The Hawk failed emissions...

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Scott Chab
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The Hawk failed emissions...

Post by Scott Chab » Mon Sep 09, 2013 7:28 pm

And thanks to it being OBD1, the limited diagnostic data isn't helping any.

All of the data that can be read (MAF, MAP, o2 sensors, etc.) all show like they are fine but the PCM is dumping twice as much fuel into the motor than it needs. I'm beginning to wonder if the PCM is shot or if I have an internal mechanical issue.

:?

Edit: I was talking to a local shop and we came to the conclusion that I might have a bad or possibly several bad injectors. When I had the motor done, I put 36# injectors in (bad advice from someone I trusted) and the car wouldn't run for more than 10 seconds. I put a set of 24s in and it ran fine but I think they were maxed out or close to it and finally quit on me.

I ordered a set of 30s and I'll hopefully have them by the weekend.
'94 Hawk #110
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96AZHAWK
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Re: The Hawk failed emissions...

Post by 96AZHAWK » Fri Sep 13, 2013 1:02 am

Is it indeed the PCM commanding the extra fuel or could it be a bad regulator dumping it into the intake?

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Scott Chab
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Re: The Hawk failed emissions...

Post by Scott Chab » Fri Sep 13, 2013 11:12 pm

Can't tell where the extra fuel is coming from. I'm changing the plugs (Yuck!) and o2 sensors tomorrow to see if that does the trick and then I'll do the injectors and have to send the PCM out for a tune again since I can't find anyone to tune an OBD1 car.
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96AZHAWK
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Re: The Hawk failed emissions...

Post by 96AZHAWK » Sat Sep 14, 2013 12:45 am

Other than O2's and injectors, I would check the regulator. Are you running a stock one? pull the little vacuum hose off the top of it and make sure there is no fuel in that line or more so coming out of the regulator there.

O2's should be able to be read by a scanner and ranges and switching should be noticeable.

Injectors, depending on the style... some stick open, some stick closed.

Good luck, and if you figure it out, please post up the results! hahaha

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Scott Chab
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Re: The Hawk failed emissions...

Post by Scott Chab » Sat Sep 14, 2013 11:02 pm

Got the driver side plugs changed today, the old were fouled ad hell. (Probably from a pervious exhaust leak) I just don't have the patience or the skinny forearms to get to the passenger side plugs so I threw in the towel and am taking it to a shop to have the rest changed next week. Also noticed a header bolt that had backed out. I didn't hear any ticking/tapping so I don't think it was leaking but...

Also got both o2 sensors changed.

It is definitely running leaner but I'm not sure if it's enough to pass emissions. The regulator never popped into my mind. It's worth checking out.

One thing I know is that the car s running like a champ. Pulls hard in every gear and there is no hesitation what so ever. 8)
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Re: The Hawk failed emissions...

Post by Scott Chab » Tue Sep 17, 2013 9:54 pm

Got the rest of the plugs changed and it is still running rich. FPR is fine but the motor won't hold pressure when it is shut down leading me to really believe it is the fuel injectors.

Got a new set on the way and I'm almost positive this I going to solve the problem.
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TTOP350
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Re: The Hawk failed emissions...

Post by TTOP350 » Thu Sep 19, 2013 9:42 am

Did you have the PCM changed when you put the bigger injs in it? If not that in itself will dump waay 2 much fuel.
What all is done to the motor?
Also if you haven't, change the oil b4 you go in for testing, it's gotta be full of fuel.

You can run stock injs on a stock tune with a modded motor, just use your head and don't be running it hard until your ready to tune it for bigger injs.
Always looking for SLP/Firehawk parts for 3rdgen birds.
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Re: The Hawk failed emissions...

Post by Scott Chab » Thu Sep 19, 2013 2:29 pm

TTOP350 wrote:Did you have the PCM changed when you put the bigger injs in it? If not that in itself will dump waay 2 much fuel.
What all is done to the motor?
Also if you haven't, change the oil b4 you go in for testing, it's gotta be full of fuel.

You can run stock injs on a stock tune with a modded motor, just use your head and don't be running it hard until your ready to tune it for bigger injs.
The car was dyno tuned with 24# injectors. I bought 30# injectors but never put them in because I can't find anyone to tune an OBD1 car. I returned them and got a new set of 24s today and will have them in by the end of the weekend. I also already have oil and a filter and will change them before I got through inspection.

The motor is a 396 stroker, ported/polished LT4 heads and intake, custom cam and long tubes.
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Re: The Hawk failed emissions...

Post by Scott Chab » Tue Sep 24, 2013 9:41 am

Passed inspection with flying colors. Had to be the injectors.

8)
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