2018 ZL1 1LE with Texas Speed Cutom Cam acts like O2 sensor problem but wont idle now

[Jabercrombie]

I just put a TS cam in and built the motor it already had headers and a interchiller with 9.17 lower pulley and 2.5 upper run on 93 and E but I am down to 15% E now trying to make sure I did not have bad gas. I pumped out 5 gallons but it all looked good and I used the aux pump to pump it out so I have not tested my intank pump but my pressure seems to be good. Aux pump is a DSX can bus and comes on at 500 KPA commanded pressure. When I put the engine back in it ran great for about 30 miles and I bumped up the rpm to 5k when after the pull about 1/4 mile down the road it goes dead. I tried to crank it up but it was like the engine was locked up. I waited about 30 seconds and it fired rright off and ran fine . I replaced the batterry with a new one thinking it was bad but the next time I ran it up to 5k rpm it did the same thing again and locked up also. but after this time it did crank back up and run but now it wont idle right like its misfireing on a cylinder. I pulled the valve covers but did not see any problems., I would like for someone to look at the scan of when it shut off on me and see if anyone can see a problem that would cause this . Maybe someone that can read the tune better than me could find the problem right away. I sure would love for someone to find the problem as its run me crazy for 2 weeks now. I will post the tune and the scan so maybe someone can help me out. On the scan at 7:44:734 is when it went dead but you would only know it by the rpm going to zero.
Thanks

[GHuggins]

I haven't looked at the log or tune - just a couple of questions as this doesn't sound good in the write up. Did you install the LT4 valve springs - yes there are some specific. Is it known that this cam will work with this engine? Were the correct lash caps used? Was pushrod length checked? Almost sounds like a valve is bent and sticking shut with the first run and now she's really tweaked and misfiring - but that's going from what you're describing...


Edit - just checked the log - you do have some nasty lean spikes happening on the wideband with cylinder firing from the looks of it. Recommend either watching misfires at idle or doing a compression check before running it anymore.

[Jabercrombie]

Thanks for taking a look at it for me, I did put the lash caps back on all the intake valves and it has the double springs in it but I did not put the heavy wall pushrods back as I had before due to the fact that I bent valves last time with those but it did not bend the push rods so I may have bent a push rod. I am going to pull them tomarrow to check them out. The last time I bent all 8 intake valves but the cam sprocket broke and put the timing out 180. I did a compression check and they all passed but yet they were still bent. I pulled the supercharger off and could see the intake valves and they were all seated so thats why I want to check the pushrods. If I have a bent push rod then I will pull the head as one of the heads is brand new. If I find another bend one I am putting the stock cam back in this car.
Thanks for the help as now I think you are right about it being valve train problems as why would it run great for 2 weeks then now wont idle, I just hope it is only a push rod and the valves are good as they are brand new.

[GHuggins]

If a valve got tweaked - and I do mean "tweaked ever so slightly" during assembly then there's a good possibility that it got hot and then stuck open and kissed. Only ever seen one guy do that. He worked in the shop across from me and he managed to "tweak" one apparently rubbing it with the socket while torquing the head bolts down. If this engine has already done this once - was the cause of the first time ever discovered? Really sounds like "this" cam isn't designed for this motor or is being run as a variable cam when it's not supposed to be - in fact this sounds like possibly the more likely key part... There are only a few "cams" out there that still are variable use for these motors. Then if it did that much damage the first time, who's to say the cam didn't get tweaked and twisted too? They are just hollow metal tubes.

Another guy on here installed a lt5 cam in his and I think he's happy with it - if you wanted to go back that route.

