[rx750]

I have a 2nd generation rx7 which I dropped a 1990 5.0 HO engine into. It is completely stock except, I put an E303 cam into it, we took the air pump out (there was no room for it), K & N air filter, aftermarket H-pipe and mufflers. The problem I'm having is a real bad lope at idle, and when I come to a stop the car wants to die. Sometimes it idles ok, other times it's really bad. The lope seems worse when I have accesories turned on. (rear defogger, headlights, etc.) What can I do to fix my problem?

thanks for the help

 

[lxarlo]

i dont think that would be caused by the cam because that cam is pretty mild, it may be your mass airflow meter though. check it out

 

[Suspect]

whats the timing set at? check and make sure its not too low. @ what rpm is it at idle? not sure exactly what rpm but it should sit some where between 500-1000. im sure others chan jump in here and give more help.

 

[rx750]

When it does idle ok, it's right around 1000 rpm, but it usually jumps from 500 to 1500 when it lopes. The timing is set at 14 btdc. The MAF sensor looked ok, but is there something I should be looking for? I was also thinking that I might not have enough fuel pressure.

Any thoughts?

 

[meangreen92]

When it does idle ok, it's right around 1000 rpm, but it usually jumps from 500 to 1500 when it lopes. The timing is set at 14 btdc. The MAF sensor looked ok, but is there something I should be looking for? I was also thinking that I might not have enough fuel pressure.

Any thoughts?

It may be a charging issue, but it also could be an IAC issue. Possibly a combination. Are you able to pull codes?

 

[rx750]

Yes, I can pull codes. The only thing that came up was something to do with the air pump (because we eliminated it). The charging system seems to be ok, I've had this car as my daily driver for 6 months and haven't had a problem (except for the lope). The IAC is brand new, could it still be a problem though?

 

[green91]

your problem is probably an air problem at idle. there is a spacer that you can install inbetween the IAC and the throttle body that can fix your problem. i had the same problem untill i got the spacer. i dont know where to get one cuz a guy at my work had one. but it has set screws in it that you can adjust and it basically will adjust the amount of air that the IAC will let in at idle. or i believe you might be able to drill a small hole in your thottle plate to allow more air in but i dont remember what size drill bit you need...

 

[STONECOLD]

If the idle is set to 500 then its too low. I have the same cam and anything less than 800-1000 idle and the car is fairly unhappy. Its also more problematic if its on a auto car.

 

[meangreen92]

How about the fuel pressure.
Also, how does it run when you unplug the IAC?
You can also try disconnecting the battery for 30 minutes or so, and see if that clears it up some - in case you've been tweaking on the idle screw.
The throttle plate may be too open, or too closed.

 

[rx750]

It doesn't run at all if i unplug the IAC. I've already tried unplugging the battery. I'll look into the spacer plate and the fuel pressure. Any other thoughts?

 

[meangreen92]

It doesn't run at all if i unplug the IAC. I've already tried unplugging the battery. I'll look into the spacer plate and the fuel pressure. Any other thoughts?

Try adjusting your idle screw to open up the throttle some more. I think it should idle lower, but steadily, without the IAC. Mine does, but then I don't have a big cam, also...

 

[green91]

you should try to avoid adjusting the idle stop screw unless you cant get the idle adjustment plate (which i believe they at brothersperformance.com) and btw meangreen92, if you unplug your IAC and the motor doesnt sputtur and die then your IAC is clogged up and is sticking. but try that website because i believe they sell it there and that will fix your problem because if it runs like that with low fuel pressure at idle then you wouldnt have any power if you drove it. the 5.0's and eec-4 is so touchy to things other than stock. i put only an intake on mine and i couldnt get it to run right and it ran just like what you are talking about and as soon as i put the plate on it went away and havent had the problem since.

 

[meangreen92]

and btw meangreen92, if you unplug your IAC and the motor doesnt sputtur and die then your IAC is clogged up and is sticking.

Thanks for the info, I will check it out tomorrow.

 

[rx750]

Ok, I'll try installing the spacer plate and let you know on the results. thanks