DaBwyan61

Hello! I just wanted to get a thread going on the current state of my camaro and some questions I had regarding some of the things we are still trying to diagnose. I bought the car back in May with around 89.5k miles.

Things the car came with:

6-speed Hurst Shifter
(Full?) Flowmaster exhaust (cat is gone and headers don't seem to look stock)
K&N Intake (not sure exactly which one)
BF Goodrich 245/50ZR16's all around on (stock?) chrome wheels. Seller also threw in 10-spoke wheels which I think are off a slightly newer 4th gen
3.42 rear end (GU6 code)
And that's about it. The rest of it is pretty barebones, including crank windows (which didn't bother me as I've heard the power windows can break easy)

Things we've done since getting the car roughly in chronological order:
Oil/Filter change @ 90k mark
Tire alignment
New fuel filter
New spark plugs for cylinders 1-6, stopped there as the older plugs seemed to look fine and 7 & 8 are definitely not easy to get to (any advice/tricks on how to do 7 & 8 would be greatly appreciated)
New timing belt (belt was a different size than what Autozone had in its database, will find receipt and update size)
New water pump
New optispark (Definitely helped me learn about the car and wrenching)

Things I have questions on / some ideas of:

1. ABS INOP / Low Trac lights
When you first start up the car and get moving the brakes feel a little funny and the low trac light will come on. It feels like it is coming from the front left brake. I did manage to pull the ABS codes from the inop light and what they are and what the service manual says (with manual reference page #s):

ABS DTC Code Table: https://drive.google.com/open?id=0B9...Vg2NmtIMDdYems

28: Rear Excessive Wheel Speed Variation 5E1-62 https://drive.google.com/open?id=0B9...2k0U20tME9EZms
32: LF Wheel Speed Snr Ckt Open or Short to G nd/Batt ( 1 of 3) 5E1-64 https://drive.google.com/open?id=0B9...E1fYUpBSnF2R2M
33: RF Wheel Speed Snr Ckt Open or Short to Gnd/Batt (1 of 3) 5E1-70 https://drive.google.com/open?id=0B9...2VtZjZOZnVOZ3M
16: ABS Enable Relay Coil Circuit Open 5E1-46 https://drive.google.com/open?id=0B9...DM2U3k3b2s5d2M
58: Left Front ABS Motor Circuit Shorted to Batt 5E1-124 https://drive.google.com/open?id=0B9...zd4LXhFR29GNTg

I'll read more into the manual to see what each says, but if anyone knows anything about these any extra info would be appreciated. At first I thought it was just the front left ABS wheel speed sensor but having a second look at the codes I think it may be a little more than that.

2. Some stuttering while on throttle
Sometimes with some light throttle, or the car being in 6th, or if the engine is under a little bit more load (?) like going up a hill the car seems to stutter. I've heard some people suggest fuel filter (replaced already), and other say plugs/wires may be a possibility (could be, 7 & 8 plugs not changed yet and no wires have been changed). I also had the idea of a bad MAF sensor or a bad throttle cable, but I think those are less likely and I may not know enough about those yet to accurately guess.

3. Driveshaft shaking/vibrating
Easy to tell when in 6th on the highway, but once you start doing 70-ish+ it sometimes feels like the driveshaft or something will shake loose (to go along with the stutters). There's also quite a bit of vibration you can feel if you put your foot on the clutch pedal and push a little. The vibration I'm fairly certain is a U-Joint but I'm not sure about the shaking or if the shaking goes along with the stutters.

4. Rear end whine
Sound really comes out when you're in 5th & 6th. I don't think I should be too worried about this as I think it's the gears. Our trusted mechanic suggested trunnion gear (or maybe pinion?)

5. Strange idle behavior?
I'm not sure if this is a V8/LT1 thing but when idling the engine kind of has a wave-like behavior where the revs fluctuate 100-150rpm or so. Again, not sure if it is a real issue or not, just something I've noticed.

