Cutting off still! PLEASE Help!

[wishuwerehere82]

You have 1 O2 sensor located below the the passenger seat on the exhaust system. It has a connector to the Purple wire on the end of the sensor. Unclip the connector and remove the old sensor out of the exhaust pipe with a box wrench and replace it with a new one. It's around $36.00 for a new one and easy to replace.

The O2 sensor is wired directly to the ECM which is located in front of the battery. So if changing out the sensor doesn't fix it, you may have some oxidized contacts on the two connectors that go into the ECM.
I get 24.6 MPG on my '82, if that gives you an idea about what a ballpark figure is.

The IAC's are on the front of the Throttle Bodies, they are round gold colored cylinders about 1-1/4" in diameter with wrench flats on them. There are connectors clipped to them. They easy to replace also, but a little more expensive than the O2 sensor. Just unclip the connector, unscrew them with a large wrench(or channel locks) and replace with new ones and clip the connectors back on.

 

[wishuwerehere82]

Since you recently had a leak in you radiator and may have lost enough coolant to overheat the heads, combined with the tapping noise. I would drip a little top end lubricant(like Marvel Mystery oil) through the TB's to oil up the valve stems to see if the problem goes away. Not too much at a time, just a few drops into the Throttle Bodies to add to the fuel/air mixture. If a valve is sticking, that should free it up.

Have you checked to see if you are losing any coolant now that the radiator is fixed? That could indicate a burned head gasket or a warped head.

 

[MoeJr]

Corvette only techs or not it seems they know little about the Cross fire. Get it to Alan76 and let him set the throttle boddies and IAC's. This is crucial and if they are even a little bit out of sync they will cause all kinda problems.

 

[flynbyu82]

I wish Allan would get back to me about his avaliability and location. Leave me a number Allan!

No more coolant leaks since the replacment of the radiator. I'm going to look into replacing the IACs and defintly the O2 sensors.

I will take into consideration everything everyone has said, thanks abunch for all the help and keep it coming!

 

[wishuwerehere82]

You should be able to do the IAC's and the O2 sensor(1) in about an hour.

 

[flynbyu82]

I'm putting a new O2 sensor in this afternoon,I will let you all know how it goes. I bought a 20$ that will work for now, but I'm probly just going to order a factory one further down the road.

BTW, a few questions:

The shop I recently took it to replaced my thermostat and put a 180 on there instead of a 195 like it had. That wouldn't effect anything would it?

When they replaced my radiator, they filled it with the new red coolant, called Diotrex or something like that. Anyone have any experiance with this stuff?

 

[wishuwerehere82]

The 180 thermostat probably won't cause any problems with the anti-pollution stuff since it turns on around 160 degrees.

The red coolant is extended life coolant and should work just the same as the green coolant but last longer protection-wise.

Good luck!

 

[flynbyu82]

Alright, replaced the O2 sensor, took it out for a drive, and it worked fine, idling alittle low.

I get back to the garage and as it's rolling in it dies. Now it's like won't start back up, and once it does start back up I have to like sit on the gas to keep it going otherwise it dies. I really just need to find a tech around here that knows Crossfire

 

[Evolution1980]

Ain't older cars (vettes) wonderful??? They are a lot like Harley's... 1 hour on the road, 3 hours in the garage. :L

Eventually you'll nail down the problem. It still wouldn't hurt to go over all your vacuum connections. That thing about your headlights popping up is still ringing in the back of my head as a vacuum issue, which could be still causing your problem. Even if it's not the cause, it's at least one thing you can eliminate for certain.

 

[wishuwerehere82]

Flynbyu82,

After reading over your post again, I'm starting to think that your fuel pump is dying out. The reason I say this is that when at idle, your pump is flowing less than at any other time, also in stop and go traffic. The pump starts to slow down under low flow, and sometimes it will stall. After it sits for a minute, the pressure regulator allows the pressure in the system to bleed back through the vent line back to the tank. Then it starts back up because it doesn't have any backpressure on the pump.
When the pump on my 82 went it was miles from home and resulted in a $260.00 tow back to my garage, then it started back up as soon as it was off the flatbed. The tow truck driver said 60% of his business was from fuel pumps failing. I changed it the next day and haven't had a problem since.

