What other mods needed with ported heads to get the codes cleared?

[jimtash]

I'm asking because the CEL is on telling me that the car is running lean at some points (code 41 and 91) with no vacuum leaks. I've got a new fuel pump on the way because this one is getting really noisy and think it's the original as well with over 300,000 miles on it now but other than that, what else should I do? PCM tuning? The car also has the Magnaflow pipes on it and the Borla exhaust. No other mods to the intake system except for a K&N.

 

[LOUDSHO92]

It should run fine. You have other issues. Maybe bad O2s?

 

[rocket455]

i have the same issue with my 92. is that all you did is just port the heads? like you tore it apart with no issues on the car, did the heads, then put it together and had this issue? help me help you

 

[deercrusher]

While you wait for the fuel pump to come, you could just use a fuel pressure gauge and test it to see if you are getting proper pressure. At least you'd have it narrowed down that far. How's your fuel filter?

Higher flowing heads won't allow so much air to flow that the fuel system on the sho can't compensate. Pump and injectors are supposedly good enough to keep up with even a couple of pounds of boost on FI setups.

 

[jimtash]

i have the same issue with my 92. is that all you did is just port the heads? like you tore it apart with no issues on the car, did the heads, then put it together and had this issue? help me help you

Yep that's all I did. No issues related to it running lean beforehand. KOER test revealed no lean condition during the WOT portion of it (code 43) and the cylinder balance test results are normal. The CEL actually went out on its on once if that's an indication of anything. And it usually won't appear until 10 minutes or so of driving after start-up.

O2's are brand new as are all the gaskets.

 

[jimtash]

While you wait for the fuel pump to come, you could just use a fuel pressure gauge and test it to see if you are getting proper pressure. At least you'd have it narrowed down that far. How's your fuel filter?

Higher flowing heads won't allow so much air to flow that the fuel system on the sho can't compensate. Pump and injectors are supposedly good enough to keep up with even a couple of pounds of boost on FI setups.

Fuel filter is relatively new and the injectors have been refurbished and flow tested. They are operating good considering the clicking noise they make. I will definitely take a look at the fuel pressure.

 

[rocket455]

i was doing some research about this since im having trouble too with this. i found this on TCCA
http://www.taurusclub.com/forum/index.php?showtopic=56831&hl=136

so maybe try unplugging the connector at the MAF. and if it runs worse, then its the MAF from what I understand from this. Can anyone else tell me if im wrong or right?

and what is the pressure at the rails supposed to be?

 

[jimtash]

I disconnected the MAF and the RPM's fell immediately. As soon as I reconnected, the engine started running fine again.

 

[rocket455]

well from my understanding, that is a good MAF. Im stumped on your car as well as mine. Does your car have EGR?

 

[jimtash]

well from my understanding, that is a good MAF. Im stumped on your car as well as mine. Does your car have EGR?

Nope, no EGR.

I think it's more of a fuel issue than anything else. The noise the pump makes fluctuates with the engine. It was noisy before but now it's getting pretty bad.

I really appreciate your help.

 

[rocket455]

well a noisy fuel pump means it is going out. that may or may not be causing your car to run lean as the pump isnt able to supply enough fuel at times. so as soon as we figure out what it is supposed to be, you should check the fuel pressure at the rails. and if the time comes and by the sound of it, you may have to replace your fuel pump, here is a link to make an "access door" so you can get to the pump by not dropping the tank http://www.shophoenixproject.com/fueldoor/fueldoor.htm
i used a flat head screw driver and a hammer that i carved out 3 sides with and pulled the "door" back and then simply pushed it back down to seat when i was done.

keep me updated with any new developments with your car as i will with mine and hopefully we might be able to solve each others problems

 

[jimtash]

You got it.

 

[hawkeye18]

A bad fuel pump (or one that is going bad) will cause a lean condition like a champ. I'm willing to bet good money you've nailed the source of the problem already.

The ECU is remarkably adept at adapting to different flow characteristics.

 

[rocket455]

is there a way to test a fuel pump to see if it is failing with out it whining? im trying to figure my car out too

 

[luigisho]

You can check fuel pressure at the rail through the schrader valve. Other than that noise, or lack thereof, is the only way to check it without removing it.

 

[ycode90]

My pumps are always loud .

 

[firstgen89sho]

Check your ground at the center of the intake valley, as that controls the O2 sensor heaters, I had that issue where the CEL would come on and go out, and in the end it led me to that I had no ground for the heaters, causing the O2's to cool off, going lean, fixed that problem and my CEL went away

 

[jimtash]

I think I figured it out. I sprayed carb cleaner around the intake and I could visibly see it bubbling up where it was leaking. The intake bolts have become stretched and won't torque down enough to get a good seal. In fact one bolt just kept turning until it broke so I fixed that and am just waiting on a set of new bolts to arrive. All this is because of the replacement silicone couplers on the runners not having any flex in them in addition to the replacement heads probably having different, yet small variations where the intake mates to them. In other words the intake seals perfectly with the old heads but not so well with the new ones because the couplers and runners became "fitted". The solution I think is to use new bolts and loosen the coupler clamps before putting the intake back on then tightening everything back up.

I'm still going to replace the fuel pump as well since I have it sitting here and the one in the car is more than likely the original. I'll keep everyone informed as to how it goes.

 

[jimtash]

Check your ground at the center of the intake valley, as that controls the O2 sensor heaters, I had that issue where the CEL would come on and go out, and in the end it led me to that I had no ground for the heaters, causing the O2's to cool off, going lean, fixed that problem and my CEL went away

Will do.

 

[the4biddendonut]

The solution I think is to use new bolts and loosen the coupler clamps before putting the intake back on then tightening everything back up.

That's how you should do it every time. Torque down the intake, then tighten the couplers to allow it to flex. Though I've personally never had a problem with the bolts before.