Bad Idle, no acceleration, Code44, bouncing boost?

[aaron97]

Well, where should i start... Hum... The boost guage fluctuates from boost/vacuum while at idle cruising but not under accelleration. Its been doing this ever since i got.
Couple weeks back i was driving around and the engine started to run very rough and when i tried to accelerate from the stop sign i had to nearly floor it to get it to move and the CEL came on. But it went away after a few seconds and the CEL went out. Havent had a problem since, untill yesterday. On the way to work, it started doing it again. Takes alot of throttle to keep it moving, CEL is on, and it feels like i'm trying to tow something. Trany seems like its holding the gears longer, and shifts 1-2 very hard. The turbo still goes full boost but its just not accelerating. Well, it is but very slow. I'm talking so slow that i can walk faster. But as long as i stay in the throttle and get it threw the gears i can cruise at 50mph with the gas 3/4 to floor, and thats how i got home.
I read the CEL and it gave a code 44. O2 Lean...?

Heres some of the stuff i've done over the past few months...
Fuel pump, Fuel Filter, O2 sensor, Radiator, Plugs & Wires, MSD 6a, MSD Coil, Cap&Rotor, Ign.Module, K&N Filter, and i pulled the trany 3 times in the past month for stupid reasons...

Any ideas? I've searched and couldnt find anything, and i looked over the engine for vac. leaks... I just dont know..

 

[NecroWolf]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

sounds similar to my problems and my problems have been injectors going bad.

 

[jjorgensen52]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

I just had this problem in my Sierra... was a bad MAP sensor, but that ought to be code 33 or 34 ... I'd check that

 

[QUICK STORM]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

do a compression test, whats your engine vacuum?

 

[aaron97]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

I just had this problem in my Sierra... was a bad MAP sensor, but that ought to be code 33 or 34 ... I'd check that

How do you "check" the MAP sensor? I looked and the plug and vacuum line is hooked up good, and i even went and bought a new MAP sensor from AutoZone, they gave me the wrong one or something, because the keyways dont line up and i cant connect the plug.

Here is what SportMachines site says about Code 44..
"Check the ECM wiring connections, particularly terminals 8 and 15. Check for vacuum leakage at the TBI base gasket, vacuum hoses or the intake manifold gasket. Replace the oxygen sensor."

I guess i will go look at the ECM cause thats the only thing i havent done, i dont think its the O2 sensor cause thats brand new.

 

[QUICK STORM]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

yes check the ecm to make sure the plugs are seated properly.

check the TB to make sure it isn't leaking, a fairly common vacuum leak. don't forget to perform a compression check on all cylinders, and check your engine vacuum so you know your engine is running good

 

[aaron97]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

yes check the ecm to make sure the plugs are seated properly.

check the TB to make sure it isn't leaking, a fairly common vacuum leak. don't forget to perform a compression check on all cylinders, and check your engine vacuum so you know your engine is running good

How do you check engine vacuum?

EDIT: Looking at my AutoMeter Boost gauge, it shows a solid -10psi at idle, while the stock boost gauge is moving from -5 to +5 at idle. When i rev it in park the stock gauge will show +10psi and the AutoMeter will move down to -15psi.

 

[aaron97]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

Well, i checked the ECM and changed the O2 sensor, still no change...

 

[NecroWolf]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

pull your plugs, see if any are fouled or if all are fouled and one looks new. when my first injector went bad five out of six plugs were fouled out and one looked brand new. now i am replacing another injector and this time that one plugs was fouled and the other looked lean. you might also put a multi-meter on all your injectors and see what the resistance is. they should all be close to the same i think it's 14.6 ish

 

[aaron97]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

Well, i just pulled all the plugs and did a compression check. All the plugs look the same and don't look that bad, they've only been in for about 1k miles and are gapped to .39 if i remember right. The compression was 140psi on all cylinders. I've also changed all the plug wires since i broke two of the MSD's. I pulled the cap & rotor and inspected that. The rotor was quit worn so i put a new one in. I suspect the MSD 6a and coil are the reason for wearing the rotor in about 1k miles. Changed the O2 sensor and checked the plugs and pins on the ECM. Still no change in idle.

When i say poor idle, its more of an extreme vibration. But at 1000rpm it smooths out, but it feels like the truck has no power at all. And i noticed last night when if its at idle and shaking around like it is, then when i turned the headlights on its idle dropped a little and the shaking/vibration got worse.

Another question, what is that black finned thing with vac.lines going to it, next to the MAP sensor? I noticed it gets very hot. That normal?

 

[QUICK STORM]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

check your battery and altenator. low output of both will cause the truck to not perform as well.

as far as your other concern, i'm not sure as i haven't looked under my trucks hood in a while. what about your knock sensor, maybe the sensor is seing to much knock and retarding the timing, do you have datamaster?

