LoTu5

I recently replaced the old stock 23 year old injectors on my 415. Car is running well, except it is now letting out a high amount of fuel fumes.

I've pulled the plugs and all except one look to be burning very well. One is looking a bit sooty.

Question, did the engine just get used to the old injectors and now need setting up with a tech 2? (is that what they use)

A friend has a scanner and once he is back off holiday we will connect the scan to see what is happening.

Or could it be a sensor or something else blocked.

The engine should have plenty of air getting in as it has had maximum porting, runs headers and 3" B&B

Thanks in advance.

Goldcylon

What brand injectors? May be time for a charcoal cannister change as well on the paassenger rear side

Dynomite

If this is a 1990...then charcoal canister is under drivers side head light
You 1991 charcoal canister is under passenger side behind rear wheel panel.

This little difference between 1990s and 1991s makes the Plenums not interchangeable (unless you want to plug and create different vacuum ports) but Heads, Injector Housings are interchangeable. And even mixable (1990 Heads on 1991) with some minor modifications to Injector Housings PCV.

Rkreigh

have the injectors been sitting a while or are they new? sounds like that one cyl might have an injector hanging up. what brand of injector and what is the rated flow (lbs). unfortunately new doesn't always mean "good" might have a cantankerous one in there.

also check that they aren't leaking. you can pressurize the fuel system and pinch the return hose with vice grips and see if it holds pressure

o rings might not be seated properly. it's pretty tough getting them all to line up and go in right (took us 3 tries at gordon's school, but we got er dun)

good luck!

Goldcylon

Yep those darn 90s a lot of one ofs. Cliff is correct the charcoal can is under the passenger headlight. I was wondering if these were new injector or rebuilts.

LoTu5

Injectors are new ACCEL Fuel Injectors 150821 and rated at 21 lbs/hr.

http://www.summitracing.com/parts/acc-150821

By the way it is a 90 car. When fitting the injectors I found the easiest way to clip them into the rail was the first ridge of the two. That way they were easier to push into the injector housings.

Think I might take the plenum off again and turn the ignition key to just before starting to see if there is any leaks. Also check to see if they are seated ok.

I always take my time and never rush things and thought they went 'home' OK. However practise does make perfect.

Thankyou all for your replies.

Goldcylon

Well the Accels or the RCs are the best in my book. Just put a fuel pressure guage on the rail and see if she holds. Will have you answer real soon. Also no joke its time to replace the charcoal cannister after over 20 years of service.

bbgs211

Gold cylon...you really seem to know your ZR1's! I just purchased a 95k mile 1990 that runs fine, a little rich though. What does the charcoal cannister do and can you replace the innards or do you have to replace the whole unit? someone also told me to replace the MAP sensor if it's the original, that a bad one will make it run rich also.

Goldcylon

Its part of the emission system and captures fuel vapors. Over time the charcoal become saturated and will break down. A few owners has discovered charcoal bits injected into the filter of their secondary systems before the control valve. They are fairly easy to find the last one I bought I got at Rock Auto. As to tearing them apart they are priced at a point its not simply worth the effort.

GC

scottfab

The charcoal canister will not cause a rich condition. A faulty O2 sensor will.

Goldcylon

A faulty saturated canister will allow a fuel smell to be released around the car. Its a part of the emissions system

XLR8TIN

Mine is removed, all good

Goldcylon

No fuel smell at all ?

LoTu5

Yes I am sure my charcoal canister has been disconnected. I run headers now.

I have one 02 sensor and will play around with replacing one side at a time to see which one is faulty.

FU

Did you check if the fuel rail hold's pressure ?

Paul Workman

Bob G had a new, out of the box bad injector that would not shut off. A fuel rail pressure test would indicate such a problem, and doesn't require pulling the plenum (not that pulling it is a big deal).

OP: hook a fuel pressure gauge to the Schrader valve on the fuel rail. Then roll the ignition switch to ON, w/o starting the motor, and then turn it OFF. The pressure may spike, and then settle to mid to low 40s with the switch OFF. the pressure should hold to within a PSI for 10 minutes or so, long as the injectors (and the fuel pump check valves) are working.

And, having it scanned might shed some light on the O2s. (My scanner has paid for itself several times over - used on my Vettes and other vehicles too. Best tool in my box for troubleshooting.)

HTH,

P.

LoTu5

Thank you all for your input. A couple of things.

1/ I can not get hold of any AC Delco or Bosch 02 sensors without a wait. However I can obtain off the shelf (NGK)NTK OZA446-E8 Lambda sensors. Cross referenced from the Delco's and Bosch's.

Has anyone used these sensors?

2/ Not sure what a "Shrader valve" is although at a guess it's obviously on the fuel rail poking out of the Plenum area.

I don't have a fuel pressure guage, but have a vacuum kit in my possession. would this suffice ?

Goldcylon

1. Id wait Ive only used AC Delco or Bosch
2. Yep right off the fuel rail on the passenger side
3. No you need a fuel pressure guage.

LoTu5

Sorry, are you saying you have used NGK ?

I will get hold of a Fuel pressure guage and check the injectors.

Thank you for your help.

Goldcylon

Used both AC Delco and Bosch no issues, Never NGK