Car:1989 Rx7 s5 with streetported NA engine and TII trans back. And some other simple stuff.
Recently, my car has been flooding frequently. I never shut it off until its warmed up, and I kill the fuel pump a second or two before I shut the car off. Then when I go to start it, it seems like every other time I have to crank it for a while and then a cloud goes out behind me. My cabin faintly smells of gas, and so does my oil most times I check it. I've changed my oil the last couple of times at about 300 miles because of this.

Also, last time I checked, I was averaging about 17 mpg combined city and highway. Not the worst, but not the best. I've talked to some people with streetported fc's and they were getting around the low 20's.

About 6 months ago I did a small tune up on the car; belts, spark plugs, spark plug wires, air filter, fuel filter, and O2 sensor. It all went pretty smoothly except the harness plug for the o2 sensor cracked off and I had to wire in a runner from the wiring harness to the o2 sensor plug. I'm not sure if this would cause this or not.

I'm kind of stumped on this and I'm debating weather to buy a rtek ecu to try and combat this. If any of you have any ideas, feel free to chime in.

 

Could be leaky injectors. Could be the water thermosensor. Could be low compression. There's a check connector plug near the lead coil. You can use it to test the oxygen sensor. Use the advanced search feature to find out how to do this.

 

You can also take the reading from the ECU. After the car has been fully warmed and idling take the voltage reading of the sensor. The output of the sensor ranges from 0 to 1 volt. The higher the reading, the richer the fuel mixture is, thus the lower the reading the leaner the mixture is.

 

Hmmm....o2 culprit ey....i've wonder why??mine doing same also after a new o2...

 

Have you tried running it with out the 02?

Im not saying that its ok to run with out it specially when you like mpgs but if the problem started after new 02 the simply unplug it. See if itll flood..

Also, ive never had an 02 sensor in my t2..say what you want..i know. But that was years ago..car ran for 5+ years like that and i flooded once..maybe twice and it was after i stalled the car..like a noob

 

I'll have to check the O2 and see if it's within spec. It's an ngk sensor, if that makes any difference. I also talked to a mechanic friend of mine and he said it might be the water thermosensor. I'll check both.

 

Wohnson89,any update ?

 

So you have a fuel pump switch right? On my car I just turn the car off normally. When I start the car however and it is already warm I throw the switch to turn the pump off until the car starts then throw the switch back on. I have changed injectors and still have to use the switch. One set of injectors I bought used so maybe that are a leaky? Anyways the switch works and was cheap and easy to do and works great everytime.

 

Well I changed my oil and its running better, but so far I haven't had time to do much of investigation. I think it might be the water thermosensor, but I've heard they are kind of a pain in the butt to get to. Once I get a lull in work/classes I will go and figure this out.

Thanks for all the help so far.