Well i got the new engine in this week end, and it has literally all new sensors, all new TPS and IAC, even IAT because it seemed to do it more in the cold weather but that did nothing, you name it and it still does the same thing as the other 2 engines (both being stock) and this one is all built up brand new.
Now it did start when i put on my Spec aluminum fly wheel a long time ago so I have always blamed it on it being that there is a lot less rotating mass, so if there is any kind of hicup or miss it just dies where the stock fly wheel would have been able to carry it threw it.. but could this be caused by a week spark? I have tried every thing guys. Heated 02 sensor which is about 4inches from the turbo, checked all the spark plug gaps, only part i have missed is the ignition, but I would hate to buy a MSD box and still have this problem..
Now i know this might not be exactly the right forum but it seems to only be a problem once guys go boosted. Any one have any other ideas? Like could my tune be a bit to rich (i did forget to check that when i had HP tuners hooked up)? Because it will idle nicely at times but other times it wont, also some times when i go to start it, it will studder and stay and like 200rpm and i have to give it gas to bring it alive.
Also I dont get any check engine lights and i have hooked up my buddies HP tuners to it and drove around and couldn't find any thing.
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
let me ask about your gas and where you got it from are you sure its good. There are Gas stations that water down gas. there a stations that mislabel it also. I recently have been a victim of bad gas. its happened to me before more then once.
I get it tuned with 91 Esso gas (so on road trips i don't have to worry about hunting down 94) but mainly run 94 Mohawk gas (here in canada) And even when i do get gas at other stations is still has done the same thing. I put the aluminum flywheel on in October 2005 and its been doing it ever since then so it obviously has to do with that but im just wondering what I could do to fix this. As i have all light weight rotating parts right now (every thing you can get any way) and it revs up and down so fast compared to my stock Jbody, And the throttle response is insanely quick, so I would really hate if i have to get rid of it
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
carnivorous mouse wrote:let me ask about your gas and where you got it from are you sure its good. There are Gas stations that water down gas. there a stations that mislabel it also. I recently have been a victim of bad gas. its happened to me before more then once.
There is not a single gas station out there that "waters down" gas. In fact they have very expensive monitoring systems to alert them of the water content in the gas. I do not think it is your spark. It sounds to me like your IAC moter is not responding fast enough. I think this was a problem gm created by not programming the ecu to make it start responding sooner so replacing it will not help much if the problem is that it is being told to move to late.
Edited 1 time(s). Last edited Monday, May 26, 2008 8:46 PM
FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!
Maybe I'm not up to date with every bit of automotive lingo, but what the hell is "hunting"?
Um, I would recomend putting this on a Sun machine, or something similar. It will tell you if the spark you are generating is weak or not.
I would not just go throwing parts at it until you have it properly diagnosed.
John Benham wrote:Um, I would recomend putting this on a Sun machine, or something similar. It will tell you if the spark you are generating is weak or not.
I would not just go throwing parts at it until you have it properly diagnosed.
Im done throwing parts at it.. and even the parts i did throw at it were going on regardless as i wanted it litteraly to be a fresh new motor with all new sensors so they were going to be put on any way.But yea maybe ill wait till after my retune and see what it its like
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
Wade Jarvis wrote:There is not a single gas station out there that "waters down" gas.
I know for a FACT that the stations on the reservation near Buffalo do it. And I've heard rumors of other local stations doing it, but I cant confirm those for sure
Cant water down gas. Even if it was, most likely the engine wouldnt run well and it would kill the injectors. End of story.
Ok, I have almost the same idle problem. Now you could try and go with MSD coils. They wont really help in power BUT they can help out at an idle with its multi sparks. Also, advance your timing at an idle by 1 degree, but not over a max of 17. See if that helps.
Do you have AC Delco double Platnuim plugs with AC Delco plug wires?? I would reccomend switching to thouse considering its been know to cause idling problems if you use other brands. You could even go to a step colder plug, but stay with the AC Delco double plats.
Let me know if that worked out at all for you.
