Occasional power loss??

[bigbadfords]

This may be hard to explain what is happening but I will do my best here. My car runs great about 75% of the time, but occasionally has very little power and doesnt seem like it has a miss or anything like that. I will give an example to try and make it easy to understand. I can be cruising at 55 mph with rpms at about 2000 on flat road, if I want to gain speed and push the pedal down, the car will downshift and rpms will raise to about 2600, but the car will either gain no speed or very little, feels almost like I am towing something or I am driving into 120 mph winds. I noticed that it seems like it mostly does it in "warmer" temps, when I leave in the morning the air temp is about 50-55 degrees and it never really does it, when I come home from work in the afternoon and the temp is 70-75 degrees is mostly when this happens. I am thinking its either a sensor of some type or my K&N cone filter is getting too much warm air combined with the engine heat. I just replaced fuel filter and made no difference. Any suggestions are greatly appreciated. Thanks guys.

 

[stephen newberg]

Sounds to me like the IMRC is occasionally failing and as a result the secondaries are not opening properly. The gears inside the box for it are plastic and when they start to fail, it can for a while be inconsistent in its failure mode.

pax, smn

 

[bigbadfords]

Can you tell me where the IMRC is located on these cars? I am not seeing it anywhere, unless I am just overlooking it...thanks

 

[Liquid_force]

Remove the vanity cover, it will be the ~6x6 box staring you in the face. 3 bolts hold it in place, and the plastic linkage at the right side of the runners, oh, and the electrical connector. The box can be easily opened and you'll find a little plastic gear that is known to get brittle and break over time.

From what I've read the only ways to repair it are either wire the butterflies open, or find a JY imrc that's not broken. Not sure if they're still available from dealers.

 

[stephen newberg]

That mainly covers it. Wiring the butterflies open is pretty easy, causes no problems, and allows you to dispense with the entire box and connections, plus all the problems it tends to bring. Cheap, too.

pax, smn

 

[escortlvr]

Does wiring the secondaries open cause a CEL ?

 

[bacernate]

I fought this for the 3 years I owned my 97. It came with an sho shop cold [oh I mean hot] air intake. The gen 3 is very sensitive to heat. I looked at the scanner when it was happening and the intake air temp sensor was reading 150+, so I would recommend getting a stock air box and porterizing it. Also you could see if Paul [shoz123]has any more phenolic spacers for the intake.

 

[stephen newberg]

Does wiring the secondaries open cause a CEL ?

Yes, but it can be turned into a one time thing by just unplugging the battery for a bit and letting the system rest after it happens. Then gone for good.

Bacernate's suggestion of going to a standard air box and then some form of Porterized cold air intake from the inner wheel well instead of a cone filter just under the hood is a good one too, regardless of which of these is the cause of your problem at this time.

pax, smn

 

[bigbadfords]

What exactly does the phenolic spacer do? I actually just sent out a check to paul for a stock air box that he had laying around, just wondering what the phenolic spacer does?? Thanks guys

 

[bacernate]

It's a plastic spacer that goes in between the intake manifolds to keep the heat out of the upper intake.

 

[Ian Macoomb]

Paul might not have any but I know who does.

 

[bigbadfords]

Hey guys, I took the imrc cover off and checked the gears inside, all the gears seem to be fine. Does this mean that the imrc is most likely not my problem or could it still be the problem even though all the gears look fine? Thanks

 

[SHOZ123]

I have two sets of the spacers left. They are insulators and work great.

 

[stephen newberg]

Hey guys, I took the imrc cover off and checked the gears inside, all the gears seem to be fine. Does this mean that the imrc is most likely not my problem or could it still be the problem even though all the gears look fine? Thanks

If the gears and the connecting wire going out of the box all look good, then the problem could be with the butterfly valves themselves being sticky, which is not uncommon, or it could be something else completely causing your problem.

pax, smn

 

[BamSHO]

Try this. Open hood and start car and rev motor up and look to see if the IMRC is opening up. Mine went bad and when i would start the car up they would open up. End up replacing it, I could here the gears grinding, but still couldnt figure out why it failed open.


Brian Michael
98 silver Gen3

 

[bigbadfords]

Do any of you guys know what RPMS the secondaries are set to open at?? and will they open at this same RPM regardless of the transmission being in park or in drive gear??

 

[escortlvr]

It's like 3k RPM's range and they will open up in park.

 

[Liquid_force]

I think I read 3400.
Not sure if that's right, but that seems like the point you can hear it -- at least something a little higher than 3000.

 

[bigbadfords]

Guys, do you think the imrc is possibly still my problem even though this is happening at rpms lower than the 3000 to 3400 range in which the secondaries are suppose to open. I have this power loss happening even at 1800-2500 rpms, not just higher rpms. Is a tps (throttle positions sensor) a possibility at all ?