I have no clue... what the deal is.... Idle sucks.

[RSpengler]

I hate to sound like a broken record about my problem and add yet another useless post that no-one replies to, but Im at my wits end (and my wallets).

Brand NEW:
IAC
ICM
Injectors (50#)
MAP (3 bar)
prom (Ultimate)
plugs

NEW 2 months ago, before my rebuild, with only 3000 miles, maybe less on them:
Conrad Cap & rotor, ATR wires, MSD GM blaster coil

Tested:
valve lash
Timing set to 0* with the Tan/black wire disconnected
Fuel Pressure tried from 30-50psi to no avail / fuel pump provides plenty of pressure
TPS reads .50 fully closed / 4.23 wot
Took my exhaust / Cat off to see if it was clogged, it wasnt.

Problem:
Truck refuses to idle. If I give it part throttle, like just a 1/4" on the gas pedal, it will idle, only its not really idling, because my foot is on the gas to keep it from stalling.

Revs slow from under 1000 rpms, backfires (alot more now, that the exhaust is off), runs rough. (blown ECM maybe?, I dont know anybody with a syty that lives in Coloado that I could swap with to see, but my speedo did tach out all the way at 120 when I FIRST turned my car on after putting the engine in it. I took my gauges out and flipped them over to get it to come back down.)

My Anti-Lock light is staring at me constantly, nothing, not even the 2 second, 1 second, 2 second, reset trick works. It wont flash any codes either, and my brakes are stiff as hell, like there is no vaccume assist at all.

I dont know what to do other than start throwing money at it and replacing new parts with new parts. I guess tomorrow, I will go buy another cap / rotor and the cheapest wires I can find. On the inside of the rotor, the terminals do have some meltage, but I assume its from fiddling with the timing back and forth a million times.

My next idea is to fix the symptoms, just so I can drive it to Florida and escape Colorado. It involves getting an adjustable Neihoff TPS, and using the Idle set screw, push the throttle blades open and then adjust the TPS back down to 0.50. I know, everyone says, dont mess with it, the idle should be set in the chip, but I dont have the time, nor the money to burn a dozen chips till one works...

Is there anything in a distributer besides the ICM that could go bad? I noticed that the timing light likes to cut out randomly, even with a nice solid connection to the plug wire.

Suggestions, please?
Thanks,
Rob

 

[QUICK STORM]

Re: I have no clue... what the deal is.... Idle sucks.

My Anti-Lock light is staring at me constantly, nothing, not even the 2 second, 1 second, 2 second, reset trick works. It wont flash any codes either, and my brakes are stiff as hell, like there is no vaccume assist at all.

this part of your post sounds like this may be your problem. maybe the diapraghm in the power brake booster is torn causing a HUGE vacuum leak. i would maybe start here. couldn't hurt.

 

[leroy]

Re: I have no clue... what the deal is.... Idle sucks.

Did it ever run right after the rebuild?

Jim

 

[ericguy320]

Re: I have no clue... what the deal is.... Idle sucks.

I posted this before in a wont idle post before, not sure if you tried it or not. do this after you fix any vac leaks.

"have you tried checking min. idle, just turn key off jumper A and B of the ALDL (this is diag mode should flash a code 12 when in it) turn the key on then let the IAC reset for about 10 sec or so then unplug the IAC. Start the engine (should be warmed up before you do this) the engine should idle at around 500 rpm if it doesn't then adjust the idle set screw until it dose. when your done just shut it off and plug the IAC back up"

 

[SeattleSy#1255]

Re: I have no clue... what the deal is.... Idle sucks.

are you sure your ultimate chip is the 50# version?

you said your MAP sensor is good in a previous post, are your sure its a 3bar?

may want to swap ECM's with someone...rare, but they can go bad. Again, are you sure that all the pins in the ECM are straight and not bent, where one is perhaps not 'plugging in'.

are you loosing fuel pressure at all?

 

[93ty475]

Re: I have no clue... what the deal is.... Idle sucks.

swap in the stock injectors, stock chip and 2bar map....see if it runs...if it does, drive it to florida and mess with it there....I'm with Jeff....sounds to me like a bad/incorrect map sensor....my next guess would be firing order....hard to tell over the internet....

