dctrumpet

iTrader: (10)

I just got done removing the smog pump and all the emission hoses on my 1992 firebird. Plugged the holes in the exhaust manifold with 1/4" brass NPT plugs, re-routed my belt using a 97" Dayco belt. removed my EGR solenoid and vacuum lines from throttle body to solenoid and from solenoid to EGR valve. capped off the front of the throttle body vacuum port. I capped the valve going to the converter that is located on passenger side near the firewall.

Car ran great before now it has a horrible roughness and idle to it. shakes like a dog pooping a peach stone, lol. Have I overlooked something? Do i need to re-burn my chip?

Car was originally a 305 tbi. Now it is a 350 tbi. Moates modifield my ECM to accomodate his chips. Brian from tbichips.com has assisted me with my logging and created the .bins so i could burn them. So, I figured since my car was doing well with performance i just needed to clean it up.

Now it runs horrible. Have not test drove it as of yet. Just started her up and it is rough almost like a misfire. I checked EVERRYTHING out and i cant find a problem.

Thanks for your help guys!!!!!

redlsed88

i could be wrong but im pretty sure the lack of egr solenoid may be your problem do you have a service engine light? car may be running in "limp mode"

also double check your vacuum lines maybe there is one thats not connected that needs to be

dctrumpet

iTrader: (10)

No SES light at all. The chip that was burned for me is a based on a stock chevy caprice with a 350 tbi. Those did not have an egr solenoid thus, my chip does not have the parameters for that. At least I am not aware of it, lol. Tbichips.com and Moates both told me to remove them.

The chip has been "tuned" at least 4 times so it is not "stock" for the fueling, etc.

Fast355

iTrader: (2)

I beg to differ, the Caprice DOES have an EGR solenoid, even the 9C1! I happen to have owned a TBI 350 B-Body and it had one as well.

dctrumpet

iTrader: (10)

I stand corrected, lol. I was told that the caprice did not have an egr solenoid. I just did a brief research and they have same one that my car has. I apologize for the error.

Is this my problem? Should i reinstall it? How do i get around not having a EGR valve and solenoid? Seems that many remove theirs without problems.

Thanks for the advice and correction.

Fast355

iTrader: (2)

I am going to guess that some sensor got removed, disconnected, etc.

Perhaps you broke a spark plug or plug wire. Maybe one is off!

It is also possible that the plugs you installed in the exhaust manifolds are leaking air into them and throwing off the O2 sensor reading.

I had a TBI setup on a performer RPM intake and ran the stock chip for months with no ill effect. Just a check engine light when you drove on the highway for long periods of time at steady speeds.

dctrumpet

iTrader: (10)

the 90 Caprice has the same EGR vacuum solenoid as the stock tbi firebird, but the EGR valve is different. Would that matter at all? Does the EGR valve make a difference for the 350 compared to the 305?

cheese_kake

There is no good reason to remove the EGR except to make more space, but its already inconspicous and doesnt really inhibit anything. All the EGR does is, at crusing speeds it takes exhaust gasses and reburns it again by injecting it back in the manifold. If you remove it your car will actually pull timing.
There is A TON of information about the EGR and its purpose. I suggest you go to the tech article on this, there are no positive affects of taking off the EGR other than, getting the ugly thing off the motor and the fact that most people dont know what it does and just assume take it off.

Also your smog pump, if you take it all off you removed the solenoids on the diverter valve, when you remove this it may set off the o2 sensor, because the smog pump injects fresh air in the manifolds and if you take it off then the sensor gets a reading of lean condition and will pull timing to reduce detonation aslo You will find alot of info on this.

Good Luck !!

Fast355

iTrader: (2)

I have not noticed any ill effects by using a 305 valve on a 350 or vice versa. In fact the older carb cars are almost always the same valve. TBI Vans/Trucks use the same valve on 305s and 350s. There are two different part numbers, but their useage is Federal vs. California emissions.

cheese_kake

At NAPA, there are two EGR valves for all of the chevy V8's 82-92. Only the other one as mentioned earlier is for the calif. codes. But there shouldnt be any diff with interchanging any of them with alike years. Also if you have a rough idle, pull on the bottom of the EGR if its stuck you need a new one. Also put a vaccum gauge on it to see if its holding vaccum. A quick way to check it is to pull the bottom of the vavle up and while its up plug that nozzle with your finger and release the valve and if the valve stays up its holding vaccum and when you release your finger it falls down.

