This is quite the story, so bear with me. I have a ’94 Montego Blue PEP with 89K miles. Last week I ran into the coolant dumping issue through the overflow tank, difficulty starting (warm or cold) and high idle. After spending many hours searching the forum, I found many things to begin checking, from leaking lines to faulty o-rings. I began troubleshooting the easy stuff first and figured out the Pettit AST cap had failed and was the cause of my coolant problem. My car has never run hot or even crept above the mid-gauge point.

Now the issue is starting/idle. It’s difficult to start either cold/hot. It seems like it’s flooded. I found posts addressing flooding and idle adjustment. Here is what I’ve done to date.
- replaced spark plugs (old ones weren’t fouled, but black with carbon and dry)
- adjusted the idle (the adjustment screw on the left side of the TB was already adjusted all of the way out, so I used the adjustment on the right side of TB)
- cleaned air filter (K&N w/ stock airbox)
- checked MAP & other vac lines
- reset ECU (removed neg cable/hold brake 20 sec)
- new gas
- removed new leading plugs and cleaned them tonight (beginning to build carbon)

During starting, it stumbles for about a minute (sounding like a single rotor) with the exhaust popping, then smoothes out and all seems to be well. I’m not getting big puffs of white or black smoke. Sometimes small amounts of white smoke, but I credited that to the rich mixture. Once I get past the starting, there seems to be no performance degradation. No boost or acceleration troubles. I thought I would poll the forum to see if anyone could assist.

My modifications are in the signature.

Thanks in advance for the help.

P.S. - I have completed ALL of the modifications to my car myself using information from this forum. It’s been a great source and I just wanted to say thanks for all of the experience that’s gotten me through my wrench time.

 

bump

 

Just a note - white "smoke" is water-vapor condensation - a small amount is perfectly normal - the combustion process creates water vapor.

The hard starting could be leaky fuel injectors, resulting in a puddle of fuel forming when the engine is turned off, that causes your symptoms. When the engine is turned off, there is still pressure in the fuel lines, so a leaky injector (fairly common occurrence) will result in excess fuel at start-up.

 

Check your idle air control (IAC) and make sure it's functioning and not gummed up
Throttle body service (gummed up?)
Primary fuel injector malfuction/leaking?
Fuel filter/fuel pump/relay problem?
Crank sensor malfunction?
After it's warmed up and you restart, any problems?

 

Thanks for the suggestions. I'll start checking tomorrow (unfortunately, my time in the evenings is limited). Rotorhead, to answer your question, yes it's still difficult to start after it's warmed up.

 

Might just be a failed or failing water thermosensor. https://www.rx7club.com/3rd-generation-specific-1993-2002-16/water-thermosensor-install-398679/

 

Also.. check the pressure regulator (PRC) solenoid & fuel pressure.

 

hey...i have a problem to with my start up it spits out white smoke and i can see water droplets at end of my exhaust, could this mean the coolent seal gone bad. I could decribe the smell as to be.. rich with fuel and not so sweet. The smokes last about 1-2 minutes and fades
thanks,
Andrew

 

Update:
I'm working my way through the list of possibles with no success so far.

- Replaced fuel filter
- checked IAC valve
- checked double throttle control system
- cleaned TB
- adjusted throttle and cruise cables
- checked fuel pump relay
- checked all fuses

still extremely hard to start. Once started it's not smooth (stumbles, backfires and sounds like only one rotor is firing) and now getting lots of white smoke. After a few minutes, everything smooths out, no smoke and the world is good...until I shut it down. I'm dying a slow death here, probably along with my car. Has anyone had these symptoms with their RX?

 

Also after shut-down my tailpipe smokes like the hot barrel of a gun for 4-5 min.

 

Tonight checked out MAP sensor and TPS...both were fine. The hunt continues.

 

I'm having the same problem with mine. Started last night. Although, I DO get a big puff of white smoke when it seems like the second rotor is kicking in. I'm going to do a pressure check on the cooling system tonight to see if an o-ring is starting to fail. I hope it's just an injector that is stuck. Have you ever had your injectors out of the car?

 

Took the car to Pettit today and was told it's probably the coolant o-rings. They are doing a complete check-up/diagnosis. More to come.

 

Hi,

I seem to have the same problem on my FD. Just wanted to know what the final story was on your car ? Please let me know..