I AM IN NEED OF SOME DIRE HELP!!!

[t3intercooled]

Just as the title says. I am in dire need of help. My scanmaster readings are not normal. Here is essentially what has occured up to this point. I am at a complete loss as to what to fix or where to look.

Car drove very well starting out this year. Then do to unforseen medical expenses I had to sell everything I could to cover monthly bills that were required (Gas, Electric, etc). Parts that I had on and sold are as follows:


Turbo Tweak chip and 80lb injector combo to be able to work with a UNMODIFIED stock computer.
Accufab 70mm throttle body and plenum with RJC power plate
Precision full ball bearing turbo
Angled IAC boss
Computer modded for injectors


Then I had my daily driver take a shit so I was forced to buy what I could to get the GN running. I wasn't looking for speed just reliability. Parts that I purchased to get it running are as follows:


Stock rebuilt Turbo
38lb injectors and turbo tweak 93 octane chip from jdpolzin
Mass air flow sensor
Stock Computer
Stock throttle body, plenum, & RJC powerplate
Brand New Walbro 340 from Full Throttle


Once I recieved those items I put everything in and the car ran good for 2 or 3 months. No detonation gauges read great. Just a blip of knock when it would shift but thats it. Then literally one day was idleing ok but then detonation occured when I was at a stop and began pressing the throttle the O2 readings would drop lean at first then if I eased it up to speed the O2 readings would be up at the 7-800s. That occured for a while but that was still my ownly vehicle. As long as I slowly eased up to the speed I would have the detonation.
I didn't change a single thing and while ideling in park, drive, reverse, etc. I noticed my O2 readings were 045, 075, etc. I know that the O2 readings are telling me its lean. As I said the chip, injectors, brand new full throttle walbro worked great for a while then literally the next day it started showing the lean readings. Now I haven't driven it since it began going wonky, so everything listed here is while it was parked running not driving so it wouldnt hurt the motor if it was lean. I began scrolling through the scanmaster and the volts were reading 12s and eventually dropped to 8s, so I figure being the pump is hotwired thats the reason for the leaan condition. Put a brand new alternator and to be safe a battery in and still same scanmaster readings.

I included videos of scanmaster reading, fuel preesure, and oil pressure. Im open to testing, checking, or replacing anything I need to. Being we have VERY knowledgable people on this board I figured this is the best place to start. Thank you to everyone who assists, it is GREATLY appreciated!

 

[TurboBuRick]

Mmmmmm, broken rocker shaft? Pull the valve covers.

RL

 

[mearly65]

Your TPS is low. Should be around .46 with car idling not .42. Your IAC's are way high. Should be between 15-40 not the high 70's. Also l noticed that your cc's never moved off 36. Could be you have a bad O2 sensor?

 

[t3intercooled]

Rocker shaft??? That can cause a lean condition? See that's why I post here....I wouldn't have ever thought a rocker shaft could be the culprit. I will check that today.

I have the stock 02 sensor, and the wideband. I don't know of a way to test the stock and wideband O2 sensors. Besides just replacing is there a way to test them? I will raise the throttle position and try that as well. Only reason its at .42 is cause my prior max effort mafless and turbo tweak chips in a modded computer (modded for injectors) called for TPS of .42. Now the IACs being high can that be caused by a low or faulty TPS sensor? Also side note just to verify, IACs is the position of the throttle blade, is that right? Lastly besides simply replacing the TPS sensor is there a way to test it? Like either taking a meter and seeing what ohms, resistance, etc. it has? If so what should the reading be.

Lastly the pic that's at the bottom in this post is the reading of my mechanical fuel pressure gauge with the line off.

 

[pacecarta]

Your TPS is low. Should be around .46 with car idling not .42. Your IAC's are way high. Should be between 15-40 not the high 70's. Also l noticed that your cc's never moved off 36. Could be you have a bad O2 sensor?

um .42 is fine.... and he has a TT chip , cc wont move at idle as its an openloop idle chip

 

[Amelio]

definitely pull your rocker covers and verify the shafts are not broken....the car does not sound like it is hitting on all 6........also your O2's are a lil wack and not moving as fast as they should be so the O2 sensor is suspect but before you through that at it you need to verify your rocker shafts.

Also I saw in your post you say you did replave your battery correct and alternator? If so you have a charging issue your sm showed 12 volts wile it was ideling it should be reading 13.5-13.9 or better. You need to also first address yor charging system before you throw parts at it.

A weak charging system will cause all kinds of problems....I would styart there.

 

[t3intercooled]

Ok, going to pull the valve covers now. Yes I changed the battery and alternator. What is everything I should check within the charging system besides the battery and alternator

 

[t3intercooled]

I'm not 100% sure how everything scanmaster wise etc ties in. So if someone wants me to make a specific video of anything or of any readings that would help just let me know. I'm willing to do and test or try anything

 

[Timbuick]

have you checked the MAF readings as you accelerate? Should rise quickly as you accelerate and be at 255 if the throttle is fully depressed?
if the car has suddenly gone wonky the MAF may be the culprit.