Fast355

iTrader: (2)

Neither of these are that big of a deal. You MIGHT experience a little off-idle acceleration pinging and the associated timing retard, but it is not likely. The factory already runs a lame timing curve on the TBI engines and removing the EGR valve does not really effect it.

I swapped to a non-ecm control scheme on my EGR when I swapped to the EBL. The VE tables stayed the exact same with and without EGR. The spark requirement changed very little, 1-2* at most.

Then lets move on to the air pump issue. The computer could care less if it is there or not. The air system goes into divert or downstream mode as soon as the coolant temp warms up enough for closed loop. The original 1992 G20 serpentine setup that I swapped my 1983 lacked the pump, bracket, etc. Winaldl still showed the status of the air switching/divert valves though. They weren't there, but the ECM was still attempting to command them. Remember that this is the factory 299 ECM from the 1992 G20 as well. NO ill effects by eliminating the smog pump.

dctrumpet

iTrader: (10)

Prior to the removal of EGR "stuff" and smog components today the car ran great. It did have a slightly rough idle, but nothing of an issue.

The EGR valve is brand new A/C Delco and functioned fine.

I have done the search on EGR solenoids and smog pump and the solenoids associated with it. Still confused on the smog stuff.

From my understand and literally about 5-6 hours of research on here it should have been an easy mod to my 350 tbi without any performance issues.

The reason why i did what i did today with the removal of ALL the smog stuff and EGR was based upon literally hundreds of posts on this very subject. I have learned that i must do my research first before posting questions on these boards, lol. It is such a valuable board here and you guys have been awesome.

cheese_kake

Are you saying that the EGR if removed isnt a big deal. Yes it is, the only case it wouldnt cause a problem is if you tuned a new prom.

Second the diverter valve solenoids, are not a major problem, but what I described does take place. Read TRAXIONS thread on this, hes a guru in all
the closed loop and prom functions.

No the computer DOES care if the pump isnt there. The solenoids are part of the wiring harness therefore it is connected to the computer, therefore it matters. Never did I say that it would pull alot of timing, but it will pull some. Read the thread about this its a sticky in one of the forums.


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Ok, bottom line guys, he took it off now it runs like crap. When it was on it ran fine. Whether minor or major it makes a impact. Things like this arent always a definate. You change one part on a car it impacts other things. The other things that become a factor in these things are the tune of the car, and if all the other sensors are working properly. I took it off on my car, didnt do anything notiecable. BUT my car was in perfect tune, PERFECT, all brand new sensors, and ignition and proper timing, fuel pressure.

Fast355

iTrader: (2)

EGR removal will NOT cause the problems he is seeing. EGR is inactive at IDLE and therefore not the cause of the problem.

The AIR divert/switching valves will be in the downstream (into the cat) or divert modes at ALL times when the engine is warmed up. Therefore they WILL have ZERO effect on the way the engine runs. If it made a difference GM would have released two different proms for trucks. One for air pump equiped and one for non air pump trucks. Take the ASDU 350 .BIN for example. It was used with an air pump and without. Makes NO difference.

The air valves are connected to the ECM, but they are on an output. There is no feedback to let the ECM know if they are working correctly. There are no codes for the air valves. Removing them will make NO difference.

dctrumpet

iTrader: (10)

I will replace the EGR system back to stock. If the car runs rough after the installation than I know there are other issues.

I have rechecked the plug wires, plugs, all vacuum lines and.... So, I will reinstall the EGR system back.

Thanks. Will keep you posted
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This is a fun post, lol. Battle of the ....

FAST355 you are saying that i should not have any performance problems with the mod i did today? Correct? Assuming I didnt mess up something else like a sensor, wiring, etc. I have checked it several times, but I will go over it with a fine toothed comb tomorrow.

cheese_kake

When I had my old EGR in place sometimes at low rpms mainly in reverse it would almost stall and I replaced the EGR and it was much better BECAUSE it was stuck open.

Read this and the rest of the AIR PUMP SYSTEM, its a sticky in the exhaust forum.


