I set the fans to turn on earlier...when the temp reaches where it is supposed to turn the second fan on the car goes nuts. The idle starts bouncing all around. Anybody know why, and how I can fix this?

 

what did you set it at....???

 

Look at the INJ and do a map trace when your fans are on. Which cells is it bouncing on and to what? Have much of a bounce? Also, what are your idle settings? All of them?

Might as well post your mod list too.

 

Hmm, I'm wondering if the PFC thinks the AC is kicking on when it's not... Try diconecting the AC fuse and AC relay.. also check the switch on/off setting on the PFC when it starts doing the jumpy idol and see if the AC Switch highlights as on...

 

ok I tried to post the short version earlier, but...I noticed this behavior before the PFC. First, I have an automatic-WAIT don't stop reading! Before I would notice that when I stopped anywhere and then restarted the car (hot) the revs would go straight to 3K (NO ITS NOT THE AWS!) then start to bounce between 1.5 and 3K. Really embarrassing. I've been getting around this by immediately putting the car in gear. This has the effect of smoothing out the idle, but at around 1.5K. After I get moving and the temps drop down, the idle goes down to 900 or so and everything is normal. I never knew what it was. The only time it did that was during a restart when the temp was >105 (heat soak). OK so yesterday I'm driving around with my laptop. It's so hot that the lcd screen goes black, so I gave up, but I pulled into the carport and noticed that the temp was 98. So I'm gonna reset those badboys (fans) right?! I don't remember the original settings, but I changed the fans to fan1a/c 88 fan1noa/c 90 fan2 95 an update. BAM, immediately the revs go to 3K and then bounce bounce bounce between 1.5-3k. Scared the sh*t out of me, so I shut the car off and let it sit. Restarted and put it in gear. High idle, temp 98. Drove around the block temps hit 94, boom idle goes down and no more bouncing. Temp continues down to about 89 and stays. I pop the hood-both fans appear to be on. My idle settings are 900 and 1300 with load. Sorry for the long post. Any ideas?

 

First verify that the TPS voltages are correct, ETC_sensor screen.

Make sure that the throttle closes all the way and does not hang up sometimes.

Adjust the throttle set screw and air bleed screw (close them) to reduce intake air at idle.

After getting all about normal, reset the ecu and let it learn again from scratch.

 

Thanks for all the replies. I really appreciate it. I'm about to take the car off to have the motor freshened and a single turbo, etc. put on, so I'll have to investigate later. I was thinking it may be something to do with the clutch switch, etc, since I have an auto. Chuck, I really appreciate your response. The throttle never hangs. The idle is perfect unless the second fan kicks on. Hopefully the radiator and other stuff I am doing will help keep it from getting too hot.

 

I have a 1994 auto also and my car behaves just as badly. The idle jumps all the time only if my AC is on Level 1 or 2. Also, I have an upgraded radiator and ducting and my car overheats the minute I come to a stop or drive slow. Temps routinely hit 100 C if I'm slowed down for more than 15 minutes.

With the idle, I notice that if I put the car in Neutral that temps go down and the bouncing more or less stops. However, I cannot figure out what the deal is.

My motor is find. My radiator is fine. Both fans work per visual inspection. I cannot figure out the idle or the temp issues. I am getting dual Mocal oil coolers, wrapping my downpipe and installing Perma cool fans because I have no other ideas.

 

I am also going to updrade the oil cooler and the trans cooler. I am also going to try some redline water wetter and also changing the coolant mix to favor water, maybe 60/40. what mods do you have?

 

I have NEVER believed that the stock water pump was adequate, and in addition, it has been proven that it cavitates at high rpm (hence the pulley kits, and the now no longer available race water pump. I have talked with Charlie at Mazcare about this and since my car is so "new" (I do land speed racing with a FD), with a newly built motor and T-88 turbo and my own air-to-refrigerant (liquid) intercooler, WE HAVE NO IDEA what will happen if I keep the water pump the same. I suspect, however, that I think that an electric water pump, tied to a turbo timer, along with an accusump for the turbo makes sense to me. Any thoughts there?

 

Meizer (sp) sells a electric h2o pump and adapter piece for the `13B... Summit racing sells them if you need one...

 

I didn't find one that Summit sells with the plate for the 3rd gen. I have the plate and the older version of the pump.