Emissions Test Failure - 88 Red Coupe

[Schrade]

Fuel pressure "Bleed-down times" have nothing at all to do with tuning. If there is any bleed down time, it's a maintenance problem, that is: if the fuel pressure drops after the pump goes off, then the injectors may be leaking.

Yeah - you're right again... maintenance and tuning have nothing to do with each other.

I'm schooled again. :BOW

 

[WTS]

Thanks for the reply !

I have found ACCEL Injectors locally and intend on installing them soon.

From what I have read these are a good choice.

Coupled with hard starting when warm, fuel pressure bleed down and wet plugs I think most of my problem is the injectors.

I will post the results of the next emissions test.

Regards

WTS

 

[Hib Halverson]

I should add that, if you run a pressure check and observe the pressure bleeding down, while leaking injectors is often the cause of this, there can be other reasons. Some of which are: 1) faulty fuel pressure regulator, 2) faulty ball check in the fuel pump and 3) internal leak elsewhere in the system.

The Service Manual usually has troubleshooting instructions which cover all of those.

 

[WTS]

Emissions Test Passed

116 BLM, as you know means the system is subtracting fuel. When you remove the PCV and its restriction, more air flows into the engine leaning out the air fuel ratios. The 02 senses that and the ECM begins to add fuel or, more exactly, leans the air fuel ratio less than before.

Do the fuel pressure test.

If you key-up and the pressure rises quickly to spec but drops soon after the pump goes off, it's possible you have leaking injectors.

Leaking injectors will cause the engine controls to skew the fuel delivery lean to compensate.

I changed the fuel injectors to Accel (24 Lbs) but the real improvement came with the replacement of the main Cat. In my case the two forward cats came apart and deposited via the Y pipes their contents into the main converter plugging it solid.

Needless to say the performance increase was dramatic subsequent to the installation of the replacement CAT..

The Car still runs rich but I have narrowed the problem down to a leaking Cold Start Injector.

WTS