***************************************************
* >>> Air Injection Managment Tables & Param's <<<
*
***************************************************
LC2FF: FCB 00 ; Max Air to ports if in Pwr Enrich
; If In WOT >= then divert Air, (Sec)
;
LC300: FCB 10 ; Divert if If RPM Cont > ____ > 10 SEC
; Cal = Arg * 10, (1 Sec)
;
LC301: FCB 170 ; If Filtered o2 > 0.752 vdc for ___
; Then divert
; Cal = Arg * 226
LC302: FCB 56 ; If Filtered o2 0.247 vdc & in closed loop
; > Then divert
; Cal = Arg * 226
;
LC303: FDB 200 ; 20 sec Rich or Lean o2 Divert timer
; Cal = Arg * 10
;
LC305: FCB 160 ; Divert if cont > 4000 RPM & time >
;
LC306: FCB 10 ; Enable air to conv If > 1 SEC since
; last neg delta LV8 > is <
;
LC307: FCB 25 ; If LV8 < 25 then Divert
LC308: FCB 100 ; If LV8 > 100 & MPH > Divert Air
LC309: FCB 60 ; If > 60 MPH & LV8 > then divert
;
LC30A: FCB 64 ; Enable air to conv if in open lp
; & 100 Msec Drop in LV8 < 64
;
LC30B: FCB 73 ; If Cool < 14c, (58.5f) then divert
; Cal = (Arg + 40) * 256/192
LC30C: FCB 254 ; If in Open Lp => 25.4 Sec after
; closed loop then Divert
; Cal = Arg * 10
***************************************************
I hope this clears up anything concerning Diverter valve operation and the computer.

dctrumpet

iTrader: (10)

How does one become a senior member? Member? etc? I am a junior, LOL

Fast355

iTrader: (2)

A thing that crossed my mind though, when you removed the valve, I am assuming that you added a block off plate. Did you use a new gasket? Maybe the gasket is bad and allowing EGR to occur without a valve. You could also have a substantial vacuum leak. Most stock calibrations will not open the EGR valve until 1,000 rpm, 2-3% TPS, and 2-5 MPH which is why I know the EGR is (99.999% certain) not your problem.
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That proves nothing! That is all TPI stuff. TBI air control is much different. Even mentioning LV8 means TPI. From the looks of it the TPI is either in downstream (Conv) or Divert mode after warmup. The upstream (exhaust manifold) is only used during warmup. Otherwise the added O2 will easily give the 02 sensor false lean readings that will make it run super rich. From an emissions/economy/power stand point there is no reason GM should or would have programmed it that way. The air is either downstream or diverted with a warm engine.

dctrumpet

iTrader: (10)

This is the current chip bin. I have burned several chips with the help of others, but obviously still very new to it.

Here are the Constants/Scalars for the EGR .

EGR - Max added SA 3.87 deg
EGR - Off (temp) 177a/d inverse
EGR - On (temp) 165 a/d inverse
EGR - Off (speed) 218
EGR - On (speed) 230
EGR - Off (TPS) 1.95 %TP
EGR - On (TPS) 3.52 %TP
EGR - off (low MAP) 16.30
EGR - On (low MAP) 19.99

Definitely used a block off plate with new gasket and some RTV sealant.

cheese_kake

It goes by how many posts you have, Im not certain at which number it changes over tho. But it goes to "senior" somewhere below 1,000 I think maybe 500 or so.

BMmonteSS

If brian at tbi chips burned the chip then he disabled the EGR. So just like Fast said the EGR is not the problem unless your adapter plate is leaking exhaust gas into the intake. I would look at your chip as the primary source of the problem. I assume you have some sort of logging equipment? If so what does the ecm think is going on when it idles rough? You'd be surprised how bad your car will run with something simple like an CTS being unhooked.

dctrumpet

iTrader: (10)

Burned new chip. Found that my distributor cap was a problem. Wasnt before the removal of all the smog stuff, but i took it off and saw a crack. Oh well, lol. I didnt even remove the cap at all, but somehow it obviously got damaged.

It is running better but i still have a vibration that we cant seem to find. It's been there since the installation of the engine.

So, off to another diagnostic path. Thanks guys.