 

[RSpengler]

Re: I have no clue... what the deal is.... Idle sucks.

this part of your post sounds like this may be your problem. maybe the diapraghm in the power brake booster is torn causing a HUGE vacuum leak. i would maybe start here. couldn't hurt.

Thanks for the reply, I will have to check that out as my next option, I dont know how it could have been torn or ripped though, it ran fine before I parked it and swapped the engines. I'll definately be inspecting this, Thanks.

Did it ever run right after the rebuild?

No, I have been battling problem after problem, thinking I have it solved every time, then being stumped when it doesnt fix it... At least I will know for sure all the problems are ironed out after I do get it working.

I posted this before in a wont idle post before, not sure if you tried it or not. do this after you fix any vac leaks.

I found that post when I was searching, but was told not to mess with the ISS, as it shouldn't be the problem if it wasn't messed with. That was kind of my last ditch effort as described above, but wont I have to change the TPS with an adjustable one if I want to zero my TPS voltage back out? Anyhow Im going to give that a go tomorrow, since I have the exhaust dumping right out the downpipe, my neighbors would have a fit if I fired it up tonight.

are you sure your ultimate chip is the 50# version?

you said your MAP sensor is good in a previous post, are your sure its a 3bar?

may want to swap ECM's with someone...rare, but they can go bad. Again, are you sure that all the pins in the ECM are straight and not bent, where one is perhaps not 'plugging in'.

are you loosing fuel pressure at all?

Yes, I am sure the chip is the 50# version. I bought the map sensor brand new from GM, it is the correct part number for a 3 bar. 12223861

The pins are all straight. and the plugs are seated securely.

No, there is no loss of fuel pressure.

swap in the stock injectors, stock chip and 2bar map....see if it runs...if it does, drive it to florida and mess with it there....I'm with Jeff....sounds to me like a bad/incorrect map sensor....my next guess would be firing order....hard to tell over the internet....

I just swapped all that stuff out, in hopes of curing the problem. I had the same problem before I put the chip, 50#ers, and 3 bar in. Plus, one of my stock injectors had a cracked pintle and was clogged. I thought for sure that would be the cause. To my surprise, the problem persisted even after the bad injector was out of the equation. The MAP is BRAND NEW, correct part number. Firing order is good to go. 165432.

Thank you all very much for your responses. I appreciate it greatly.
-Rob

 

[mrweelr]

Re: I have no clue... what the deal is.... Idle sucks.

Did you swap the IAC and/or ECM yet? What about O2 sensor? Those were some suggestions made earlier. Since you already replaced the injectors, MAP, and chip, it's probably not those things. Did it idle fine with the old motor in there? Did you hook up a scan tool to see if there are DTC codes or other anomalies? Don't give up on it, you'll figure it out. We've all been there.

 

[SeattleSy#1255]

Re: I have no clue... what the deal is.... Idle sucks.

some other thoughts:

ignition module

pickup coil

Sees to me that it is timing related because you said in a previous post that the timing is erratic. Well, the timing shouldn't be erratic and that would certainly cause a shitty idle (or not run at all). Slipped balancer?

 

[RSpengler]

Re: I have no clue... what the deal is.... Idle sucks.

Did you swap the IAC and/or ECM yet? What about O2 sensor? Those were some suggestions made earlier. Since you already replaced the injectors, MAP, and chip, it's probably not those things. Did it idle fine with the old motor in there? Did you hook up a scan tool to see if there are DTC codes or other anomalies? Don't give up on it, you'll figure it out. We've all been there.

Brand new IAC, I dont know anybody with an ECM that I can swap with. I didn't do the O2 sensor, because I am still getting voltage from it, it's my understanding that the O2 sensor will not read any voltage when is dead. Yes, it idled fine with the old motor in it, even with blown ring landings and rings. I have not hooked up a scan tool, but I've jumpered the A and B terminal to pull codes, which there are none. Thanks.

some other thoughts:

ignition module

pickup coil

Sees to me that it is timing related because you said in a previous post that the timing is erratic. Well, the timing shouldn't be erratic and that would certainly cause a shitty idle (or not run at all). Slipped balancer?