 

[Amelio]

I know the batt and alternator is new but act like its not and start your search. Check voltage at the batt car off...should be right around 12 volt +or- a .5 volt Then check voltage at key places such as the back of the alternator and starter should be roughly the same. Then check all your grounds. The main one under the turbo on the front pass side head....it can wiggle loose just a little and cause problems. Also good to check all other grounds but focusing on the mains because your charging system is not working right. I am sure if you do a search on this board you will find posts that tell you where all the grounds are...there is also a group on the back side of the pass head known to have issues.

Once you have done that start the car check the voltage at the batt and the alternator again and any where else you checked before the car was running. (also check at the fuel pump car on and off) the voltage should in crease 1.5-2.0 volts with the car running. If it is then there is possibly a problem in your DLC or scan master.

Post your findings after you test these few simple items.

You very well may have more than one issue but the biggest from what I see is your voltage. You need to determine if the voltage is really that low or if its a sm issue. If the voltage is really that low you need to fix that issue first! Low voltage on these cars can cause all kinds of issues.

 

[t3intercooled]

Well I found an issue. My question is could this issue be the single culprit causing the voltage to be off and everything? Also can I buy just the rocker or do I have to buy a whole shaft?

 

[Amelio]

I'm not 100% sure how everything scanmaster wise etc ties in. So if someone wants me to make a specific video of anything or of any readings that would help just let me know. I'm willing to do and test or try anything

Sm readings are very important but first you need to verify proper voltage.......all other things can be tested and verified once you determine you have proper voltage.

I stress this because I have delt with the exact same problem....The car would start and run just not run good...It did not hit me at first about a voltage issue because the car would start and run.

Also I beleive it may be on Turbo Tweaks site I could be wrong.... there is a list of all the sm readings what they are and where they should be.

If not there it is definitely on this site somewhere that has been covered many times. Maybe another member will see this and post a link.. If not just post another thread asking for a link to sm info someone will surely have it.

 

[Amelio]

Well I found an issue. My question is could this issue be the single culprit causing the voltage to be off and everything? Also can I buy just the rocker or do I have to buy a whole shaft?

View attachment 167599

been there done that.......

Good you found a problem that is your rough run issue for sure and it will cause inproper mv reading but not low voltage reading.

Yes you can get rockers and shafts seperately...check the forsale boards.......I think I have spare rockers but I know I do not have any shafts.

 

[Amelio]

where do you live?

 

[captflash]

Cotton's Performance has these




Product ID: RSA
Stock Rocker Shaft Assembly
Details

This is a SINGLE used stock rocker shaft assembly. We have LOTS of these on the shelf so note how many wanted when ordering.

Price: $20.00

 

[t3intercooled]

where do you live?

Minnesota

 

[whitehot1]

You can buy replacement rocker arms from the auto parts stores,and you can get just one if thats what you want.I would question the condition of the other rocker arms though. The last time i bought stock type rocker arms they were around $3.50 each at Autozone but thats been around 10 years ago.

Just did a quick check at the auto parts stores. Autozone has the best prices for the rocker arm sets: set includes the rocker arm and the retainer button. The rocker arms are labeled L for left and R for right. The R rocker arms are $3.79 each and the L rocker arms are $4.99 each. They are not available in my local store and are special order only. These prices are even better than Rockauto sells them for.

 

[t3intercooled]

The broken rocker can cause detonation too...am I correct?

Also what causes that to happen to the rocker? Like should I replace the lifters or cam or are the rockers just that weak?

 

[whitehot1]

The broken rocker can cause detonation too...am I correct?

Also what causes that to happen to the rocker? Like should I replace the lifters or cam or are the rockers just that weak?

I've never broken a rocker arm but i have broken the rocker arm shaft before. I would suggest replacing the rocker arms and shafts and you should be good to go,unless you have an issue with the lifters. If you don't have an issue with the cam and lifters i would leave them alone.

 

[t3intercooled]

I've never broken a rocker arm but i have broken the rocker arm shaft before. I would suggest replacing the rocker arms and shafts and you should be good to go,unless you have an issue with the lifters. If you don't have an issue with the cam and lifters i would leave them alone.

Now I apologize for asking so many questions, I just want to make sure I do this right.

Besides pulling the cam and lifters out is there a way to inspect them? Also depending on if there's an issue I don't get roller valve trains. I have stock irons with a 12hr port and polish. My question is what can I get and what would need to be modded to make it roller? I am very unfamiliar with what exactly describes roller valve trains. I've heard people say hydraulic roller and solid roller. What's the difference and what if either would work with my motor? Basics of my motor is bored .030, stock crank, TA non roller camshaft (I have specs of cam if they would help), stock rods, forged pistons, iron heads with port work. I plan on going aluminum heads in the future, and a stroked shortblock from webber performance. But that won't be for a few years minimum. So say I wanna do cam, lifters, and rockers, what type if any roller items would work with my iron headed motor and what if any machining would have to be done? As I said I apologize in advance for all the questions, I just want to make sure I do this right.