paw140

I'm in the process of troubleshooting hard cold starting. My car has done this off and on over the year that I have owned it. Sometimes it will start right up, and other times I have to crank on it for a little bit and give it gas.



Anyway, another weird thing that my car does, is that no matter what temperature the engine is at, the fans will turn on about a minute after starting the engine. They will stay on for about 10 minutes after shutting the car down. It does this EVERY time; it doesn't matter how hot or cold the engine is. I think one time I actually just turned the ignition key to the 'on' position, and without starting the engine, the fans came on after about a minute.



I'm just wondering if the two problems could be related. What sensor tells the fans when to come on? Is it the coolant temp sensor? The same one that tells the ECU the coolant temp? Where is it located? (the one behind the water pump housing?)



Thanks,



Paul

'94 White PEP

Fd3BOOST

Your starter could be going out. But if it is getting fuel and spark it should fire right up. Sounds like you have some gremlins to chase.



The fans,, hmm I really don't know. I have never payed attention to them other than to see that they work.



You can get a workshop manual at this site for download..ILuvMyRx7.com

paw140

It's not the starter, unless it's worn out and just not turning over the engine fast enough. I'm definitely getting spark and fuel, I'm just thinking not in the right ratio. When it doesn't start, you can hear it fire and I have to give it throttle to get it to stay running. I might also have low compression... 91K miles on the original engine. Although I have yet to see someone say they had starting problems on an FD due to low compression.



I have the shop manual, but its just soooo hard to find anything in it! Its the most disorganized and unspecific shop manual I've ever seen!



Thanks for the suggestion. My thought was that the coolant temp sensor is messed up and telling the ECU that my engine is hot all the time, thus causing my fans to come on and giving me cold starting problems. I'm just wondering if the fans are triggered off of the coolant temp sensor.

paw140

WOW! I just opened up the shop manual, and the page it just happened to open up to was F-219, Service Points. Listed under 'Engine coolant temperature sensor' is this. '* A malfunction in the engine coolant temperature sensor or its circuit will cause hard starting or engine stall when engine is cold. * In the above condition, the electric coolant fan will constantly operate when the ignition switch is ON.'



Sweet... now I'll have to pull it out and check it.

paw140

The shop manual says I have to pull the UIM to remove the sensor. Anyone have any info on this? I haven't looked at my car yet, but from the pic in the shop manual, it looks like I don't need to remove the UIM.

Fd3BOOST

See what happens when you start reading. Just think you could have probabley fixed this with us ever even knowing. .

apexkw

i did it without removing the uim and it was a bitch. i had to get someone with small hands to get the sensor back in. luckily for me i have small hands. anyways you dont have to remove the uim, although i think that it would be much easier to pull the uim now. if you dont want to remove the uim then just pull all of the pipes and stuff above the watertemp housing. you can get it with a opened wrench.

r_xplicit

i know that you can do the water thermosensor with out taking off the uim, but i do not know about the coolant temp sensor.



are you getting a code on the sensor?



the fans sound like the fan mod that is done at the sonnectors under the hood. where you gorund a wire and they stay on almost all of the time. the 10 minutes after shutdown sounds like the mod to me.

r_xplicit

paul, also, i used to notice that my car had a little trouble starting sometimes too. i could only deduce, after doing the block off plate installation, that the acv was worn out, and dirty, and almost non-functional looking. since, i have had no problem.....



just another thought.....

paw140

What is the difference between the water thermosensor and coolant temp sensor? Aren't they the same thing?



I was thinking that a fan mod was keeping my fans on. It's my understanding that the fan mod is done by grounding a wire near the ECU. I checked mine out and it looks stock.



I'm not getting any trouble codes, which kind of bothers me a little, but I'm going to pull the coolant temp sensor when I get a chance and test it. I'll let you all know what I find out.



Thanks,

Paul