Replacing Stock Injectors...

[6=8]

I recently put my GN "Back-on-Track" by fixing an overboosting problem. Hasn't run this nice in years! But due to the cloud of unburnt fuel that escapes out the exhaust every time I start the car (Leak-down) I think it is way passed due for injector replacement (Over 150,000 miles on these units)

I see that Kirban Performance offers a set of green stripes and lists them as stock/close to stock replacements (TOMCO 30 lbs) and I'm thinking about getting a set of these. They work out to approx 49.16 each.

Looking for opinions on this. I have a real need to keep things stock at this point (No room in the budget for AFPR, upgraded pump, matching chip, etc...)

Also, while i'm doing this, should I replace the injector harness to avoid re-connection problems?

Thanks for any advice!

 

[Jeff]

TTT

I'm interested too...

 

[DKREDT]

Replacing your injectors is pretty simple. IMO don't waste your money on a new set of 30lb green stripes... you can generally pick up a set for around $125... I think there is a set on the parts for sale section right now. If not, post in the parts wanted and you will come out $$ ahead.

I didn't have to do anything special with my inj harness... unplug the old and plug in the new....

HTH

Joel

 

[Racetronix]

You can send your injectors in to Racetronix for an ultrasonic cleaning, new tips, filter screens and flow test. Most Buick injectors come back to life after a good ultrasonic cleaning. If not you can seek replacements for the defective injectors. Buying used untested injectors are a gamble as you could end up with some that are no better than the ones you have now.

Inspect the injector harness for cracks in the wire and the seals on the connectors. If there is any indication of moisture getting in then it is best to replace it.

Racetronix manufactures replacement injector harnesses made with teflon wire which are highly resistant to gas and heat.

Jack
Racetronix
www.racetronix.com

? Are you sure it is not oil that is coming out of your exhaust?

 

[Jeff]

I have to agree...if the smoke at startup is bluish this is valve guide seals, not injectors. Are you losing fuel pressure when the vehicle sits after not running? This could also be an indicator of leaky injectors...

Racetronix...what do you charge for you injector service? I have what I believe to be original injectors in a stock '87 GN with 116K miles. I think they need some attention.
Jeff

 

[UNGN]

If you have $300 in your budget for injectors, have your stockers cleaned and buy a fuel pump. With 150K miles, the FP has got to be a hurting unit.

Get a 237 regulator from the junk yard and use $25 Thrasher chips. You can still go fast on a budget. The trick is to not buy a lot of parts you don't need.

 

[Racetronix]

Originally posted by Jeff
I have to agree...if the smoke at startup is bluish this is valve guide seals, not injectors. Are you losing fuel pressure when the vehicle sits after not running? This could also be an indicator of leaky injectors...

Racetronix...what do you charge for you injector service? I have what I believe to be original injectors in a stock '87 GN with 116K miles. I think they need some attention.
Jeff

The price ranges from $10-$15 each depending on what the injector needs.

- Viton or Buna o-rings
- Inlet filters / screens
- Pintle caps
etc...

Jack
Racetronix

 

[6=8]

Thanks for all the replies! This is great!

My "Smoke" during startup is definitly fuel related. Besides the smell, I have a Fuel Pressure guage installed under the hood. The pressure drop is not immediate, but after a few hours it is at Zero PSI, and this explains the hard start/unburned fuel sitch. Also, my idle seems to be very inconsistant... as high as 890, as low as 050 mv. I know these are typically all over the place, but this seems to be a little much. (I have installed a bosch, Echlin, and recently a new delco o2 sensor, my idle is still crappy, even with a nice .42v TPS/10-15 IAC with the same swings.) There are days when my idle seems to get surprisingly smooth, when I read the O2 counts, they range from 300 to 500. So it seems the injectors do smooth out once in a while.

I have a stock replacement pump which was installed earlier this year, replacing an ATR unit that had failed after 30K or so miles. Not bad, but noticed no real differences in performance. Besides, my stocker had at least lasted to 100K before I changed it.

I like the idea of sending the stockers in for cleaning. I was not aware of the relativly low cost. However, I would rather not take the car down and have to wait for the turn around. I may pick up a used set and send them in for cleaning/flow/inspection and when they come in, swap them out on a Sunday afternoon!

Good stuff guys! Thanks for the input.