With much hesitation, I tore into my virgin-perfect, 22,600 mile '88 IROC L98 last weekend. I'm thankful I did, as I had THREE seperate leaks from the intake gasket...I only knew of one for certain, which is why I did this in the first place. Thankfully, I had a GM master tech with me for the tear-in, so it went nice and smooth.

After replacing the injectors with Southbay Bosch IIIs, the thermostat, cap and rotor, and PCV valve, I fired her up. No SES light, but there was a little bit of hesitation that smoothed out a small amount after 30 seconds...then I shut it down. I changed the oil, added coolant, dropped it and parked it.

I started it again yesterday to take it for a ride. Backing down the driveway, I could feel a significant bogging sensation. As I tried to accelerate down the street, off idle it almost died, but smoothed out with RPMs. By the time I got it to the gas station a few miles away, it acted fine. I filled it up, took it up on the main drag and wound it out to 4,500, and it ripped I am very happy with the performance...the injectors felt like they added some real SOTP improvement over my 23 year old injectors.

Any idea what could be causing my cold issue, though? Could it be a cold start injector issue? Everything else is fine, and overall I'm very pleased with Southbay's service, and the product they provided. The injectors fit great...just too bad they're yellow instead of black! They stick out in an otherwise 100% original engine bay.

 

Youre lucky you can drive yours down the street. I installed some Bosch III last weekend and now the engine sounds like its running on 3 cylinders.

Can I borrow your GM master tech?

 

Reading your post reminded me of my own issue. Indeed, I am pretty lucky it all went as smoothly as it did. As it stands, the car is more fun to drive now, even with the headache.

Listen to the advice on here, and more importantly, don't sell the car (saw you comment on that) and don't give up hope. You'll figure it out...there's only so many things it can be!

 

Hi Jason,

When the car first starts it is running on pre-set values and not listening to the sensors, right. Sounds like you may need an adjustable fuel pressure regulator (unfortunately it won't look stock) to tune the fuel pressure. Once the ECM starts listening to the sensors it is able to compensate for the rich/lean condition (via the BLM), but at start-up it cannot.

Hope this helps.