Resolved 1GNT Failing Emissions, Is wrong ECU to blame?

[sniver]

Okay, I have a 90 Eclipse GS 2.0L non-turbo manual. My car is failing emissions but not by much, and I just learned from the previous owner that the original ECU was replaced with one from a 91 1.8L Eclipse automatic. The engine recently had the head redone and cleaned along with associated things. So I'm thinking something think this may be the cause. My guess is that since their different motors with different parts and sensors that this would not run optimally since fuel curves and ect and designed for the 1.8L. He said that he was told by a garage that it would work, but I'm not so sure, can anyone help me out?

 

[steve]

Okay, I have a 90 Eclipse GS 2.0L non-turbo manual. My car is failing emissions but not by much, and I just learned from the previous owner that the original ECU was replaced with one from a 91 1.8L Eclipse automatic.

It's not possible to run the N/T 4G63 with a 1.8L ECU. Somebody is confused.


Steve

 

[sniver]

I'll have to look into why he thinks a 1.8L's ECU is in there ,and what it really is, thanks for your insight

Say that the right ECU is in there and I have checked all sensors according to the Haynes manual and the whole intake was cleaned and head was rebuilt. The car is same as stock.

BTW- I've changed plugs, O2 sensor, coolant temp sensor, all fluids, valves, valve seals. The timing is correct and the car runs great.

Any other suggestions to help me pass?

 

[bomextalon]

well it would make it alot easier to help you if you posted all of the readings from your emissions tests.

 

[sniver]

I can't find the emission papers but the hydro carbons were over by about 30 points at idle and at 2500 rpm it was near failing but just passed, everything else passed but was in the upper range of numbers.

-I was told to give the stuff "guarenteed to pass" a try, it is a gas additive that cleans out the fuel system, Anyone know if this stuff will help ?

 

[sniver]

Well I guess i should post my fix.

The timing was advanced a few degrees so I set it back. Then since the car had been sitting for very long, I tried the stuff called Guaranteed to Pass in a full tank of gas and drove around for around 360 miles on that tank and an additional 140.

My readings on hydrocarbons went from 290 all the way down to 48. I guess my internals were really damn dirty and the advanced timing wasn't helping.

And the computer was the correct one, that guy was wrong.

 

[ilikespeeding]

Did you let your car warm up before you took it to emissions?

 

[sniver]

I left it at the station the night before and they did sometime the next day, so i don't know how warm they let it get.

 

[MarcVIII]

"They" did your e-check? I was having similar issues, but I'm a 2g AWD turbo and they were running the wrong test (OBD-I Hi idle test).

I replaced my EGR valve but cleaned out my old EGR valve with carb cleaner first. You gotta pull the throttle body (4 bolts and 2 coolant lines) and its underneath connected by two bolts. When you pull it check to see if the needle is up in the "open" position. If it is your diaphragm is shot and you'll need a new EGR. If not you can suck on the top inlet (4-5 breaths or use a vacuum pump, 20-25 psi should open it all the way) and the needle should go up to the top "open" position. When releasing the pressure the needle should decend to the "closed" position, blocking the hole. I still have my old one if yours is dead. I'm under the assumption that its good, but I wanted to eliminate all possible problems. PM me if you think this is your issue.

G2P stuff says it cleans up everything. If you wanna pull out all the stops- change your oil and filter right before the test and use an additive (Seafoam or Lucas both have done nicely for me). Add fuel treatment and fuel injector cleaner to the tank before taking it, use most of that tank (Lucas is good stuff again, Prestone makes a fuel treatment that removes water that I like OR you can add the G2P stuff you were talking about, has a 3000gt on its box so you know its good ). Warm it up to proper temp and that should do it if your cats good.

Keep in mind that idling is the cause of carbon build-up which is what's causing you to fail.

 

[sniver]

I think my EGR is good, but thanks for the offer..."they" were indeed the people who did my emissions testing. Before the 1st testing, my air filter, oil filter, oil, and timing belt were changed, my head was redone b/c of a broken timing belt (only 4 bent valves). It failed.

Then I got the title transferred from a relatives and I put new alternator,p/s, and a/c belts on, then I put in that g2p stuff with a full tank of gas, drove about 360 miles very aggresivly and then set timing back 3 degrees to the proper setting. Then got a 1/4 tank of 93 octane and I went to have it retested and it passed with flying colors (290->48 @Idle, limit=220). Thanks for the Info on the EGR and how to check it marc.