 

[I_R_DA_ONE]

Check your cats and see if one of them is plugged.....they will make the engine think its pulling a house trailer....and also give enough back pressure to make an exhaust leak.....
Mike R

 

[jdp6000]

I have an 82. What you are describing could be caused by a number of things.Lets go back to the beginning. You say the problem stopped after you replaced the expansion tank and then started again when the rad was replaced. For starters check your coolant level, it must be full or the CTS (Coolant temp sensor) in the front of the engine won't work. Next was the thermostat relpaced? Minimum 160 degrees I hope. Your CTS could be bad. Its cheap to replace.

Idle of 800 to 900 is high for these cars. In gear you should be around 550 some like it up around 650. Some one indicated you have a vac leak? do you? You should find it and fix it. it may explain the higher RPM. A bad CTS could also cause a high idle. It may be telling the computer the car is cold.

The 82 is a crossfire and has 2 IAC's. I doubt they are your problem. If you take your air cleaner off and rev the engine you should be able to see the pins on the IAC's moving in and out. When you put the car back together did you hook up the hose that goes from the rear TBI to the air cleaner?

Did you touch any thing on the TBI's? For example the TPS on the rear TBI?

Does your Oil pressure guage work? If not a bad sender could cause your car to cut out but not usually with a drop in RPM first.

If its none of the above it could be your fuel pump as someone suggested. I would have someone check the fuel pressure between the two TBI's. It should be between 9-13 psi and steady.

What does the car do when you first start it? How does it run other wise? Any hesitation?

Jim

 

[flynbyu82]

Now I am almost thinking it's something to do with the spark plugs. All the plugs have good current, but when I start then car and it starts to bog down, I can smell unburned gas, almost like a piston isn't igniting or something. I'm going to replace the plugs and wires with factory.

Thermostat was replaced. When I replaced the O2 sensor idle dropped back down.

Havn't messed with TBI or TBS. Oil pressure gauge works.

Car seems like it's getting plenty of gas. It's like its getting over-fueld and just gets bogged down. The car does have alittle hesititation at times. Rumbles alittle unsteady on acceleration. I really havn't been able to get it out because of how bad it is now.

Evolution
My father said the same thing about the Harley remark, bringing tools with me everywhere I go , what a concidence lol

I will look into the fuel pump again, by I don't beileve it's that because of the unburned gas I'm now smelling. It's seems to be getting plenty of gas.

 

[wishuwerehere82]

OK, if it's not gas then it must be spark.

The distributor has an Electronic ESC(Electronic Spark Control) module inside. If it's old or poorly connected to the connectors or the distributor it can fail when heated up. It's a curved looking module with connectors on both ends and is heat sinked to the distributor body. Pull the cap and rotor off to get to it. They are pretty cheap to replace and would be worth the time to do it. Make sure to use the thermo grease on the backside heat sink that comes with it.
I'm not saying that it will fix the problem, but it could. It would not send any codes to the ECM if it failed. If you are replacing spark plugs and wires again, make sure to take the extra time and effort to route the wires up through the motor mounts for the #1,2,3,4 wires. Otherwise there's a good chance that they will burn against the exhaust manifold.

 

[MoeJr]

My Vote is for fuel pump. My 84 acted just like yours when mine was going south. Had the pump replaced along with a good TB sync and my car has been rock solid for almost 3 years.

 

[wishuwerehere82]

My Vote is for fuel pump. My 84 acted just like yours when mine was going south. Had the pump replaced along with a good TB sync and my car has been rock solid for almost 3 years.

I'm with you.

 

[flynbyu82]

EGR valve for anyone who was wondering. I took it took a local shop where the guy usta own a 82. It saved me a lot of money and time than going to the 'Corvette specialists' and he's actually fixing the problem.

Thanks for everyones time and effort and I will surly post if I have anymore problems.

 

[wishuwerehere82]

Let us know how your gas milage is now that it's fixed.
We all should have thought about the EGR valve, bad us.