secondaries not opening at full throttle

[SDZR-1]

So I just finished my starter and injector install and took it for a test drive...it definately ran better than w/ the old injectors, and hey, it even started...haha. So I solved the problems that I had, but now when I press the accellerator completely to the floor the secondaries will not open....if I let back a bit then they do. Also, 90% of the time it idles beautifully but once in awhile it starts to run a bit rough. I was thinking it had something to the throttle position sensor or maybe just the plug that goes into it since it just doesnt feel like it fits as snug as it should. SES light came on periodically for about five to ten seconds each time, so I will try to get it scanned tomorrow to see what codes I am getting. Any insight would be wonderful....thank you all for the help I have recieved so far, I doubt I would have even attempted the starter/injectors w/out all the helpful info and advice found here.

Jarvis

[SDZR-1]

so i adjusted the tps and the secondaries now open at 100% throttle....but it is still just a bit rough at times...especially when I lug it down, such as cruising in 6th gear it really vibrates, but at higher rpm's it's fine. I guess I just need to hook the scan tool up to it and figure out what kind of voltage i have at the tps...who knows, maybe that is the whole problem and once it is set correctly everything will be good. anyway, just wanted to give a bit of an update.

[jonszr1]

reemb er to set voltage to .54 on the tps . do a vaccume ck on the line from the vaccume pump , just be sure that nothing got dissconnedted putting the plenum back on. dont ask me how I know:mrgreen: you might also just ck the torq on the plenum bolts when she cools off. plug wires to see if one didnt click all the way on. cant think of anthing else that I have at one time or another messed up on

[tomtom72]

off the top o my head....that CAC.com write up on the secondary vac system has the conditions for 2* engagement. I'd go back over that list of stuff. % of throttle, closed loop, oil temp, reference vacuum signal (MAP under the ECM). I know I'm forgetting something here, sorry!:o

How smoothly do the 2* actuators work? I know that some don't work smoothly at all due to mfg'ing defects upon assembly. I remember reading that over at the NetReg site in the maintenance section....I think Gordon had a bit to say about that issue. The arms were not squarely in the center of the diaphrams and when they pull the throttle levers they don't work smoothly. Also Grodon said that to make sure that when installed test them with a hand pump to verify smooth operation. I know I had to play around with mine....swap from side to side and flip them in order to get both opening smoothly and the same amount at any given vacuum setting.

Jez, does any of this make sense to you???:redface:

:cheers:
Tom

[SDZR-1]

well some of it does...but it will all make sense in time. I will post codes just as soon as i can.

[SDZR-1]

checked codes and came up w/ the tps sensor too low, which i corrected. It stil has a misfire going on which is slightly noticeable, but really shows it's face when the a/c is kicked on.

[Jeffvette]

Pull the plugs and check the condition of them for the misfire.

[SDZR-1]

I put new plugs in last week and also pulled them last nite and all looked good...the car has a rich smell to it at times but not always. Hopefully I'll figure it out tonight...or I guess my weekend trip wont be so exciting:thumbsdo:

[Corvette95]

back in the old days when I was working in a service deparment we had a machine that we could just snap over the plug wires and get a misfire or high / low kv reading in about one minute that was easy to understand and told you a lot of information, maybe Jeffvette, could clue us in on the current crop of handheld machines that will work on the LT5 that will give snap KV readings, the old bear machine I used was as big as a house.

[Jeffvette]

Scope with a timing light is what I use.

[Jeffvette]

I put new plugs in last week and also pulled them last nite and all looked good...the car has a rich smell to it at times but not always. Hopefully I'll figure it out tonight...or I guess my weekend trip wont be so exciting:thumbsdo:

Porcelein still white,chalky, sooty, black and wet.....?

[SDZR-1]

plugs still look like new...but anyway, I have determined the problem. I checked all plug wires last week before disassembly and all coils were fine...so didnt check them again, but should have. So I checked; I have no spark to two cylinders. so i guess i need a coil pack...I knew I should have just bit the bullet and installed them while I was under there the first time. Are any aftermarket coilpacks worth getting over the factory units? Thank you all for your help.:handshak:

Jarvis

[tomtom72]

Jarvis, The OEM/GM coils are most people's choice. Most of the aftermarket stuff is just hype, all brag & no real gains.

:cheers:
Tom

[Pete]

Jarvis, The OEM/GM coils are most people's choice. Most of the aftermarket stuff is just hype, all brag & no real gains.

:cheers:
Tom

I agree 100% go with stockers.

If the secondaries are a PITA just yank them out.
No secondaries No Headache.:)

Pete

[8upZR1]

I run the MSD coils and I love them. I use them on my mustang too (29psi). I am coinfident that the MSD coils + ignition box will light ANY mixture. If you are going to replace them anyway, why not put in the best. While your in there you could wire in a box and have greater control over timing. Or if you are lazy you could wire in one of the amplifier boxes. They give no timing control but increase voltage to coils, are adjustable, and have only 3 wires to hook up. MSD DIS-4 has 20 wires to hook up, but it is simple.

[WB9MCW]

If the secondaries are a PITA just yank them out.
No secondaries No Headache.

No performance issues w/o secondaries?

[Pete]

If the secondaries are a PITA just yank them out.
No secondaries No Headache.

No performance issues w/o secondaries?

No driveability issues no performance issues.

Bryan,come over test drive my Z or a friends Z both 350ci
w/no secondaries and see for yourself.

[jonszr1]

pete,do you need andifferent tune/ prom if you pull the secondaries. have you tested before and after at the strip . i would really like to do this I am so tired of chasing secondary gremlins. love to here your thoughts on this

[Pete]

pete,do you need andifferent tune/ prom if you pull the secondaries. have you tested before and after at the strip . i would really like to do this I am so tired of chasing secondary gremlins. love to here your thoughts on this


Yes,it needs some chip changes,nothing a good tuner can't do.

I have done a before and after and saw a gain of 4-6 RWHP on my 350ci and about 8-10 RWHP on the big inchers,nothing to brag about.
Lost no low end power from 2k rpm & higher.

The best part you eliminate some high priced secondary parts.

Pete

[WB9MCW]

Nice to know if you are having issues with the secondaries!

And as usual I believe you Pete-- no doubting Thomas here!

Just wanted to confirm for the others since I remember you telling me abt your removal of them on your POLO GREEN Z.