40.00 CAI problem??? too much air? not enough fuel??

bluestang2.3

New Member
Jun 29, 2007
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An interesting development has occured with the new CAI I installed. I was on the highway and noticed the tranny wasn't going into it's final OD gear (lockup) Since I have 287k on the original engine/trans, I thought, "Well, it's finally going out on me." Wrong. I pulled of to the side to check under the hood and noticed I had forgotten to plug in the MAF sensor. :bang: I disconnected the battery, plugged it in and waited ten minutes before reconnecting the battery. Now the trans shifts normally but I lose incredible power at WOT above 2500rpm. Off a dead stand still full throttle is great until about 3000rpm or in any gear at WOT. It almost seems as if it's now starving for fuel since it kinda surges. At ¼-½-¾ throttle everything is fine, but full throttle is useless above 3K. The new CAI is larger than the one I built so I'm wondering if I have to fabricate some kind of restrictor??? (seems stupid) Fuel pressure is fine at 35psi idle and 40 WOT. (I duct taped a gauge off the rail to my hood to check while on the road.)

I'm going to try and duct tape up the filter a bit and see if that helps. (again-seems stupid)

Do I now need stronger injectors? a "bigger" MAF, More fuel pressure? hmmm.

Any help would be appreciated-Jeff

287K and rising:)
 
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some testing results, still problematic

Well, over the weekend I did several experiments with the new CAI. Trying to figure out what the heck is going on. The MAF is clean with no clogging on the resistor/sensors. The ACT (Air Charge Temperature sensor???) I don’t believe I have one do I?? The IAT (Intake Air Temperature sensor has been deleted via a set resistor long ago. There are no vacuum leaks and other than a larger diameter intake tube, all is/was the same as before with the old CAI. Here are the results of my tinkering

1) I reinstalled my crappy homemade CAI and the car runs just as it did. Smooth idle, no hesitation off the line under all pedal positions, no power loss or bogging at all rpm ranges and normal transmission final gear lock up is good. MAF sensor is plugged in.

2) I put the new CAI back on, car idles smooth, no hesitation off the line and smooth acceleration under all pedal positions BUT… At any speed and in any gear WOT above 2500rpm causes bogs and surges. If I had to describe it, it’s almost as if I was pulling my boat, the engine is trying but seems to be starving of gas and surges as if sometimes it gets enough fuel. The trans shifts into final lockup and the MAF is plugged in.

3) With the new CAI on and the MAF unplugged I get a little hesitation off the line unless I floor it and keep floored or floor it real quick and back off to any other accelerator position. Idle is smooth and acceleration is great in all gears or rpm ranges, in fact pretty damn good. The trans will not shift into final lockup with MAF unplugged.

4) With the new CAI installed, MAF plugged in and duct tape around 75% of the outer portion of the filter, all is well with no hesitation, excellent acceleration at all positions and at all rpm ranges. Trans shifts normally into final lockup.

Now for the heavy load test—Da Boat

Scenario 1, 3, 4) With my boat hooked up, (1,470 pounds loaded) all results were the same as above with the exception of obvious loss of power due to the tow load.

Scenario 2) I have almost zero power at WOT and I mean almost zero, all other pedal positions are ok, but not WOT.

Conclusion as far as I can tell—Since the CAI isn’t forced or ram air and the engine will only “suck in” as much as it can take in, there is a fuel shortage with the MAF connected using the new CAI. Now here’s the kicker. How do I get more fuel in there? Can I trick the computer, or are we looking at bigger injectors, new higher flow MAF, stronger fuel pump? I’ve read on other threads about swapping a Cobra MAF and injectors for the turbo upgrade but those weren’t for the DIS dual plug engines like mine and may be too much for a N/A engine and will they even work on the DP DIS???

I could live with the MAF being disconnected and do the quick floor it from a stop to prevent the slight bogging, but I’d like the trans to lockup.

This really has me stumped and I’m sure there are geniuses out there that can help.
Here’s my engine stats for more info.
2.3 DIS Dual Plug EEC-IV
Custom header with full flow exhaust (not dual yet)
Thrush Turbo muffler
Accel supercoils
Capped off EGR
IAT resistor
CAI
I usually use mid grade 89 octane and Shell gas only.

Thanks you in advance for your help guys-Jeff
287K and rising:)
 
It's not a lack of fuel, you've got some other issue going on.

There's no way a a simple intake is going to cause a lean condition on a 2.3L N/A. Not enough additional air and the electronics just aren't that sensitive (it's not like an '05+ Mustang).

Sounds to me like you've definitely got some kind of leak behind the MAF. Unmetered air could be entering the intake and causing a lean condition, or the engine just doesn't know what to do with the unmetered air and it runs like crap.
 
I know the EEC-IV is quite simple and forgiving with it's operation. I've taken the intake tube off and looked over it with a fine tooth comb and don't see any leaks. I also used a sensor safe sealer just to make sure all connections are tight and sealed. I just don't understand why duct taping (restricting) the filter itself will cause a good run condition since obviously the filter is before the MAF and it seems the problem is after the MAF with the air metering. This is seriously driving me "Cuckoo for CoCo Puffs." My old CAI is PVC pipe with glued flanges and connectors that seem more apt for leaking that this one.

Thanks again and I guess I'll keep plugging away until I find the problem. Meanwhile, taped up filter it is.-Jeff

287K and rising:)
 
3) With the new CAI on and the MAF unplugged I get a little hesitation off the line unless I floor it and keep floored or floor it real quick and back off to any other accelerator position. Idle is smooth and acceleration is great in all gears or rpm ranges, in fact pretty damn good. The trans will not shift into final lockup with MAF unplugged.

I bet that your new CAI is screwing up the airflow signal for the MAF sensor. You might try rotating the MAF ~45 degrees at a time to see if that changes how it runs.

Slow95, that sig is hilarious! :rlaugh:
 
HORRAY!!!!

I FOUND IT!!!!! It was the MAF all along. Why it still works perfectly with the old CAI and/or the old OEM intake is well beyond my understanding but for some reason with this new CAI, it wouldn't work. I put a new MAF on it and everything is fine:) I do thank you for all the tips and suggestions in aiding me with this clustercluck of a problem and will try to help others here as you've done with myself.
I'll add a few pictures once my camera finally dries out.

Jeff
287K and rising:)