LightningMcQueen

well i got a 95 trans am lt1 and i've been having trouble for almost a year with it. ever since it got the long tubes its been bogging down. when i cruise it the rpm's start to choke up a little likeit boggs down or like if its not getting enough spark or something and then i give it gas and it goes away. and something when i take off from a stop/light the rpm's drop all the way down like if its gonna turn off. dont know what it is. what do you guys think it might be? anything would help THANKS

SS RRR

iTrader: (2)

Thoroughly check your plug wires for any cracked/burnt marks. You can also do this by running the engine when dark to help possibly pinpoint if/where spark is grounding out on a primary. You may have burnt plug wires. The idling thing may be a different situation. I know when I did my headers years ago the engine would drop to around 500rpm and sometimes die when coming to a stop. This happens for about a weeks worth of start cycles and then goes normal. I have never found out why.

WhyHelloOfficer

iTrader: (5)

+1
Burnt/Cracked plug wires are a very common cause, typically after a header install. Did you run the plug wires over the valve cover or through the stock routing?
Are you using heat shields/socks on the plug wire boots?

Also -- did you replace your spark plugs at the same time? If not, it might not hurt to replace them while you are checking your plug wires. Put a little bit of dielectric grease in the boots as well when you are putting everything back together. It will help with the connection to the spark plug as well as keeping moisture out.

Lastly -- check your O2 sensors. If you got ceramic coated headers, sometimes the coating can burn off in the first few cycles of the headers and can foul up the O2 sensors. Along those lines, ensure your O2 Sensor extenders are in good shape and haven't gotten burnt/melted on the header primaries or collectors.
Did you use plug and play extenders?
I know when I received my pacesetter headers, it came with really crappy wires to extend the harness and crimp connectors. These are far from ideal for a long term, water-resistant, quality connection. If you haven't bought the plug and play ones, I'd shop around for some.

If you do need to replace your O2s, stick with AC Delco ones. The Bosch O2s you get from your local DAP typically don't have very good results. A cheaper alternative that I used for over a year without problems were the NTK (NGK) O2 Sensors. They were a little less expensive and worked well.

SS RRR

iTrader: (2)

If you did replace your plugs it is also possible, because of the cramped space you may have cracked the porcelain on one or more...

LightningMcQueen

well i checked the plugs and they seem ok but ill double check again and the 02 sensors i had to cut the connection and put wires straight thru can that be the problem

1 Craz28

Sounds like the problem I was having. At idle after warmed up, give it gas and it just falls on it's face, even hear a clunk under the hood. I think it was an exhaust leak from the check valves and gaskets. Do you have a tune?

1 Craz28

Yes, also the EGR. After taking the car out for a cruise. It ran great! Everything is metering and working properly. It idles perfect. But I noticed at idle when stopped, I think the EGR opens, then when you give it first throttle it is very sluggish until the EGR closes. This is why they deleted EGR on the LT4 and other high valve overlap cams? But, it does aid in cooling the combustion chambers. Especially at idle at a stoplight. I think one of the most important things to someone not going totally drag raced out, is to make sure you use GM electrical sensors for your SPECIFIC car! The ICM in particular is very year specific as well as man., auto specific EGR valves and IAC, TPS, MAP, and O2's! Good luck.

LightningMcQueen

na i dont have a tune. and what do you mean by exhaust leak from the check valves and gaskets

quik95lt1

iTrader: (7)

Ok heres the issue, if there is an exhaust leak before the O2's (at the header to head flange) it could cause an issue with the motor running excessively rich. However when you put headers on these cars they do tend to get a bit rich at part throttle. The hesitation you are feeling is most likely the car begining to load up the cylinders with fuel at part throttle and when you open the throttle blades and let the extra air in it burns it up becuase the motor goes under a load. Have the car tuned and i can almost guarantee it will go away. Also check the obveous plug wires being burnt and make sure they are all snapped on the plugs/cap good. If you deleted the EGR you will also need to disable this in the ECM because this will cause the car to target a very rich 11.7 AFR at WOT. When a car is fitted with headers a tune should immediatly follow. Every car I have ever put headers on I have tuned within a week becuase of these issues, and I like to go fast

Hope this helps.

gixxer75094lt1

iTrader: (8)

my car when i first got it (ten years ago) always seemed it was idling low. specially after the lt install it seemed it dropped even more. off the line it bogged and low end was terrible. after messing with it for months, replaced plugs wires, checked for exhaust leaks etc etc i gave in and got a pcm tune and it was like night and day. i never thought at that time just replacing headers and catback would benifit with a tune but thats the only thing that cured the problem.

other than checking for leaks, plugs and wires, the 02 sensors not sure what else is left. id get a tune done for sure.

WhyHelloOfficer

iTrader: (5)

Does it break up/miss/backfire when you are at WOT?

If it is fine when the engine isn't warmed up, and at WOT, then it seems like it is probably the O2s. Either go buy some quality O2 Extenders from Summit/Jegs/Forums sponsor or make your own (with soldered connections and waterproof plugs).

djjab57

iTrader: (17)

After i installed my LT's mine did the same thing, I have burnt the 2nd plug wire on the passenger side 3 times. And i couldn't see it the first time in the dark cause it was well hidden. Recheck those wires, i kept looking and couldn't see it until i got under the car and bammmmm burnt up

1 Craz28

The check/valves simply allow the AIR pump to blow fresh air into the exhaust system on start up. It "pressurizes" the system and in my case with unheated O2's is very important. When the check/valves go bad they don't close and let exhaust out the air pump.

LightningMcQueen

thanks