6. Bad start up every once in a while
Every once in a while the engine doesn't seem to want to start and will stall, and then if you try again it doesn't really want to turn over. After removing the key, waiting a few seconds, and trying to start it again it usually works. Usually does not happen if engine is cold but still possible. More likely to happen when the engine is warm. Not sure if it's a sign of a future problem or what, maybe related to the plug wires again.

7. Steering usually pulls to the left, sometimes right
The car has in fact had an alignment recently. That seemed to make the problem a little less apparent than it first was, however you can still feel it slightly pull to the left if you're on the highway. In some places it may try to pull to the right. There's a certain stretch of road in our town where if you drive along it you can feel in the steering wheel that the car is shifting from pulling either to the left or right and the steering will feel somewhat loose. Have not looked too much into this problem yet, but will be something I will research mire

8. Fluid leak, probably oil
I just noticed it for sure this morning as I left for work so I have not had too much time to get to the bottom of it. I thought I had seen something in the driveway yesterday so I parked differently to try and confirm it was leaking. We had the car get an oil change right about at the 90k mark, so within a week or two of getting it. Car currently sits at a little bit below 92k.

Those are basically the main issues I'm working on right now. There are smaller issues such as the speedo being off by around 5-7mph (not a huge deal, but it makes me wonder since the tire size on the sticker on the door says 235, not the 245's that are on it now) and the gas gauge also being off (also not a huge issue, car regularly averages 18mpg and can easily calculate how much has been used in 15.5 gallon tank). Once those are sorted out I'd love to change a few things around on the car. I'll add them here and would love any suggestions and advice.

Possible Future Mods:

LT1 LE2 (still slightly confused on what it all consists of, any simple explanation and some advice for supporting mods would be greatly appreciated) http://elliottsportworks.com/?page_id=53
How accurate is Zigroid's comment on supporting mods today? This thread is a decade old: https://www.camaroz28.com/forums/lt1...p-mods-457827/
3.73 rear end-->4.10 rear end (always see this recommended, not sure where to find it to buy)
Subframe Connectors https://www.summitracing.com/parts/upi-2002-b/overview/
LT4 Hot cam https://www.summitracing.com/parts/nal-12480002 (if not LE2)
Different exhaust (I've heard flowmasters are not very good for actual flow/breathing, would love any suggestions)
Larger rear wheels maybe (fairly certain that would mean I would have to move up to at least 17's in the rear)

And that's pretty much it for now. I'll try to make update posts on things I fix for future reference or if anyone else has a similar issue

Injuneer

Elliott head porting - you send him your stock heads, he ports them and rebuilds, with option on parts used. Also ports your stock intake. Recommend that you discuss your goals with Lloyd Elliott, and have him supply a custom cam that exactly meets your needs with regard to driveability and performance. Much better results than using something like the LT4 HOT cam, depending on your specific needs.

http://elliottsportworks.com/

With the M6 trans I would recommend 4.10:1 rear gears, rather than 3.73. The 3.73's will make it feel like you added 9% more torque off the line, while the 4.10's will feel like you added 20%. And the deep O/D ratios of the T56 will be more useful, while giving up minimal MPG. When my Formula was closer to stock, a had the T56, and installed a 12-bolt rear axle w/ 3.73's. Always wished I had gone w/ 4.10's.

Caution on the rear axle though. The 7.625" 10-bolt rear axle assembly used in the 4th Gen F-Bodies is fragile. With the manual trans it will likely survive on the street, but not track friendly with sticky tire's and abusive clutch dumps. And the 4.10's just seem to make it more fragile. Again, drive reasonably with street tire's and it will survive. But push the engine upwards of 500 HP at the flywheel, or race on a sticky drag strip, and it's a ticking bomb.

Nothing wrong with a Flowmaster exhaust as long as you select the correct muffler. First question though is do you want to keep the stock manifolds or install headers? Then do you want to keep the stock Y-pipe/catback configuration, or switch to true dual exhaust. A lot of the exhaust configuration issues depend on where you live and what emissions testing you have to meet.

