Lean Condition after MAF and Injector Upgrade

[JT93SC]

I just upgraded the SC to 36# injectors and a C&L 76mm MAF with the orange sampling tube. I'm now getting a bit of hesitation when I get on it and my Check Engine Light comes on when I accelerate. The codes are

172,176 - Lack of Oxygen Sensor(HEGO) Switches - Lean Right Side(172) - Lean Left Side(176)

181,189 - Fuel System at Rich Adaptive limit at part throttle - System Lean - Right Side(181) - Left Side(189)

I know I was running lean with the stock 30's and the stock MAF after results from the AFPR test at Jeffs last year, but I didn't have any check engine light at that time. I have the full Magnum Powers upgrade - MPII, MP intake plenum and 85mm throttle body.

Have I leaned the car out more by opening up the Intake with the 76mm Maf or is it at the point I need a Tuner?

Any help would be appreciated.

Thanks - Jim

[Bill McNeil]

Jim,

Nice to hear from you again!

Firstly, are they Ford injectors or aftermarket? Could be a pressure issue.

Are you running a stock regulator?

I can tell by the sampling tube colour that you have the correct tube, so don't worry too much about that.

A tuner would almost certainly fix this problem, but adding some fuel pressure with an AFPR could also.

Let me know on the injectors first and foremost.

[JT93SC]

Hey Bill - Thanks for the reply. I reallly wanted to make it out for a Dyno or the V6 challenge with you guys, but I thought I better take it easy with this Lean condition. I bought the injectors from Jamie Hiscoe, and they were the Blue top Ford injectors. I put new O rings on all of them. I also have upgraded to the 190lph fuel pump.
I am running the stock regulator. I know on another thread that it was mentioned it might be a better idea $ wise, to go to a tuner then to upgrade the regulator. Any thoughts?

[SeanMatteson]

Jim,

I suggest you start by gathering some fuel pressure data. If you find that the fuel system has sufficient pressure under various load conditions, then you can rule out the FPR. Are you running some kind of a cold air intake system? If so, you need to know that the C&L MAF's are pretty sensitive to airflow turbulence at the sampling tube. Many of us running the MAC CAI have resorted to rotating the MAF about 90 deg towards the fender in order to move the entrance to the sampling tube away from the turbulence created by the bent in the pipe just before the MAF.

I hope you get the bugs worked out soon!

Cheers,

Sean

[lazybird4pt6]

Might sound silly, but, when you installed the new MAF you DID disconnect the battery, right? The computer has to learn a whole new ball game with a new MAF and injectors, this is why I ask. You mention that it throws a code when you get on it - does the Check Engine light stay on or not?
If your computer is already at Rich Adaptive Limit i'd wonder if the fuel pressure just isn't enough. I did a similar (?) upgrade and everything was fixed with an extra 4 psi of fuel. No more detonation.
Also, the CAI theory is worth looking into.

[Bill McNeil]

Someone please remind me of something here before I propose a possible solution. The bigger the injector, the smaller the sampling tube, or the bigger the injector, the larger the sampling tube (diameter)?

Before I give out any wrong information, let me confirm this first.

[JT93SC]

Yea- I did the Computer reset twice now. The car ran real rough for about 5 minutes of driving after the reset, then it smoothed out. I thought it was OK but when you get to about half throttle and higher the Check Engine Light comes on. The light goes off when driving at slower speeds. I seem to get a bit of hesitation also when I get on it but then it seems to move real well at higher RPM.
I was actually thinking of swapping back the stock MAF just to see what happens. I might try that this weekend.

[JT93SC]

Ok just got some ideas from the C&L Tech.

During my install of the MAF i did a re-oil of the K&N Filter. (Ooops forgot to mention that). The tech asked me about this and suggested that it sounds like I might have an oiled up or a dirty MAF sensor. He suggested I use a Q-tip and some Brake cleaner to lightly clean the sensor wires. He said the conditions I mentioned sound like that's a problem. I will clean the wires tonight.

He also suggested if this dosen't fix the problem then I should do what Bill suggested and try and get a Fuel Pressure reading.

Bill - To answer your question about the Sampling tube sizes. The tech gave me this answer.

The Orange(36#) sampling tube I have has a larger Diamater size in the front of the tube and a smaller Diamater size at the back of the tube then the Gold(30#) Sampling Tube.

