2000 zx2 problem

[hotrod_chevyz]

It runs fine when its cold. After it warms up it seems to run fine for around 15 minutes. Then suddenly the idle drops off below 600 and the engine starts to shake. As its doing this if you stand behind the car the exhaust sounds like the engine is missing. no CEL comes on so i figured a v-leak.

Any ideas on what it could be?

[Markb873]

Vaccum leak or possibly the computer isn't compinsating for an electrical load. Does it go away with everything off? Usually with a vaccum leak after the MAF the MIL will light. But maybe it's a minor one. Good Luck

-Mark

[hotrod_chevyz]

Originally Posted by Markb873

Vaccum leak or possibly the computer isn't compinsating for an electrical load. Does it go away with everything off? Usually with a vaccum leak after the MAF the MIL will light. But maybe it's a minor one. Good Luck

-Mark

Everything was off when i tested it. I was thinking it was a leak at the TB because once it started running wrong after it warmed up, i sprayed some carb cleaner around the base of the TB and the idle came back up and it smoothed out.

So i replaced the TB gasket and it had no effect on the problem. She said when it messed up, she thought either she ran over something or something fell off the car. After looking for missings and found none visible i asked her if it could have been a backfire, she said yes.

What are the chances it backfired and cracked the intake somewhere i cannot see?

[KimMG]

After you replaced the gasket, did you try looking for a vacuum leak again with carburetor cleaner to make sure there aren't any other leaks?

[hotrod_chevyz]

Yeah, I didnt find none...I must need a second set of eyes to look at it maybe something i dont see ya know.. its a bummer too my sis really needs that car.

[hotrod_chevyz]

UPDATE:

The problem was at the elbow on the "PCV hose assembly." The PCV valve has a plastic hose that runs from the PCV valve back around to the bottom of the intake manifold. At each end of the plastic PCV valve tube are rubber elbows that connect to the intake on one end and the PCV valve on the other. The elbows are very soft and weak rubber material. The problem in this instance was a hole developed on one of the elbows causing a huge leak.

A dealership wanted $22.50 for the entire "pcv hose assembly", and $50.00 to install it. DONT BUY IT! The original ones are junk crap and a superior repair is less than $10.00 and takes about ten minutes to put on.

Buy a PCV valve with a elbow built into it, and use a very small STRAIGHT piece of fuel emissions hose to connect the PCV valve to the plastic tube. On the other end of the plastic tube, replace the elbow with a rubber "PCV elbow (chrysler)" ( auto zone help part no. 47028) you can find for $3.99 at auto zone in the "help" section of the store. You will also need to buy a couple of small hose clamps to connect the elbow to both the intake, and the plastic tube.

If you do this consider it an upgrade and anybody who has this same car check yours out and make sure you dont have a hole in it, or if the elbow is sucking flat where no air can travel through it. This car is a low miles vehicle and its rubber fittings are going bad. If you have +50k miles, replace the rubber ends i know they are bad without having to look because they are all the same.

The noise she heard originally was probably due to the PCV not working correctly. I believe the rubber end of the tube sucked flat not allowing the crankcase to vent. The crankcase eventually filled with gasses from the combustion chamber, wich blew a hole in the rubber elbow resulting in a miss.

[GrZX2000]

Originally Posted by hotrod_chevyz

UPDATE:

The problem was at the elbow on the "PCV hose assembly." The PCV valve has a plastic hose that runs from the PCV valve back around to the bottom of the intake manifold. At each end of the plastic PCV valve tube are rubber elbows that connect to the intake on one end and the PCV valve on the other. The elbows are very soft and weak rubber material. The problem in this instance was a hole developed on one of the elbows causing a huge leak.

A dealership wanted $22.50 for the entire "pcv hose assembly", and $50.00 to install it. DONT BUY IT! The original ones are junk crap and a superior repair is less than $10.00 and takes about ten minutes to put on.

Buy a PCV valve with a elbow built into it, and use a very small STRAIGHT piece of fuel emissions hose to connect the PCV valve to the plastic tube. On the other end of the plastic tube, replace the elbow with a rubber "PCV elbow (chrysler)" ( auto zone help part no. 47028) you can find for $3.99 at auto zone in the "help" section of the store. You will also need to buy a couple of small hose clamps to connect the elbow to both the intake, and the plastic tube.

If you do this consider it an upgrade and anybody who has this same car check yours out and make sure you dont have a hole in it, or if the elbow is sucking flat where no air can travel through it. This car is a low miles vehicle and its rubber fittings are going bad. If you have +50k miles, replace the rubber ends i know they are bad without having to look because they are all the same.

The noise she heard originally was probably due to the PCV not working correctly. I believe the rubber end of the tube sucked flat not allowing the crankcase to vent. The crankcase eventually filled with gasses from the combustion chamber, wich blew a hole in the rubber elbow resulting in a miss.

Hey Guys,

I'm know to this forum and really like the way you all share info.

Ok, I think I might be having the same problem with my 2000 ZX2. I took it to Auto Zone and got a reading 171 which includes a vacuum leak. I sprayed the MAF sensor, changed the O2 sensor, but my "check Engine" light is still on. My mileage is the same but the engine seems like it's about to cut off when I come to a stop and idles rough if standing too long. I know there is a vacuum leak some where but I haven't found it yet.

I also don't know, exactly, where the PCV is located. I think this might be the real problem since I checked everything else (I'm a novice, but I catch on quick). The diagrams I've seen don't totally match my engine, so I'm having trouble locating the PCV...of course the shops I took it to wanted to charge me money and attempt to convince me it's something else, but never just tell me where the PCV is.

Thanks if any one has a clear diagram, better picture, of a 2000 ZX 2000 engine.

GRZX2000

[Markb873]

It's tucked under the exhaust manifold, it's visible on the right side (looking at the engine).

[GrZX2000]

Originally Posted by Markb873

It's tucked under the exhaust manifold, it's visible on the right side (looking at the engine).

Thanks Mark.

I ended up buying a repair manual at Advanced Auto, but it's like I've heard already. The diagrams don't match up all the time, but it will work for other projects.

I bought the pcv but haven't put in in yet. That will happen this weekend unless I"m forced to do it earlier cause of my car cut off a couple of time heaed home when coming to a stop at the light. I played around with the hose a bit from the pcv and didn't hear the sucking when I pressed the gas I used to hear, so I'm sure this is the vacuum problem I've been having.

GRZX2000

[lewis0300]

Her is your solution you will need a hose clamp to. http://www.autozone.com/autozone/accessories/Help-Ford-1997-1998-PCV-elbow/_/N-25vf?counter=0&filterByKeyWord=pcv+elbow&fromStrin g=search&itemIdentifier=715889_0_0_