Wheels/tires - correct, 17" upgrade required. You can go larger with 18's if you like, but I personally wouldn't go over 18". Popular upgrade is 17x9.5" wheels with 275/40-17 tire's. Key is getting the correct wheel offset to keep the tire's from rubbing. In the back you can even go 17x11.0" w/ 315/35-17 tire's, but some minor body modifications are usually required. There is a "sticky" thread in the "Wheels and Tires" forum.

DaBwyan61

Awesome info. As of right now the power goal won't exceed 400, and I'd be happy to sit in anywhere in the mid 300's. Didn't know too much about the 4.10's but now I will start taking a deeper look into them.

Also only a select few counties in Ohio still do emissions testing and those are only by Cleveland, so no worries about passing any of those tests for now.

Chimera96

few comments on some of your ?'s

#2.
studder (misfire) under load can often be plug arc, typically at the boot. This arc can be hard to see so look in dark condition and also from under the car while it is running. Just make sure you use ramps or jack stands to get the car up in the air. A spray bottle with water in it will help enhance any arc. New plugs and wires if they are originals would be needed if arc is going on

IDK how hard it is to get to 7&8 on f-body but suspect it sucks. On my B-body I get to 7 from underneath the car. If that is the case with # 8 also you could also pull the starter for more access to that area from underneath

#3 & 4

U, joints, damage drive shaft (did something hit it), axle bearings and bent rims can cause vibrations. You will have to look closely at each area. U joints should be able to see by twisting DS and check for slop at u joint or pull DS and check. You could jack up rear end and put the car in gear with engine running and watch for any DS run out to see if it is bent. While rear diff fluid should last quite a long time, this car is new to you so check fluid condition...which basically means you drop the diff cover and at that point you put in new gasket & fluid. If there is metal shavings in the old fluid...you have deeper issues with diff bearings or gears. IMHO 4:10's and T56=good.

#6

Get a fuel pressure gauge. Check FP at idle and while driving, especially during a full WOT pull. FP should be 43.5 with the vac line off of FPR and plugged at idle. Generally it is about 37-38 with the vac line on. They make FP gauges with a hose on them so you can tape the gauge to windshield and watch by driving. HyperTech makes one but there are other brands

#8
Leak could be from anything. You need to determine if it is oil or coolant and where it is coming from, front or back of engine. If front a very common source is the WP drive seal. You need to pull Opti to replace it. Rear a common source is rear intake manifold. Run you hand along the back of the motor where intake meets block. wet oil = intake manifold leak. Leaks from side of motor can be valve cover

Injuneer

#5 - idle should be smooth and stable, +/- 25 RPM range. Programmed idle speed for the T56 trans, engine fully warmed up, is 800 RPM. The stock tach usually reads 100-200 RPM higher than actual.

Idle speed is controlled by the idle air (IAC) control valve. It's located in the base of the throttle body, and is a stepper motor with a pintle that moves in and out of an orifice in the idle air passage. The PCM positions the motor by commanding position in 'steps'. There is no feedback to the PCM as to the actual pintle position.

Many engine problems like idle speed, stutters, A/F ratio, etc. can best be diagnosed by recording the key sensor and PCM parameter readings, while driving the vehicle under conditions that produce the problem. One of the best tools for data logging the OBD-1 1993 ECM or 94-95 PCM is a free software called Scan9495. You can download for free, and need to buy or make a cable. I can help with interpreting the data, and can supply a .pdf file of a 20+ page write up I did 17 years ago, documenting the typical sensor readings and how to interpret them.

Scan9495 download:

https://www.camaroz28.com/forums/com...95-lt1-874306/

The author is a member here and provides timely assistance for any install/setup problems.