Brand new Ignition Control Module. Pickup coil... Thank you, thank you, thank you, I've been asking and asking if there was anything else inside the distributer that can go bad, and I didn't know what else was in a distributer. I just looked it up and I see what it is now, but it looks like you have to pull the distributer to replace it. Oh well, its worth a shot. BTW, the balancer is good, I verified TDC with the valve covers off and the #1 spark plug out.
Thanks!
-Rob

 

[wantingasy]

Re: I have no clue... what the deal is.... Idle sucks.

Check the firing order and switch around some wires on the distributor. That exact thing happened to my car (not sy/ty) .

 

[mrweelr]

Re: I have no clue... what the deal is.... Idle sucks.

I would still hook up a scan tool to look at the parameters at idle. Maybe something will jump out at you. I can send you some DM files if you want, for comparison. Just upgrade your distributor to an MSD Pro Billet unit (#8367) and be done with it. They are awesome distributors.

 

[berzerker]

Re: I have no clue... what the deal is.... Idle sucks.

where you at in CO .

 

[SeattleSy#1255]

Re: I have no clue... what the deal is.... Idle sucks.

I don't know...to be honest, i'd be concerned that it hasn't ran right since the rebuild. It seems that you have replaced almost the entire igntion system and fuel system.

I would find someone in your area that can hook up datamaster and see what it says.

I'd also swap out the ECM. I know you said you will, but man i'm running out of ideas.

Mainly you need to see if datamaster says any codes.

 

[RSpengler]

Re: I have no clue... what the deal is.... Idle sucks.

where you at in CO .

Colorado Springs.

I'm about 80% positive that I have a bad ECM. After reading about the symptoms and all my random electrical weirdness and randmom timing, I think that must be it. It ran like crap with the stock memcal, and it runs like crap with the new ultimate (actually, it doesnt really run at all). It fouls plugs like 2 minutes after I put them in. SUPER RICH condition going on. Black/grey (washed cyl. walls) smoke from the tailpipe like its a diesel. I know its not the FPR, I've fiddled with it every which way.

 

[berzerker]

Re: I have no clue... what the deal is.... Idle sucks.

where did the injectors come from / e-bay or ? just wondering if you got some oddball injectors or maybe even a low impendance injector.

 

[RSpengler]

Re: I have no clue... what the deal is.... Idle sucks.

50#ers are brand new, flow matched set from PTE.
-Rob

 

[SeattleSy#1255]

Re: I have no clue... what the deal is.... Idle sucks.

PTE are good...i'd check the ECM...it is somewhat rare, but it does happen.

tons of guys in CO and the springs area.

 

[sy2675]

Re: I have no clue... what the deal is.... Idle sucks.

Im not sure that this will be any help at all but here i go. My truck started having an idle/cold start issue and it kept getting worse. Truck was running real rich, replaced lots of parts, plugs, wires, cap rotor, o2 sens, thought inj was stuck had them cleaned, did vac leak test, everything seemed cool but the truck wouldnt idle and was a dog under 1500 rpms. The prob ended up being a small tear in the diaphram inside the FPR. The fuel pump was making plenty of pressure but under vac was sucking gas straight out of the top of the FPR into the intake( and everywhere the vac hoses went). Put an older FPR i had laying around on and the truck was back to new just like that. I found a post on here that mentioned the poss of this problem after hours of reading and wrenching. With the truck off, pressurize the fuel system by addeing a pos source the lead at the back of the intake/firewall. Do this with the vac line off of the FRP. If fuel comes out, you have a problem. Some are rebuildable. I am going to look for the kit to rebuild mine now. Anyone have any ideas where to look. Its a billet FPR but no name brand on it anywhere. Hopefully this reply helps someone, or at least narrows downn your search. :turbo:

 

[sattresyclone]

Re: I have no clue... what the deal is.... Idle sucks.

is your chip in upside down??