Engine Pro-m Install With Intermintent Check Engine Light

[RangerJoe]

Hey guys,

I just installed a used Pro-M 80mm meter and filter on a home made power pipe, calibrated for my injector size. I am now getting an intermittent CEL that only comes on after a pull the rpms up and let the car pull the motor down (coasting after a pull). I have two theories:

1) The meter is no good
2) I am short one worm clamp and the intake tube is just slid onto the pipe until I can go by one (just test driving it right now). Could unmetered air be getting pulled in on the coast and causing the light to trigger?

I have pulled the codes, but they are all smog equipment related, and its all deleted, so that is expected. You can see where the clamp is missing in this picture.

Thanks for any help!

Joe

 

[RangerJoe]

Well, I added a clamp to the pipe, no help. It is definitely only coming on on decel. Someone throw me some suggestions.

Joe

 

[Onefine88]

Well i was thinking that you were getting unmetered air but you fixed that. Did you clock that meter at 12 oclock?

 

[Noobz347]

Recheck all electrical connections for a possible intermittent connection. Splices should soldered if any.

Look for codes associated with O2 sensors being out of range.

Recheck all vacuum connections since deceleration is when vacuum pulls most.

 

[RangerJoe]

I took the maf back out and cleaned the sensor. I also cleaned the connectors and tightened down all the clamps. I went for another ride and it started doing it about the third attempt. Then, after just a few times of doing it, it stopped. I tried about a dozen times to make it happen again, but no CEL. I have four codes. They are all emissions related, and have always been there. All vacuum connections are good. I'm hoping that the computer is just having to learn the new meter????

Going to take it out again when wife gets home. I'm not too optimistic that I am out of the woods yet.

@onefine 88, the meter is probably clocked to the one o'clock position.

Thanks for the replies.

Joe

 

[TOOLOW91]

I had an issue with my pro m not reading period. Someone suggested to me that i add some dielectric grease to the connector. I did and sure enough i have not had an issue since . I was able to see it on my pms not doing anything and then after that it came alive

 

[Noobz347]

Reclocking the meter a few degrees can sometimes help smooth out the inlet tract as well. I've seen that make a difference a countless number of times. Only applies if you've not already tried it.

 

[RangerJoe]

Didn't get to go back out tonight, but I will try both suggestions if problem persist.

Joe

 

[jka]

Try clocking the meter..because i think you are running lean ..clocking it should help but it will take time.

 

[RangerJoe]

Still haven't got back out to test drive yet, but I did finally find an old thread on coral where someone had the same problem. He was actually datalogging and said that when the throttle blade shut, the engine was still pulling air past the throttle blade and causing a lean condition. He said that it wasn't lean enough to really do damage, but enough to trigger the light until the computer could fix it and richer it up. If this doesn't go away, I'm hoping a tuner can compensate with more fuel and correct this. We will see.

Joe

 

[RangerJoe]

Btw, I am really impressed with how much better the car idles with the pro-m vs my old 76mm c&l. I never had any complaints with the c&l, but the pro-m did make a difference.

Joe

 

[Onefine88]

Btw, I am really impressed with how much better the car idles with the pro-m vs my old 76mm c&l. I never had any complaints with the c&l, but the pro-m did make a difference.

Joe

Agreed! I ran a C&L for years on my SSC. I thought the car ran fine until I tried a buddy's ProM on it. Wow I was shocked. When I built up my vert last fall/winter I went straight for a ProM this time around.

 

[jrichker]

Did you dump the engine running codes or just the codes with the engine off, ignition on?

 

[RangerJoe]

Did you dump the engine running codes or just the codes with the engine off, ignition on?

I went for another test drive today. I am positive its a lean condition. When the car is warming up, in closed loop (I understand that the car runs rich during this time) the light will not come on. Once the car reaches operating temp and goes into open loop, it will trigger the light under the decel conditions that I described above. I can override my electric fans and actually bring the car's temp way down by letting the fans run nonstop. Once the car gets really cool, I am assuming enough to throw it back into closed loop, the check engine light goes away again.

I pulled all codes, both KOEO and Key On Engine Running. Just so you can see, here are my codes, all emissions and evap canister related (gone when I bought the car, and these codes are always present).

81, 82, 85, 84
94, 44, 33

I have always heard that the C&L's make your car run rich, and I guess this is the case. Again, I am assuming that when this car gets a tune, more fuel can be added. Am I wrong about this? The car runs way better with the Pro-M and does not appear to be down on power at all.

Thanks again!

Joe

 

[RangerJoe]

J., do you happen to know at what AFR the stock O2 sensors and computer say there is a problem? I am just curious as to how close to danger I am flirting. Again, I can avoid the light all together by just clutching and letting the RPM's fall straight to idle, and I can live with this IF a tuner will be able to fix it.

Joe

 

[f8tlfiveo]

You should get a wideband on the car, not only for tuning purposes. You would know if the car is going lean for sure. 160$ will get you a decent unit

 

[RangerJoe]

You should get a wideband on the car, not only for tuning purposes. You would know if the car is going lean for sure. 160$ will get you a decent unit

I had one picked out a year or so ago, when I was considering nitrous. If I get a wide band unit, I think I would prefer one with datalogging capabilities too.

Joe

 

[f8tlfiveo]

I deleted egr and used that 5v signal for my data logging with binary editor. I'm sure there are other ways to do it just through the wideband.

 

[RangerJoe]

I talked with a tech from Pro-M. He asked me to measure my voltage at 1K, 2K and 3K rpms and email him the results. Here is what I came up with:

1K = .89
2K = 1.30
3K = 1.59

I don't know if these values mean anything to anyone besides a pro-m employee, but I thought I would throw them out there and see if anyone had anything to say. I just emailed the tech, so hopefully I will know something tomorrow.

Joe

 

[jka]

Have you checked the maf sensor wiring harness for shorts? Because it's not putting out enough volts if i'm understanding right from the numbers i'm seeing.