[Jabercrombie]

The cam before was the reason it took out the valvetrain as it broke so this is a new cam and Texas Speed calculated it so it should be fine, I am thinking that the push rods were my weak link as before I had the thick wall ones and I wanted the push rods to bend before they damaged my valves to the point of breaking.The push rods were a bit stronger than stock but I think they were .80 wall and the other set I had was a 1.25 wall. I hopoe its simple as it runs good over 1500rpm Oh yea I put the LME vvt delete sproket and new front cover on so it has no vvt anymore just a new sproket that fixes the 7 degrree timing problem that the vvt had built in it. That piece was nice as it had o-rings so no more RTV mess,

[Clutch]

You've got a bad TPS. Look at it. It's jumping around like someone's smashing the gas pedal over and over.
You owe me a beer...

[Jabercrombie]

Thought that also but I can learn the throttle and it goes where I tell it to go and holds the position. I think that my #3 intake valve is not oppening all the way due to a bent push rod but should be able to tell you in a few hours.

[Clutch]

No it doesn't! Look at your scan after it shuts down on you. I can clearly see you push the pedal to the floor (99.6% Accel. pedal position) your (TPS only goes to 43.1%) and guess where your Throttle position is.....hint (IT'S ONLY AT 43.1%!!!) That shi#t is broke!!! Replace it before tearing your motor apart.

I mean you did come on here for help didn't ya.

[Alvin]

I just put a TS cam in and built the motor it already had headers and a interchiller with 9.17 lower pulley and 2.5 upper run on 93 and E but I am down to 15% E now trying to make sure I did not have bad gas. I pumped out 5 gallons but it all looked good and I used the aux pump to pump it out so I have not tested my intank pump but my pressure seems to be good. Aux pump is a DSX can bus and comes on at 500 KPA commanded pressure. When I put the engine back in it ran great for about 30 miles and I bumped up the rpm to 5k when after the pull about 1/4 mile down the road it goes dead. I tried to crank it up but it was like the engine was locked up. I waited about 30 seconds and it fired rright off and ran fine . I replaced the batterry with a new one thinking it was bad but the next time I ran it up to 5k rpm it did the same thing again and locked up also. but after this time it did crank back up and run but now it wont idle right like its misfireing on a cylinder. I pulled the valve covers but did not see any problems., I would like for someone to look at the scan of when it shut off on me and see if anyone can see a problem that would cause this . Maybe someone that can read the tune better than me could find the problem right away. I sure would love for someone to find the problem as its run me crazy for 2 weeks now. I will post the tune and the scan so maybe someone can help me out. On the scan at 7:44:734 is when it went dead but you would only know it by the rpm going to zero.
Thanks

The frame rate of this log was really slow.. Were you trying to use standalone datalogging? Might be better to turn off a few pids to get it faster.

The lift fuel pressure is a bit wild. I saw it fluctuate between 88 and 40 lbs on one pull. I'm not a fan of these unregulated AUX pump kits for this reason.

In fact when the thing stalls in the middle of the log it is right after this huge pressure spike/fluctuation that we might not be able to see the actual peaks because of the frame rate. It looks after it does this on a spirited pull it never recovers itself.

Feeding 85+ psi in a PFI fuel injector will cause it to lock up.. I have no idea what high pressure feed will do to the high pressure pump

[GHuggins]

No it doesn't! Look at your scan after it shuts down on you. I can clearly see you push the pedal to the floor (99.6% Accel. pedal position) your (TPS only goes to 43.1%) and guess where your Throttle position is.....hint (IT'S ONLY AT 43.1%!!!) That shi#t is broke!!! Replace it before tearing your motor apart.

I mean you did come on here for help didn't ya.

This is normal genV behavior. They'll only open the throttle fully when conditions are right. It may have limited it for many reasons including but not limited to the fact that it saw something wrong in it's data.

I've had ZL's running these fuel systems that were hitting 80ish psi that handled the pressure on the high pressure fuel pumps without issue. Doesn't mean this one can't have a problem. I just keep remembering the wideband appearing to catch a misfire when I glanced at the log...

Did you find anything with the pushrods or valves?

[Alvin]

This is normal genV behavior. They'll only open the throttle fully when conditions are right. It may have limited it for many reasons including but not limited to the fact that it saw something wrong in it's data.

