Exhaust changes causes problems

[rogerzr1]

Originally Posted by bradslt5

roger , let me ask a couple of ?s when you turn the key to on not star do you here the motor for the vaccume pump come on in thge right front up by the headlight . does it go on and shut off or does it cycle on and off?. did you ever get the helm manual yet ? if not you really need one it would help you alot in deducing your problems .pm me if you still need help and i will seeif i i can walk you thru some ideas to help brad

Just checked the car. Now the vaccum is not coming on when I turn the key. I know it was working before I took my drive. Any idea what happened. Is there an easy way to tie the secondaries open to check if this is the problem or if its just another problem?

When I turn the key the vaccum makes two little noises and then doesn't do anything.

Seems like I get one thing fixed and something else breaks. Anyone found any of that dynamite for me yet?

[rkreigh]

where in Ga are you???

SGC is in thomasville and can take some headache away if you don't want to work on the car. one thing I found which can be embarrasing but it's common. if the injector wiring isn't clipped on securely they can pop off!!

you then have one or more secondary injectors that don't get any juice!

you can check for this by ohming out the injectors with the plenum still on

see

www.zr1specialist.com

for the procedure

the exh probably doesn't have anything to do with it, as mentioned above it's just letting you hear what you didn't before, and if you were a bit lean before, you are a bit leaner now!!

the stock chip should work fine. definitely need to change that other 02. one new and one old isn't a good idea, they are hard to get to. just another reason to put those headers on!

good luck. my bet is that you have a bad plug wire or coil pack. fairly common.

you can test that by pulling one plug wire at a time and putting a grounded plug in the wire. when you see a weak spark, you typically found out which is misfiring.

pull the plugs and have a good look at them, they reveal alot. if the injectors are leaky (probably not) you can often smell it from that cyl with the plug out.

the lt5 isn't that tough to work on, just be patient and get the factory service manual to keep you on track. has some great troubleshooting flowcharts that really help.

[bradslt5]

Originally Posted by rogerzr1

Just checked the car. Now the vaccum is not coming on when I turn the key. I know it was working before I took my drive. Any idea what happened. Is there an easy way to tie the secondaries open to check if this is the problem or if its just another problem?

When I turn the key the vaccum makes two little noises and then doesn't do anything.

Seems like I get one thing fixed and something else breaks. Anyone found any of that dynamite for me yet?

roger ,there is a fuse on the driver side of the car just in front of the brake master cylinder on the inside of the wheel well its a 10 amp its for the vaccume pump. it may be blown as mine was

[rogerzr1]

Originally Posted by bradslt5

roger ,there is a fuse on the driver side of the car just in front of the brake master cylinder on the inside of the wheel well its a 10 amp its for the vaccume pump. it may be blown as mine was

Ok, checked the inline fuse, it was fine. Is there anything else I should check electrically for the vacuum pump.

Again, when I turn the key the pump now clicks twice. Before it use to run for a couple of minutes.

Pull the vacuum hose off at the bottom of the pump. But your problem does not lie here. Take one thing at a time.

Roger, I'll give you a shout in a few.

[rogerzr1]

Originally Posted by Jeffvette

Pull the vacuum hose off at the bottom of the pump. But your problem does not lie here. Take one thing at a time.

Roger, I'll give you a shout in a few.

What do I need to do next. I drove the car tonight and it drove pretty good. I don't hear the vacuum when I turn the key, but it sure seems like the secondaries are working.

[bradslt5]

roger ,pull the connection off the vaccume pump then go and turn on the ignition and listen for the pump to turn on . if it doesnt run all the time with the hose off it could have a problem. here is where i have a tough time i dont know how to show you the link on that stuff . i can bearly type . on corvette action center in the zr1 area is a good thread on the secondary system and the vACCUME PUMP TOO. hope nthis help s going to get busy . grass is getting ready to grow , have to paint the new house after work . wife a has found a new toy this foam that is so light you cant feel it till it oooozes out of things like gloves hats shoes . i gotta be the only married guy in the world whose pregant wife turned into the biggest prankster ever born. sure is fun

[rogerzr1]

Originally Posted by bradslt5

roger ,pull the connection off the vaccume pump then go and turn on the ignition and listen for the pump to turn on . if it doesnt run all the time with the hose off it could have a problem. here is where i have a tough time i dont know how to show you the link on that stuff . i can bearly type . on corvette action center in the zr1 area is a good thread on the secondary system and the vACCUME PUMP TOO. hope nthis help s going to get busy . grass is getting ready to grow , have to paint the new house after work . wife a has found a new toy this foam that is so light you cant feel it till it oooozes out of things like gloves hats shoes . i gotta be the only married guy in the world whose pregant wife turned into the biggest prankster ever born. sure is fun

Brad, I checked the vacuum pump and it turns out it is working fine.

I talked with Jeff and he thinks it could be a few things. I am going to try and elimenate them one by one.

Sounds like you are going to be a busy man pretty soon. Your wife sounds like quite a gal. I guess you have to watch everything you put on, or it might have a suprise in it.

[Sgreg]

I had a few of the same symptoms and guess what; it turned out one of the crappy rachet plastic clamps came off a fuel pump hose allowing fuel to be pumped around the tank instead of to the injectors. Replaced plastic clamps with stainless clamps and all was well. Just another possibility.

[rogerzr1]

Just got back from about a two hour drive in the Z. The car didn't stumble at all during WOT.

The Z still has a pretty good hesitation at lower rpms. The acid test, as Paul Workman put it, low rpms and floor it, my car stumbles every time.

Jeff did you get my pm with my address?