 

[jjorgensen52]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

my MAP sensor was actually clogged, but the only real way to check it is to replace it. Make sure the vac lines to it are in good shape. It helps control fueling, so if the pressure readings are wrong (which may explain your factory gauge being off I think the MAP sensor controls the gauge) it doesn't give the right fuel ... mine was so far off it was cutting the fuel entirely

EDIT: Now that i think about it, a bad MAP could trigger the 02 code as well due to screwed over fueling

 

[QUICK STORM]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

you check the ever familiar TB shaft leak?

 

[aaron97]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

you check the ever familiar TB shaft leak?

Are you referring to the gasket seal between the TB and Intake or somewhere else on the TB? I checked the gasket area as best i could, feeling and listening. If thats the gasket yall are referring to then maybe i can just go pick up a new gasket and replace it, i'm sure it cant cost too much..

I guess i will try to find somewhere to get a new MAP sensor, where do you guys get them? I tried Checkers and they don't even list them and AutoZone gave me one that the plug wouldn't plug into... it was also the same part number for '95 Yukon, so that makes me think their database just has the basic Jimmy MAP listed for Sy/Ty's. But that don't seem right to me, why would a N/A engine need a 2-bar MAP.. :squint: I could try PepBoys or a dealership.

Also, anyone know good local type store that carries 5/32 and 7/32 hose so i can replace all my vacuum lines? I tried all the auto parts stores and HomeDepot.. with no luck. Closest thing i found was an assortment of colored hoses commonly found in the import section at AutoZone. But its only 2' of each size...

 

[jjorgensen52]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

I got the MAP at the stealership ... paid an arm and a leg for it but I needed my daily back up and running... they show up on ebay occasionally

 

[aaron97]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

I got the MAP at the stealership ... paid an arm and a leg for it but I needed my daily back up and running... they show up on ebay occasionally

Well, I'm off to the parts store. I know the wrong MAP was $32, is the right one from a Dealer much more than that? I'd hate to spend "an arm and a leg" to get one and have it not fix my problem..

Going to try to find some vacuum hose and a TB gasket while I'm out.

One other thing... I was searching the forum again and came across a simular problem where the other person was getting 11psi vac. and someone said that was way low, but they never said what the vac. should be. I have 10-11psi vac. right now, so if that is way low then it would be obvious i have a leak somewhere, right? I never looked to see what the Vac. was before my problem so i dont know what it should be, i know on my turbo car its Vac. is usually around -25psi at idle.... Is that where the Ty should be?

 

[aaron97]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

Well, just finished replacing all the vacuum hoses. Every single one and the UPS guy showed up while i was in the middle of it and dropped off my new brake booster hose w/boost gauge hookup from RPM. Talk about good timing.. Found one of the TB bolts loose when i pressure checked the intake manifold. But even after all that work it didn't fix my problem... The vacuum is a little better now, its about -14psi instead of -10psi. and the stock boost gauge isn't erratic anymore.

I hate this truck... :rant:

Oh ya, where does everyone get their DataMaster thing i keep hearing about? I am curious about that knock idea... I wonder if some how my trany issues could be affecting the engine. Like is the trany is causing the vibrations somehow and the knock sensor sees and ECM is screwing things up because of it.... i dont know, i just reaching know...

Is there anyway or anywhere that can test any ECM to see if its good or bad?

 

[QUICK STORM]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

you want to see about -18 to 20psi of vacuum. if you get a real vacuum gauge and test it see what the vacuum gauge shows, ie what the needle does.

 

[aaron97]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

you want to see about -18 to 20psi of vacuum. if you get a real vacuum gauge and test it see what the vacuum gauge shows, ie what the needle does.

I'm using an AutoMeter gauge, is that not a real vacuum gauge or are you assuming i was just going off the stock gauge? Even if i am supposed to have more vac. than 14psi. i dont see where i could be losing it... I tested presurized the intake to 40psi. and use soapy water in a spray bottle to locate any leaks, and i used the ole rubber hose to the ear trick to see if i could hear any leaks around the intake manifold areas.

I guess tomorrows project is going to bust out the multimeter and start checking voltages. Hopefully that will turn up something. You know, i was just thinking... I just filled the tank with gas the night before, i wonder if all this headache could be the cause of some bad fuel. I put 91 in like always and from the same place as normal, maybe i should call some friends that use the same station and see if they've had any troubles. At this point, anything is worth a shot.

 

[QUICK STORM]

Re: Bad Idle, no acceleration, Code44, bouncing boost?

when you pressurize the intake. pull off the oil fill cap, and listen, pull out the dipstick and listen, go to the exhaust and listen. if you hear or feel air, then you have a LEAK.