chevylu

Bosch Design III injectors for my 1990 L98 are on their way from Jon @ FIC: http://fuelinjectorconnection.com/sh...&productId=134. They should be here in a few days.

I ran across this article on changing injectors in an '87 C4: http://www.corvettefever.com/howto/c...uel/index.html.

A few questions for you guys who have been down this road:
Did you replace the fuel rail O rings as illustrated here? - http://www.corvettefever.com/howto/c.../photo_33.html
What's a good source for the runner-to-plenum junction gaskets?


For what it's worth, here is how I got to this point:
1990 Corvette 5.7L (VIN8 – L98) Completely Stock

Problem:
When it is cold, the engine consistently starts and runs reliably. After the engine comes up to operating temperature, when it is shut off, it will not start; it cranks but will not run.

Diagnostic Tests:
Following diagnostic chart A3 in the FSM
• No codes are present
• Good spark is present on all cylinders
• When the engine is cold, a noid light blinks reliably on cylinder 1; when the engine is hot, it will not blink
• When the engine is cold, a noid light blinks reliably on cylinder 2; when the engine is hot, it will not blink
• When the engine is hot, disconnecting the cylinder 2 injector will allow the engine to start; reconnecting it while the engine is running will cause the engine to stop running

Injector Resistance:
Cy- Cold - Hot
1 - 16.7 - 17.3
2 - 06.4 - 00.7
3 - 12.6 - 08.9
4 - 16.1 - 15.1
5 - 16.8 - 17.6
6 - 15.5 - 12.2
7 - 15.6 - 12.1
8 - 16.1 - 16.9

Conclusion:
Injector #2 shorts out completely when it is hot. When cold at 6.4 ohms, it will alllow the engine to start and run.

Time to ditch the Multecs and contact Jon for a set of replacement injectors.

AGENT 86

Yes, I got raped at GM for the fuel rail O rings.:o Do it, now is the time.
The gaskets are available at most auto parts places.

94z07fx3

Kudos for the excellent detective work.

schrade

I've got a set of Injector O-rings (sealed) from when I did my intake gasket swap - you're welcome to them for postage. I presume they're for the intake, and if they're the same for the fuel rail, Jon would know.

Mine is an LT1 tho'; I don't know if the injectors are the same.

I treat rubber parts with Trans-X; it really softens and swells the rubber. Whatever you do, DON'T put 'em in dry. I think Jon uses soap, and that might work better. It sure does good holding tires on rims, and window tint too.........

FICINJECTORS

when you get your injectors they will have the correct o rings for the L98.. We do not supply the o rings for the crossover tubes or the o rings for the inlet and return. I suggest getting them from chevy as too often the auto parts stores give you the wrong ones. The gasket sets can be bought anywhere. We like fel pro gaskets.

chevylu

Just to make sure we're on the same page, I'm referring to the fuel-rail O rings, not the injector O rings.

See http://www.corvettefever.com/howto/c.../photo_27.html and subsequent pictures.

The part number for the '87 L98 is 17111696. According to my local Chevy dealer this same part number is specified for my '90. $29.00 for seven. Ouch!

FICINJECTORS

thats them.. try napa.

floridamale

I just changed out my injectors 87 L98 for the Bosch lll but I didn't fine it nessary to open up the fuel rail if it's not leaking don't mess with it. I used dish soap on the seals for the injectors worked great.

RandyJ75

If your problem persists after the injector change, take a look at the Coolant Temperature Sensor, in the front of the intake by the fuel rails. If you remove it to make room to disconnect the fuel lines, make sure you do not wrap it in Teflon tape, as it will not ground, and will feed the ECM bad info.

Randy