I've had ZL's running these fuel systems that were hitting 80ish psi that handled the pressure on the high pressure fuel pumps without issue. Doesn't mean this one can't have a problem. I just keep remembering the wideband appearing to catch a misfire when I glanced at the log...

Did you find anything with the pushrods or valves?

It could be higher than 80's considering how slow the frame rate is on it.

[GHuggins]

Usually the check valve and orifice going into the pump won't flow enough to lock it - in fact I've never seen one lock or blow - guess it's possible as it happens to diesels - the rails usually deplete it before the pump can keep up. It will most likely damage the check valve trying to shove that much through it as the OE is small and cheap. If he's going to run this type of pump system he really needs to upgrade it to the lingenfelter. There is another company out there that makes an upgraded valve - in fact lingenfelter may even re-badge this as I don't know, but the hpfp usually won't allow but so much into it regardless. I've got one guy right now that's running 2 supply lines to the valve and then one to the hpfp - just for ethanol. He also found a unique E sensor that has 2 lines going to and out of it - it crosses kind of like an xpipe internally for accurate E reading - first time I had seen that - he's the one I was recently seeing 80psi on - think the highest was 83, but I don't remember exactly... You can usually throw a lot of fuel at these, but the simple fact is the hpfp's can only flow so much and eventually require upgrading - which apparently has gotten VERY expensive. Think he told me they were around 6000 now just for the pump :O Weren't they in the 2000ish range not long ago?

[Clutch]

@GHuggins - Are you saying that even with the engine "not running" that the same applies?

[GHuggins]

Depends if a code or something has already set. I don't jump to judgement with anything on these things anymore as parts have gotten very expensive. If the throttle was losing all voltage it should set codes for it and then either not crank at all or just idle when it does crank. It is possible to have a loose connection somewhere. Seen lots and I do mean LOTS of fuse block and ecm connector issues with these cars.

[Clutch]

I noticed two torque peaks before shutdown. Driver demand set at 550 lb ft but torque peaks in scan were 773 and 784 lb ft.

Maybe that could cause things to get bendy?

[Jabercrombie]

I pulled the valve train and checked the push rods and all were fine so I increased my idle to about 950 and she was running fine till today when now I cant go over 1500 rpm again without drropping fuel flow and its like the injectors are cutting fuel to the engine but the log is crazy as when I lose flow sometimes the injectors are off and sometimes there on, I saw on the shut down log that the throttle was closing due to torq but now I think that I have either a clogged fuel line or a HPFP going out but I am not sure. When it calls for 1400 psi at .27 cylinder airmass at 1800rpm it was only at 670 psi and the low side was at commanded sp. I am putting anotherr log that shows the flow go to zero several times above 1600rpm maybe you can see something I am missing. If I have to take the fuel tank out I will be upgrading the low side to a rreturn style system.
Thanks.

[GHuggins]

I think you're just seeing the delay in build or the wrong log is posted because I don't see that anywhere in it. It's not ideal, but rail pressure does build. In the meantime it shows 39% lean and multiple misfires, but that may be right where you're letting off the throttle for the lean part. Cylinder leak or cylinder to cylinder compression will show more. The last time you ran it and got into boost - was it sputtering any? You've still got the map/baro and iat codes set too.

[Jabercrombie]

The last time I did a pulkl it was fine till about a 1/4 mile down the road.Attachment 131943
take a look at the pdf and see the line as its in the bottom grraph and the FF is fuel flow which is zero and it does this as long as I put the accel over say 1500 rpm its like when I put a set of 60 lb injectors inm it that were sold to me a few years back as it will act like its hitting rev limiter at 1500 rrpm.

[Jabercrombie]

On the codes that are set they are permanent codes and do not show up on the cluster but I can not reset them either. not sure why they show up as permanent

[Jabercrombie]

Well I went ahead and got a new ECM due to the fact the injectors were staying on or at least 5 of 8 would stay on when they should be off and that is what fixed it. No more problems with the 1500 rpm shutoff either. You never know abouit the ECM.