The 6 cylinder Z

[ghlkal]

When I purchased the Z in April it ran poorly. I figured I would have to change the injectors. In the past few weeks it started running horribly.

I finally got a Tech 1 and was eager to see what I could find out. I was hoping to do the “injector flow” test, but I can’t (subject for another thread sometime).

I ran the “injector balance” test with my Tech 1 that allows you to turn off individual injectors. When I commanded injector 1 off, there was a noticeable drop in RPM. When I commanded injector 3 off, there was no change. Hmm. As it turns out injectors 3 and 6 are dead – no change between idle speed with them on or off. I did check spark to 3 and 6 and there is spark.

I was planning on pulling the plenum and cleaning / changing everything, including all 16 injectors, over the winter. My wife and I planned a trip in mid-August and I was hoping to take the Z.

Before I jump to conclusions, could this be anything else other than 2 really bad injectors? It seems to me that I’m running on only 6 cylinders, and the car is sluggish enough and shudders enough to verify that. BTW, I did replace the plugs just because I don’t know how old they are (they had been replaced and I stuck with the AC 41-602).

We have ethanol in our gas here in WI. The car came from TX. Does TX not blend their gas with ethanol? Or, is it the fact that I’ve driven the car nearly 3500 miles since I bought it and it was time?

Thanks for sympathizing with me

Gary

[Kevin]

time to call up fic and get 16 new SS injectors, don't bother with the rebuilds you'll be doing it again if you do

[ALZR1]

Originally Posted by ghlkal

When I purchased the Z in April it ran poorly. I figured I would have to change the injectors. In the past few weeks it started running horribly.

I finally got a Tech 1 and was eager to see what I could find out. I was hoping to do the “injector flow” test, but I can’t (subject for another thread sometime).

I ran the “injector balance” test with my Tech 1 that allows you to turn off individual injectors. When I commanded injector 1 off, there was a noticeable drop in RPM. When I commanded injector 3 off, there was no change. Hmm. As it turns out injectors 3 and 6 are dead – no change between idle speed with them on or off. I did check spark to 3 and 6 and there is spark.

I was planning on pulling the plenum and cleaning / changing everything, including all 16 injectors, over the winter. My wife and I planned a trip in mid-August and I was hoping to take the Z.

Before I jump to conclusions, could this be anything else other than 2 really bad injectors? It seems to me that I’m running on only 6 cylinders, and the car is sluggish enough and shudders enough to verify that. BTW, I did replace the plugs just because I don’t know how old they are (they had been replaced and I stuck with the AC 41-602).

We have ethanol in our gas here in WI. The car came from TX. Does TX not blend their gas with ethanol? Or, is it the fact that I’ve driven the car nearly 3500 miles since I bought it and it was time?

Thanks for sympathizing with me

Gary

Our z's are notorious for having bad injectors,even replacement injectors.
so yeh I would say it's your injectors at fault here.

AL.

[tccrab]

I'll be the first, you have my sincere sympathies.
I too had a similar experience when I bought my '90.
It was a very low mile car, only 9600 miles, and it was kept in an air conditioned warehouse full of collectable Corvettes.
When I drove it out of the warehouse, it ran smooth and fast with no problems at all.
Less than 500 miles later it developed a miss and, well, you know the rest of the story.
At the time, the only choices were:
- original Multec's, ($$$$ and will absolutely fail every time)
- RC Engineering ($$$, way more than I wanted to spend as I had just bought the car)
-Accels, new at the time and had not yet passed the test of time. Price was right though.

Now, there are FIC injectors, and the good news is that they stand behind their product and so far have had nothing but good reviews.
Pop the plenum, stick in a full set of whatever injectors you want to put it and then......

Drive It Like You Stole It !!!


'Crabs

[Kevin]

Originally Posted by tccrab

Drive It Like You Stole It !!!


'Crabs

almost went to jail doing that yesterday

[tccrab]

Originally Posted by Kevin

almost went to jail doing that yesterday

Been there, done that.



Just been lucky so far........

'Crabs

[Kevin]

Originally Posted by tccrab

Been there, done that.



Just been lucky so far........

'Crabs

the phrase "non-calibrated speedometer" are now the three sweetest words in the english language. 80 in a 45 is what he got me at I was well over 90

[ghlkal]

I just ordered 16 new SS injectors from FIC along with Jerry's Gaskets. The plenum pull DVD from Marc Haibeck is on its way too.

I've run out of vacation time, but I'll get started and do a little as I can get to it.

[scottfab]

Originally Posted by Kevin

the phrase "non-calibrated speedometer" are now the three sweetest words in the english language. 80 in a 45 is what he got me at I was well over 90

reminds me of my 78 in a 55 and I as going double the 78.
I was a happy camper and smiled at the officer and said "thank you"
when he handed me the ticket