I'll post with results tomorrow.

Thks - Jim

[SeanMatteson]

Jim,

My car had similar symptoms recently, and it was a case of a dirty filament in the sampling tube. If you haven't already done so, try cleaning that up with some electronics cleaner in an aerosol can. If you've got a spare MAF, maybe you could try to swap in the electronics. Perhaps you've just got a bad MAF (electronics), and that's sending an inaccurate signal to the EEC.

Cheers,

Sean

[Bill McNeil]

Jim

Whenever I K&N or similar filter gets re-oiled, chances are more oil will be applied than necessary, or more that the paper can physically absorb. Even a new K&N from the factory has the ability to leave oil residue on your MAF wires, so this sounds like a very good possibility. The MAF and o2 sensors in particular are very prone to spitting a check engine light, and quickly, which would exlaplin the situation.

Did the tech suggest potentially using a larger sampling tube if this doesn't cure the problem?

Keep us posted...

[JT93SC]

Cleaned the Sensor wires with a Q-tip and brake cleaner. There was some streaks of black on the Q-tip after. Cleared the engine codes. I took the car out for a run today and the CHECK ENGINE LIGHT came back. Codes below

181,189 - Fuel System at rich adaptive limit at part throttle System Lean - right and left side

185 - MAF Lower than expected.

Looks like I will have to get Fuel Pressure Gauge. I noticed a fitting on the Fuel Rail on the Drivers side, is that where a gauge would screw on. Any suggestions on specific gauges would be appreciated.

Sean - You might have a point. Now that I have cleaned the sensor wire I'm getting a new code - Maf lower than expected. I don't have an extra MAF Sensor around but maybe I'll check the B-Boards for someone who has one for sale.

Bill - The C&L Tech didn't mention at all about changing to a larger sampling tube. He just said that the orange one was correct.

Thanks - Jim

[Bill McNeil]

Jim,

If I may suggest something that may be more effective. At Canadian Tire you can buy a product called "Electronics Cleaner", under the Motomaster brands name. It is roughly $6.00 a bottle, and is great for cleaning things like your MAF wires. You spray it just like WD40, and it evapourates without leaving any residue. This would thoroughly clean your wires to the point you can feel confident that is not part of the problem.

The computer is not getting a reading from the MAF, so it seems, which is why you are getting a lean condition. The computer is adding less fuel because because it thinks less air is being metered, and thus less fuel is required.

You may have damaged the MAF electronics, or harness during the installation/swapping process, which would explain this problem. If you could test the voltage output at the MAF, and try fluctuating the RPMs to see if it changes, that would determine if the MAF is fluctuating voltage properly, similar to the way the TPS works.

If you are getting MAF codes, you are likely wasting your time chasing the fuel pressure possibility. As with everything, it is what you touched that is the problem, not what you didn't. You swapped in a new MAF, you now have MAF codes, and a lean condition. All these problems are related to what you've worked on, so go after this issue first and foremost.

Good luck!

[JT93SC]

Looks like by listening to you guys I think I have the problem cleaned up. I worked on the Maf a little more. I found some Electronic component cleaner and I sprayed down the MAF sensor wires. I then rotated the MAF about 90 degrees. As soon as I got on it I could tell it seemed smoother. I tested half and WOT as often as I could today and not once did the Check Engine Light come on.
Look Ouuuuuutt - It's Dyno time. I still really want to get an AFPR reading and new HP and Torque numbers. I didn't have my Overdrive delete switch hooked up for last years dyno so it didn't hold 3rd gear. This year the Lentech is holding 3rd, I've got the bigger injectors and the 76mm Maf so I expect better numbers.

Guru's, I mean guys, thanks very much for your help. I really appreciate it and hopefully I can put my 2 cents worth in if someone ever has a similar problem.
I'll watch for a Dyno day, and if one isn't coming up soon I'll post when I'm going.

Thks - Jim

[SeanMatteson]

Jim,

That's great to hear! Hopefully, we'll be seeing some big numbers from you soon.

Cheers,

Sean

[the SPIN Doctor]

Jim,

This is great news! As always, whatever you changed...right? ;)

[Jason Wild]

Jim,
Good to hear the car is running well now see you at the Dyno:)

Can any one say
DYNO NIGHT?































I CAN:p