Contour Enthusiasts Group Archives Forums Modifications Duratec Performance Dead IMRC box

I discovered while logging peak flow through the BTR intake that the secondaries haven't even been opening! I've had them propped partially open with the adjustment screw, so it's not as noticeable as it would be if they were completely closed. Heh, no wonder my peak flow numbers weren't very good.

Mr. Bill is out of the office today, but the local dealer wants $146 for a replacement. Ugh. I'm gonna see if I can fix it myself while I wait for Bill's quote.

Anyways, the point of this post is to warn others that may spend a fair amount of time running above the secondary engagement point that the box apparently does not have much of a lifespan under those circumstances. My 99 only has 51k on it, and there's no telling how long the box has been dead. No cel codes about it either.

I'm disgusted.

Dan Beggs
99 Cougar V6, running on 3.2 valves per cylinder

Email me Dan.

Bummer Dan!

You know, I've not yet heard of a OBD-I car having this problem..... :p

I think the vacuum based units are more reliable.

-Lance

Oh you funny man!

To be honest, I'm half-tempted to install a universal remote choke cable kit so I can open and close them while driving.

I just went out and wired them open while I wait for a server's downtime window to get here. I'll see if the peak flow numbers going home aren't any better.

dan

1 suggestion and 1 question.

Open the IMRC box and check under the circuit board to see if you have anything caught in your geartrain. It isn't unheard of for the straight end of one of the little springs in there to break and jam things up. (Mine was broken but was stuck to the motor magnets.)

If you upgrade to a MAF calibrated for a large engine (and more airflow) - won't you get a lower Vout for a given flow, causing your car PCM to convert to a lower flow number? If 5 volts out correlates to like 600cfm on the big MAF, and you get 5 volts out from say 300 cfm on the stocker, wouldn't 300 cfm on the big one give you like 2.5 volts? Obiously these are garbage numbers - but you could do a side by each of the two mafs. Say rev to 3000 rpm in neutral and compare measured #/min for each MAF to see how different they are. I really have no idea if that's really how the MAF works - but most sensors just give a set Vout for a given measured signal - and all the conversions / calibrations are on the mesurement tool side.