my codes with my snap on scanner tonite and the only thing left was a Info Flag that said "both ESC sensors open"..so i got a temp. sensor for the comp. in my water pump and a gauge sender in my driver side head for the gauge..what is the sensor in my pass. side head (a second knock as indicated by the scanner or a third temp. sensor?)

on to the next issue..i took off the T.B and inspected it..turns out the shaft is pretty solid and the billet throttle linkage was loose on the shaft but its tight now..i then advance the idle screw as far as it could go to open the butterflies more at idle (which didnt seem like much cause u can barely see an opening at the top or bottom of the butterflies)..then i reemed my TPS holes for adjustment and reset it at .66 with the idle screw turned out..when i fired the car it did seem a little different but still wont hold an idle ..it just surges a couple times then shuts off..i took note that before i ever started it tonite the iac position was at 151 and learned was 32..after firing it up and keepin it alive for a couple minutes the iac really didnt change and stayed between 140-160 and direction stayed forward...

also the map code showed back up so shoebox was right on with that one ..when the car cant idle and keep stallin it sets off a map code...

im not sure what to even try next until i get some feedback about the K.S issue and how to fix it..but id appreciate you guys takin this info and givin me some feedback...
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holley tb, aeromotive reg. and rails,in-tank&in line pumps,LT's ORY and 3 inch flowmaster,Hughes manual 700r4 with 3200 stall and anti baloon plate ,3.73's,tubular lca's,adjustable torque arm reloc.......more to come
On The Stand...... Fresh 11 to 1 forged 350 lt1 wit trick flow 195 cc 2.02/1.60s,edelbrock rpm air gap intake ported,comp cams 467 grind, 1.6 scorpion roller rockers,`30# bosch injectors .. car has also been caged wit S&W 8 point and teched out for 9.90s
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Old 03-16-2009, 11:57 PM   #29
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oh yeah one last thing ...i didnt turn the fuel pressre down cause my gauge is terribly innacurate (its brand new but is a pep boys cheapie brand)..im gonna borrow my freinds snap on gauge that doesnt fluctuate 10-15 psi at idle lol..thanx for all the help
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holley tb, aeromotive reg. and rails,in-tank&in line pumps,LT's ORY and 3 inch flowmaster,Hughes manual 700r4 with 3200 stall and anti baloon plate ,3.73's,tubular lca's,adjustable torque arm reloc.......more to come
On The Stand...... Fresh 11 to 1 forged 350 lt1 wit trick flow 195 cc 2.02/1.60s,edelbrock rpm air gap intake ported,comp cams 467 grind, 1.6 scorpion roller rockers,`30# bosch injectors .. car has also been caged wit S&W 8 point and teched out for 9.90s
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Old 03-17-2009, 04:52 AM   #30
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Here I go again, not being sure how different our two engines are but: My 96 has two knock sensors, one each side of the the block. The knock sensors are in the block, not the head. Your car may have two knock sensors too, both will be in the block. Don't let what someone else told you continue to confuse you. Kick it to the curb.

On my 96, the Knock Sensor module is accessed from the underside of the PCM. Many guys swap the LT1 module for the one which came in the LT4. The L4 module has been reprogrammed and is not as sensitive to false knock. Knock, whether actual or false, will cause the PCM to retard the ignition timing. The LT4 module is a direct swap; nothing else need be done.

Some even splice a resistor into the knock sensor wire to FOOL the computer into thinking all is well. I did it on my 415 86 Vette and it works like a charm. The resistor allow the voltage the PCM is looking for to always be there, so no knock retard of timing will take place.

On L98s, one of the senders in the passenger side head is for the dash board coolant temp gauge and the other is to turn on the fan. GM changed that arrangement at some point, but I forgot when, but in any case, what's in your head is not a knock sensor.

Knock sensors look entirely different, so they can't be confused with a coolant temp sender. Just unplug the wire to the coolant temp sender in the head and your coolant temp gauge should either peg or show no temp at all. I don't even have anything screwed into my driver's side head; other than a plug in the hole. No sender or sensor. I'll check my son's 96 later today to see if his is the same.

Your IAC pintel could be stuck or sticking. You can unscrew it and remove the pintel with your hand by pulling on the pintel (the tip) with moderate pressure which rocking it from side to side.

Once out, you clean off any carbon buildup, then re-insert it using reverse pressure. The pintel should be re-inserted until the tip is no more than a certain distance extended. If it's extended too far, it'll bind. Seems the distance is 1-7/8", but someone should verify that distance for us. Anyone Know for sure??


I have to go from memory on this, too but there is a way to manually reset the IAC.

If I remember correctly, you turn the ignition key to ON but don't start the engine. Then, with the key still ON, you unplug the IAC. Now you start the engine - with the IAC still unplugged; the engine may take a coaxing to keep it running since the IAC isn't working to control idle speed. Then set your desired idle RPM with the TB screw, then shut down the engine and re-set the TPS voltage (TPS voltage is set with the engine OFF, key ON). Then plug in the IAC; the restart the engine. You then drive the car a normal speeds and the IAC automatically re-adjusts itself.

It's been a long time since I did a manual reset and even then it was on a L98 engine, not a LT1; the procedure should be the same though. I believe I posted the exact procedure on the CorvetteForum (forums.corvetteforum.com) several years ago in the TECH TIPS section. The procedure may even be posted here.

I do recall that if the IAC is plugged back in while being unscrewed from the TB, the pintel will shoot out, across the room, LOL Ask me how I know.

If you want to track down that tip - and MANY others as well- go to the CF, then to the C4 section. At the top of the page there are several buttons that have drop down menus. One of those menus is entitled Tech Tips; the procedures are listed in there.

There's a vacuum bib directly in the center of the intake manifold, right under the TB. On my engine it's for the PCV. Check it to make sure the bib or rubber hose isn't leaking. Many times the hose will come off or dry out, crack and cause a vacuum leak.

I hope some of this helps solve your problem. I figure if we brain-storm this enough it will eventually lead us to the cause.

Jake

West Point ROCKS!
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My son, Ryan M. Cameron, graduated from West Point on 22 May 2010! He was commissioned as a 2nd Lieutenant and I pinned on his first pair of "Butter Bars" PROUDEST DAY OF MY LIFE!!

1996 Vette, 388 CID LT1 (3.75" X 4.060"), Eagle Internally Balanced Forged Crank, Eagle 6" Forged Rods, SRP Forged Pistons, CompCams XFI 467 Cam (230/236 @ .050), Scorpion 1.7 RRs, AFRs ported to 212 ccs (304 cfm @.600), Match Ported LT1 Intake, SVO 30# Injectors, BBK 58mm
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