You mentioned referencing the manual on the ABS codes. If it's not the factory manual, you can download a copy here:

https://www.mediafire.com/?40mfgeoe4ctti


Great source of LT1 reference photos, part numbers, how to's, etc.:

4th Gen LT1 F-Body Tech Aids


4th Gen FAQ (mostly accurate F-Body info):

4th Generation (1993 - Present)


Dyno tests of common modifications:

WS6.COM LT1 Trans Am

DaBwyan61

I'll take these suggestions and try out what I can over the weekend, this is awesome and helpful stuff.

And as a reference I took a quick video after work of the car starting up and idling:

I tried to record the necessary things. There's a little bit of glare on the battery gauge and I forgot to mention that when you put the key into the on position the battery voltage does not climb out of the lower red zone, and will only move up after the car starts (sometimes if it is struggling giving it a tiny bit of gas starts it up). Again, not sure what the normal voltage is for the on position but just something I noticed.

I also got in touch with Lloyd and he offered some helpful suggestions to my goals. Definitely was a good idea to email him.

Chimera96

If your dash gauge (assuming it is accurate) shows red for battery with key off and does not rise until the car starts than the battery may be getting weak. Just measure the DC volts with a meter at battery with car off. Should be 12.4 ish volts. If it's 11 something or lower its not holding a full charge. Sounds like your alternator is charging correctly as VDC does go to "normal" with motor running

97rebuiltZ28

Do you know if it has a mild cam in it? I watched the video and saw and heard it's roughness and variations in rpms and I immediatly thought it could be an aftermarket cam. I definitely could be wrong though.

Chimera96

yes a "cam" would have a idle with RPM that has a slight fluctuation .....but IDK if that is your case regarding the rpm gauge

If you do have a cam your pcm likely has a "aftermarket" tune

Injuneer

Hard to read the dash on my iPad. What was the coolant temp at startup? The PCM richens the A/F ratio on cold start, and raises the idle RPM, leaning it out and reducing idle speed as the engine warms up. Tach didn't seem to vary all that much.

This is where a data log helps out, since it would be continuously recording battery voltage, coolant temp and RPM, along with many others things. Much more useful than a video of the dash.

DaBwyan61

After a look under the car over the weekend the leak seems to be coming from the front and I believe it is the seal behind the optispark gone bad. Bottom of the optispark and area around/under is where most of the leak can be seen.

Another new thing that just happened this morning is the Check Gauges light came on since the temperature gauge was completely maxed out. The needle would start going a little crazy if you started to do some long turns like on the highway and when you make a right turn the gauge reads normally, but goes back to being maxed out when you're going in a straight line. Felt the hood and opened it up to get a feel for the engine and everything seemed normal. Will work on replacing the sensor between cylinders 1 & 3.

97rebuiltZ28

If you have a code reader you could do what I do(my temp gauge doesn't work). I plug it in and read the temperature through the code reader and then you can know if the temperature is normal or not. You might want to get that leak fixed quick because your 94 has an unvented optispark which if moisture gets inside it can start to make the optispark go bad and then you've got even more problems.

Injuneer

Check the wire on the coolant temp sensor in the driver's side head.

http://shbox.com/1/temp_sensor2.jpg

Single wire sensor.

Check the sensor and 12V supply with an multi-meter:

4th Gen LT1 F-body Tech Articles

DaBwyan61

Temperature gauge is back to normal now, will probably end up replacing that sensor anyways.

I was finally able to catch a bad start on video. This was the first start up after a normal 8 hour shift on a modest day. Makes me wonder if the battery is going bad.

Chimera96

well your battery could be getting tired....or the cables/connection not solid...or alternator not charging enough...or starter getting tired

so you need to do some basic checking of the battery cables and use a DVM to test battery VDC. They should be 12.5-12.8 and with the motor running around 14+ vdc

if battery and cables check out than starter can be getting tired. Many op for the "corvette" starter from Autozone. It is a gear reduction type, smaller and cheaper than the stock starter. Just get a starter for a 96 Vette if you need one