I have a 1990 camaro rs, the previous owner did a tbi to tpi swap on the 305 and Im wondering why some stuff is missing. The car seems to be running a bit rich and I can't pass a etest. I don't have much info on what was done during the tpi swap other than it came from a 1991 firebird. I don't see the egr valve and canister and was thinking that mite be the culprit. In the last 2 weeks the car has been to 2 shops and $1500 worth of throwing parts has been done but still running rich. I replaced the cat twice it now has a walker hiflow, I changed the 02 sensor, temp sensor, thermostat, pcv valve and cleaned out the baffles. The only thing I keep failing on the etest is at idle on the 2speed test. I can't find any mechanic that knows much about these cars and because of the tpi swap it confused the last 2 I took it too. Any help or direction would be much appreciated I'm brand new to this forum and not the greatest on computers so please forgive me in advance.

 

You need to post your location...
I'm your guy but if you're not in Ca. I can't help.
I have done a lot of those.

 

It would be helpful if you post your state's pass/fail numbers and the numbers that your engine is producing.

A list of the parts that were replaced would help as well.

 

I'm in Canada, Windsor Ontario.

first off its a 2 speed idle emissions test the 2 things out of 6 that I'm failing is on the at idle part HC(ppm) limit at idle is 200 my reading is 644 and the other is CO(%) limit 1 my reading is 1.33

 

The stuff I have replaced and done in the past few weeks is as follows:

New wires and plugs, O2 sensor, walker hiflo cat(changed cat twice first one was crappy), pcv valve(cleaned out baffles), coolant temperature sensor, thermostat, fresh synthetic 5w30, spectre air filter.

I cant find an egr valve or canister so I believe an egr delete was done when tpi swap was done. I'm thinking injectors next

 

My personal emissions failure horror story resulted from 305 injectors and ECM left in place when the PO swapped in a 350. Obviously, caused the car to run lean. It was driveable but failed emissions numerous times.

You have the opposite problem running rich, but I could see it being a similar issue (for example, your PO grabbed a TPI setup off a 350 motor and just bolted it to the 305 block). I would suggest checking the injectors and maybe taking a look at the ECM itself to make sure both are appropriate for a 305 TPI T5 car.

Speculation here, but if the EGR delete was poorly done that might cause problems as well? IIRC the whole point of forcing air into the exhaust is to more thoroughly burn hydrocarbons before they reach the tailpipe. Maybe someone can confirm (I don't know exactly what impact an EGR delete would have on emissions).

I wish we had the idle test out in Colorado - they put the car up on a dyno and run it at a variety of speeds for a fairly long time.

Best of luck!

 

The egr allows exhaust gas back into the engine to lower combustion temps which in turn lowers the emissions

 

What are the other test numbers and their test limits? It helps to see all of them; %CO, %O2, HC, CO and NO.

Example (My 440k mile Acura Legend ):


I'd concentrate on the mixture first. Connecting a scan tool to see what the ECM is receiving from the O2 sensor and what/how the ECM is trying to adjust the mixture at both test conditions might be helpful.

The EGR valve is located under the plenum. Simply put, deleting the EGR function would effect combustion chamber temps by raising them and would cause the NO numbers to be elevated at road speeds other than idle (the EGR doesn't operate at idle).

I recall reading someplace or someone telling me that excessive EGR will cause misfire and partial mixture burns (elevated HC).

 

HC(ppm) 2500 rpm limit 200 reading 104 pass, CO(%)limit 1 reading 0.41 pass

Dilution% limit 6 reading 15.41 valid

Idle: HC(ppm) limit 200 reading 644 FAIL
CO(%) limit 1 reading 1.33 FAIL

 

I'm wondering if I have no egr valve could I simply put one on or if its off because it wont work with my tpi setup

 

Which scan tool works for my maro odb1?

 

Was a custom tune done? The reason I ask is that there isn't a stock GM tune available for that combination. An L03 is nothing like an LB9 or L98 f-body engine. Cam, heads, exhaust, all different.

RBob.

 

thats what I was thinking and asked the last mechanic, he had no idea on how to tune her. How should I go about looking into getting a good tune.

 

My biggest problem is that I'm not a mechanic, my skills top out after brakes,shocks,car audio the basics. I can't find a good old school mechanic or even a speed shop in my city to get my maro in top running condition. Been thinking about ripping out the 305 and t5 and looking into a modern 4.8l or 5.3l setup just don't want to cause shes a low mile car(80xxx).

 

Just going by these symptoms and nothing else (like knowing exactly what was done when the engine swap was made), it seems like your converter isn't staying hot at idle.

Are you running the stock manifolds or headers?

Edit:

Two more things:

1. Does the test results give you a O2 (oxygen) measurement?
2. Are you still running the AIR pump?

 

there is no 02 measurement on testing. I believe the stock manifolds not 100% and no idea about the air pump I'm going to check tomorrow.

 

I'm going to take some pictures and post them maybe a few visual shots somebody mite see something that don't look right.

 

I got some information i spoke with the previous owner. The tpi setup was from a 91 350 car but he bought the computer and injectors from a 305 car. He removed the pollution pump and welded egr up.

 

anyone know if a standard GM tune would work with that combo?

 

Sounds like you need to lean out idle in the tune. moates.net has the extreme aldl cable, g1 ,sst27c512 , and burn 2.you. An download tunerpro rt to monitor fuel trim. With the Tbi to Tpi swap you should verify that the po put the serial data wire at the aldl from e to m.

 

thank you, I asked the po about the serial data wire hes not sure, another thing I'm looking into then I will order the the stuff from moates.net and go that route.

 

You can look at your aldl under the dash drivers side.


It's easy to use a paper clip to release the tab and pull the wire out the back.There maybe a plastic lock piece that needs to be removed first.
You need the $8d adx file for tuner pro rt.
http://www.tunerpro.net/downloadApp.htm
http://www.gearhead-efi.com/Fuel-Inj...Information-8D

 

You may want to get a hdr1 too. The hdr1 will allow you to reflash the eeprom without removing it from the g1 piggyback adapter.