----------------------------------------------------------------
www.bradsairsoft.com
CheesyPackerFan wrote:Cant water down gas. Even if it was, most likely the engine wouldnt run well and it would kill the injectors. End of story.
Ok, I have almost the same idle problem. Now you could try and go with MSD coils. They wont really help in power BUT they can help out at an idle with its multi sparks. Also, advance your timing at an idle by 1 degree, but not over a max of 17. See if that helps.
Do you have AC Delco double Platnuim plugs with AC Delco plug wires?? I would reccomend switching to thouse considering its been know to cause idling problems if you use other brands. You could even go to a step colder plug, but stay with the AC Delco double plats.
Let me know if that worked out at all for you.
Well i was going to go with the MSD box but i really dont think thats what it is now. As for spark plugs I am using NKG Iridium IX. And i dont have plug wires... 2.4L....
But i may try going back to AC Delco as i need some new ones any way, just the guy that tunes my car was the one that put the NGK plugs in.
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
OH, lol my bad on the plug wires, im a 2200 guy. Its habbit. I have heard NGKs are fine but id rather stick to the AC Delcos
I just know my car seems like it has a small miss at an idle. It runs good sometimes and then others it has the miss. I use e85 also, but it did it while on premium. Anyway, just making some suggestions... post up what happens.
----------------------------------------------------------------
www.bradsairsoft.com
Josh I think I know what your problem is, That motor will only run correctly in Florida, so just ship it all down to me
.
Hope ya get it fixed man. Good luck.
Car is for Sale!Supercharger kit is for sale!
Bobby(Blown&Pullied) wrote:Josh I think I know what your problem is, That motor will only run correctly in Florida, so just ship it all down to me .
Hope ya get it fixed man. Good luck.
ahaha well you may be half right... it does tent to run a bit better in the warm weather... not great but better then when it was -35 here ahaha..
And like I have said I would hate if i have to go back to the stock flywheel ahah. Because I can not even describe how stupidly fast and easy this engine spins up now with the Aluminum flywheel, aluminum crank pulley, lighter pistons and rods and with the all new timing chain set up (with absolutely no slack in the chain now) throttle response is deadly.. and it is probably because I am not going quite as hard on it being a new engine but I am getting much better gas mileage now
400kms with the stock engines in the city to 475-500kms now in the city
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
I'm not boosted on my 01 Z24 but have flywheel and underdrive pulley and no issues. My boosted auto has not issues idleing, but it has a heavier flex plate than stock, and the 2.3 underdrive pulley.
FU Tuning
I would NOT put Delco Plats in your engine......Platnum doesnt seem to mix well with boost....
I have heard of other people that had the lightened flywheel and pulley, and the car would rev to fast for the stock computer to keep up. Whether thats what is going on or not....I cant tell you. I would really recomend a Sun machine, it should be able to pin point your troubles. (if you have someone capapble of using it and understanding it properly).
I use the plats with no problems at all under boost. I recomend a colder plug than stock though.
If the engine is missing at an idle, you will feel it stumble more with a lighter flywheel. But a lighter flywheel will not cause it to stumble that bad as you describe. Its true, the whole flywheel helps carry the engine through firing of the cylinders but you shouldnt have a problem if all your cylinders are firing the way they should.
I still point to spark. Either upgrade to better w\ multi strike at idle or do a tune up and see if that solves your problem.
----------------------------------------------------------------
www.bradsairsoft.com
John Higgins wrote:I'm not boosted on my 01 Z24 but have flywheel and underdrive pulley and no issues. My boosted auto has not issues idleing, but it has a heavier flex plate than stock, and the 2.3 underdrive pulley.
humm... how did you get a heavier flex plate? what company did you go with?
CheesyPackerFan wrote:I use the plats with no problems at all under boost. I recomend a colder plug than stock though.
If the engine is missing at an idle, you will feel it stumble more with a lighter flywheel. But a lighter flywheel will not cause it to stumble that bad as you describe. Its true, the whole flywheel helps carry the engine through firing of the cylinders but you shouldnt have a problem if all your cylinders are firing the way they should.
