[94z2eight]

hi guys finally got the car running from all your help!:LS1LT1flag:

so now the car is running and it is running very rough while the car idles the whole car shakes as if it wants to move forward but cant because its in park. it was also having a hard time starting. so far I replaced the spark plugs only!. reason they dident have the wires in stock at auto zone.

can anyone give me things to look at to find out this problem !

car is a 95 Camaro z28 with 36k miles but car sat for a few years!

 

[94z2eight]

also forgot when I drove the car it drove very rough and was lacking power!

 

[Workman]

I havent seen your other post, but if its been sitting for years i could imagine, the gas is probably not good anymore.

 

[cocobolo95]

That and make sure plug wires are routed correctly, and are not burning on exhaust manifolds. Next check vacuum hoses for leaks, exhaust system for leaks before the o2 sensors. Also check intake elbow where it goes into throttle body. An air leak there can cause unmetered air and rough running.

Check out the diagnosing the optispark tread in the sticky threads of this section, and vatch video, run tests. Check your opti wire harness. Check connectors, pins. Then take it off and check for continuity with an ohm meter, on all pins. Finally check for excess resistance on all pins.

if you would go to the 4th gen section and open thread titled "GM service manuals", you can download the 94 factory service manual. Your 95 uses about 98% of the 94 info. Open volume 2, you are going to be finding the pcm connector symptom chart in the driveability section. This chart list the symptoms that occur with each pcm connector pin, when there's a problem there. Look for the one's that cause rough running, stalling, etc. Then test to make sure the proper signal is getting through on those pins.

Check all pcm and engine grounds. If an automatic, check your trans wire harness. This is because the trans gets it's power from same fuse as coil & icm. If there's a problem with trans electrics or wiring, it can mess with the voltage available to coil and icm.

 

[94z2eight]

ok thank you guys I will try everything you guys advice me to try. As of today this is what I did I started pulling each connector off the fuel injectors one by one and non of them seemed to make the engine sound worse. so I don't think its much of a fuel injector problem I also did the same this with the wires off the opti. the car is just running rough when you go to give it gas it lacks power. and when you take it out of park it moves forward and back. also the exhaust makes a loud noise and a popping sound I think im going to cut off the exhaust tommrow maybe something is messed up in there or clogged. would a clogged cat do this to the car? thank you guys!

 

[cocobolo95]

If you pull the injector wire off, the car should drop rpm as no fuel is now going to that cylinder.

 

[94z2eight]

Yes everytime I pulled one off the car would sound like it was going to stall


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[94z2eight]

I think I'm going to start by cleaning the maf, see if cat is clogged clean iac and take it from there? What do u think also because the owner before me said he would get $20 in gas drive 20 miles and it was all gone so I'm thinking bad gauge or gas is just dumping and runnied the cat? What would be a reason the car would be eatting gas that fast dirty maf?


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[cocobolo95]

Might want to get a cable that conects car's dlc to usb of laptop or notebook. Get at ALDL OBD1 OBD cable OBDI OBD2 engine codes then download a scanning program to check your sensors and see what they're saying. obd1 scan program available in 4th gen section for free. Also DataMaster is available to download as a trial version at TunerCat It gives 20 free data logs and unlimited data playback. The data log shows sensor readings in real time. It also can be uploaded so members can help you figure out what's wrong.

If unsure of what sensor reading mean, pm me with your e-mail address and I'll send you the pdf file "sensor readings and what they mean".

Poor gas mileage can be caused by any number of reasons. That is why you should do a running sensor scan. This can pinpoint or eliminate the pcm, or sensors as the suspect.

But other things can cause the sensor readings to be off, such as; power to components, grounds, wiring, connectors, connector pins, etc.

Lastly, mechanical problems in engine, transmission, even things like brakes that are dragging, clogged cat, etc. So you will have to do some investigating to find the cause.

Troubleshooting involves an organized, systematic approach of eliminating suspects until you find the one or ones causing the problems.

4th gen section has 94 factory service manual, available for download. Look for thread titled "GM service manuals" Volume 2 is dedicated to driveability, emissions, and electrical. It will have a pcm symptoms chart, which tells what symptoms occur when pcm wiring is not right. It has a pcm voltage chart which tells the correct voltage on pcm wires, with key on and car running. Full wiring diagrams, pcm connection to sensor chart, troubleshooting charts, etc.

 

[94z2eight]

Ok thank you so much so far I removed cat it was clogged I cleaned out throttle and idle air control valve also cleaned maf with cleaner it's still running rough but not as bad just seems like it's running on 7 cylinders instead of 8


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[94z2eight]

Hey so my car is still running rough and no codes are pulling up I replaced fuel filter it was dirty car starts up better now. So when I leave the car in idle it shakes and when I put it into gear it shakes more ? What can it be


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[Workman]

Try a compression test.