I got a 94 z28 that is missing and is also lacking power. The car has been sitting for a while until December when I finally finished putting the shorty pacesetters and other parts. This is what I have changed on the car.

The fuel pump
Fuel filter
Spark plugs AC Delco
Spark plug wires AC Delco
Removed egr and capped of openings and plugged vacuum hoses.
Removed AIR PUMP and plugged a intake air
Replaced both coolant sensors
Gutted catalytic converter
Two new O2 sensors

Check engine is on, codes are for the EGR and AIR circuit no other codes. Waiting for cable to arrive to turn off with tunerpro hopefully.

The car feels very sluggish. The car starts fine and the engine doesn't shake where one can obviously see the engine missing. I have not replaced distributor cap. Any help or suggestions would be appreciated. Thanks

 

Download this, get a cable, run a data log. Post it here.

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

Did you replace the stale gasoline with new?

Even if you removed the AIR pump, as long as there is a good fuse and relay in the circuit, it will not set a code.

Is the EGR code for the solenoid (fix with a resistor) or for EGR flow, or for both?

 

I ordered the cable should be arriving next few days
I replaced the gasoline when I installed the new fuel pump
The AIR fuse was blown and I just replaced it. The code didn't go away.
Trouble Codes are 27 and 29
When I just scanned car while running for a few minutes I was scrolling through parameters and noticed the left O2 sensor had a different voltage reading than the right O2 sensor.
Left was 770 my and the right was 35 mv. Could I have a plugged injector

 

Is the left side the drivers side. Also putting a resistor in the solenoid connector for EGR would that get rid of code. If so what would you suggest for the ohms

 

The code will not self-clear until the vehicle has been driven multiple "drive cycles" without the problem coming back. Pull the "PCM BAT" fuse in the end-of-dash panel for 30 seconds to clear codes.

DTC 27 indicates the EGR solenoid is missing. Get a ~1,000 ohm resistor and insert the wire ends in the terminals of the EGR solenoid harness connector.

Left side = driver's side = cylinders 1 - 3 - 5 - 7

Right side= passenger side = cylinders 2 - 4 - 6 - 8

If the PCM was still in open loop, you would expect the left and right bank sensors to read similarly. A large difference could be due to many causes, including an exhaust leak before the O2 sensor on one bank of the exhaust, the misfires, etc.

The two banks of the engine are controller independently. Once the PCM enters closed loop (typically about 206 seconds after startup), the O2 sensors should start cycling rapidly between 0XX - 9XX millivolts. Since each bank is individually controlled, it is normal for the readings to be different.

 

Thank you for the info. I will remove the fuse to clear codes and will check for any exhaust leaks. I will also get a 1k resistor for the EGR connector.

Let me know if this ok to do to try to see if I have a plugged or faulty injector. Monitor the O2 sensor as I disconnect each injector on the suspect side to see if there is a change in reading or value stays the same on the faulty injector.

What is a good way to check the injectors and are the easy to remove. When I drive the car it feels like the torque converter is constantly locked like an issue I had once on a 85 vette with 700r4 tranny. The lock was for the overdrive I believe. Any more suggestions would be greatly appreciated, things I can try before cable arrives, I am dreading that my final resolution might be the cap rotor or optispark

 

Your thought on checking for a lugged injector is OK. But a misfire due to other reasons can also cause the O2 sensor reading to be low. When you pull the connector off a good injector, the engine is going to run rougher. Pulling the connector off the bad injector will not make a difference, although the misfire could still be caused by problems other than the injector.

If the injector has an electrical problem, you would have DTC 18. Then you would check for +12V at each pink wire in the harness (key on/engine off). Then use a 'noid light to check whether the PCM is providing the ground required to fire the injectors.

Puling the fuel rails is fairly simply. They are held down by 4 long, skinny bolts, two in each rail. Get the harness bundle out of the way in the back of the rails. Pull the rails up with the injectors intact. Put a jar under each injector. Try and start the engine. A plugged injector will not flow as much fuel as the others. When you first turn the key to "run" and the pump primes, look for drips out of the injectors.

It may be hard to get the injectors out of the manifold if they have never been removed before. Reach across from the opposite side, pulling up and toward you. If that doesn't work, you may need to pry the rail up. Use padding to avoid damage to the rail or the intake manifold.

Do not do this indoors, or with the engine hot, or near any source of flame or spark. Have a class B fire extinguisher handy.

 

Thanks for the information. Will attempt to check them this week. Really appreciate your help. Thank you

 

I removed the fuel rail and checked the injectors. Injector #6 was bad not opening up. Removed all and took them local shop to clean and replace the bad one. The shop told me that they were in very bad shape and gave another set of clean and tested injectors. Found out that they are for V6 not V8. There was a mix up at the shop. They did not have any for my LT1 engine. I bought 8 used ones that came out of a running engine. I decided to check and clean them myself. I connected voltage to open injectors and with a syringe pushed xylene to clean them. I installed them today and tried to start the car. The car turned over 2 times and stopped. The engine would not turn, it acted like it was seized. Called a friend he thinks it's a leaking fuel injector causing this problem I waited an hour and tried again. The motor turned more than before then stopped. It never started and it won't turn . I am waiting a few hours to try again. I'm afraid I messed up the injectors by running xylene through them. I did not have this issue before.

 

I was watching utube on cleaning injectors and ran across this.-----
Fuel Injector Cleaning Without Expensive Tools,by Sixtyfiveford.I think it's an amazing video for cleaning and testing.Hope this helps.

 

Thanks for the info, I had cleaned them in a similar fashion using a syringe. The car ran before I took the rail out but was missing since one injector was bad. After re-installing the rail with the injectors that I cleaned the engine turns a few times then locks up. Try to turn ignition and it would not turn. Letting it sit for an hour I tried starting the car this time the engine turned a few time then locked up. The weird thing about this is that never happened nor was the initial problem. First time I turned it over after the rail was installed I heard a weird noise like a clunk. I hope I didn't pull a rod or something serious. So tomorrow I am disconnecting fuel pump so see if the problem was caused by a leaking injector(s). I hope that is the problem and not a rod or piston issue. Thanks

 

Remove spark plugs to see if it's hydrolocked. Pull the rails up and check for leaking injectors. Check the oil for a fuel smell.

 

Thanks that is exactly what I'm going to do. I'm leaning towards hydrolocked since its been raining after I removed the rail. Will advise. Thanks again

 

It was hydro locked. I let idle for a while until the white smoke or vapor was completely gone. It's running better than before. The engine is no longer missing. Thanks for your help and as soon as I make the connector I will get the data log to get your opinion on the data. Thanks again.