I still point to spark. Either upgrade to better w\ multi strike at idle or do a tune up and see if that solves your problem.
Yea i have colder then stock i do believe. Now I can pick up a MSD box for the increased spark but i would hate to get it and still have this problem
And as for a tune, it has had this problem with 3 different engines and 3 different tunes (well re tunes)
I did notice today thought when i have the A/C on it will not die and wont hunt at all? ahah i mean this is sweet as a temp. fix but i dont want to have to only drive the car with the A/C on lol but i cant figure out why more load on the engine fixes it?
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
could it have anything to do with vacuum?
my car does this sometimes also, but i have a built HO motor (N/A).
Check all of your main grounds on the engine, chassis, frame, etc... It sounds to me a lot like a grounding issue. Perhaps add a few more grounds from the engine to chassis, will help no matter what.
To check that the problem isn't your coil pack(s), what you need to do is remove the coil pack and check the resistance in ohms between the secondary terminals. The resistance should be damn near 10,000 ohms. If it's not, then you have a bad coil pack.
I would try a cylinder drop test as well just to see if you can isolate things to a particular cylinder.
You can also check your ECT sensor for correct operation by referring to
THIS chart and match the resistance to the temp.
Also, check out
THIS page and refer back to it to help you out through your diagnoses of issues!
Jason
86svo wrote:Check all of your main grounds on the engine, chassis, frame, etc... It sounds to me a lot like a grounding issue. Perhaps add a few more grounds from the engine to chassis, will help no matter what.
To check that the problem isn't your coil pack(s), what you need to do is remove the coil pack and check the resistance in ohms between the secondary terminals. The resistance should be damn near 10,000 ohms. If it's not, then you have a bad coil pack.
I would try a cylinder drop test as well just to see if you can isolate things to a particular cylinder.
You can also check your ECT sensor for correct operation by referring to THIS chart and match the resistance to the temp.
Also, check out THIS page and refer back to it to help you out through your diagnoses of issues!
Jason
thank you very much for this... I defiantly will go threw all of the above this week and see if i can narrow it down... I was at one point wondering if it was a grounding issue, so when I put this new engine in a few weeks ago I made sure every thing was grounded tight and properly and where it was grounded I made sure it was bare metal (no paint or rust around the contact patch) but I do know people have fixed a lot of problems just by getting a grounding kit and installing that.
Now as far as a cylinder drop test goes. I can try it, but it will be a lot harder to accurately see the difference between each on as i will have to turn the car off and on for each cylinder being that I still have the IDI cover and it would be hard to do with out turning it on and off as I would have to pull the cover off each time.
The coil packs I am pretty sure are ok/not the cause of it. As I have a few spare ones laying around and I have tried a few of them and the same issue still was present.
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
Wait, with the AC ON it doenst hunt or die???? Is the AC clutch fully disengaging when you turn it off. If the clutch is catching it could cause it to hunt and die since the engine isnt prepared for it. I dunno. But that is weird...
----------------------------------------------------------------
www.bradsairsoft.com
it will still hunt a bit and still does die with the AC on.. but not as much and it doesnt hunt as crazy... with out the AC on it goes from about 200rpm and bounces up to about 2000rpm...
with the AC on it goes from about 600rpm to 1100rpm
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
Have you tried swapping in another PCM/ECU?? Quite possible the computer could have bit it.
Check your high pressure a/c binary switch wiring. The wiring is too short from the factory causing the pins to pull and make the car idle low and/or die. There is a TSB out about it.
86svo wrote:Have you tried swapping in another PCM/ECU?? Quite possible the computer could have bit it.
not yet.. I do have another spare one which i may try. Just I am wondering, I have my tune saved on HP tuners, but if i flash it over to my other PCM wont that bring any problems from the last computer over to the new one?
BlackRL wrote:Check your high pressure a/c binary switch wiring. The wiring is too short from the factory causing the pins to pull and make the car idle low and/or die. There is a TSB out about it.
Thank you, ill check that out tonight. but the car doesn't idle low at all.. i have actually changed it with HP tuners and even raised it up to 1000rpm for idle
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
