I just bought a 93 coupe w/ 114k miles. It seemed to run fine when i got it, but after a week i started having problems. First I had a coolant hose bust and spray everything down....totally soaked the opti. Replaced the hose and had a little trouble getting it to start until everything dried out....then it ran fine, but hot.....so i replaced the thermostat, and cleaned a bunch of trash out from in front of the radiator...which fixed the problem for a couple of days. I also had the security light flashing every once in a while while driving, and at the same time "sys" would flash on the dash. And the dash seemed to "freeze up" from time to time....the coolant temp or voltage...and gas mileage readings would stop changing....gas mileage would get stuck on 99 and the coolant sould stick and the last reading....and "sys" would start flashing again, then everything would start working again. I tried pulling the codes by grounding the a and b pins but got 12,12,12,12,12,12 everytime. I replaced the battery with a new red top and reset comp in the process....still no codes after another ride. Then on my way home the other night i took the highway and if i cruised at low rpm's in 6th gear it would start to build heat...up to about 245 then cool down to 230....where as driving around normally it was running 230's then cooling down to 215ish. Got home and parked the car....next day it wouldn't crank and stay running. Low coolant light was on so i added a good bit...way too much for just having filled it a couple days before....and i swear i could smell gas fumes while filling it up. There is a residue floating on top of the coolant and i think its gas. I can keep the car running if i pump the gas, and while doing that it revves smoothly....and no smoke at all, but if i don't pump or let off it just dies.
I'm kinda confused...where should i start?.....sorry so long

Thanks for any help

 

If you're getting fuel into the coolant it's either a leak in the intake base or the head.

First off have the rediator pressure checked; it that shows excessive pressure run a compression check on the cylinders.

Since it's now hard to keep running maybe the compression check should come first on the list.

 

I'll do a compression check after work tomorrow. Are we talking warped heads or gasket problems....or more like cracked heads or intake manifold? When we were filling up the coolant it looked like it was be churned up an awful lot...but i thought it might just be the reverse flow.

 

Sounds like you have several problems. Gas in coolant is more than likely a gasket - there's a thread on that somewhere in here. The dash problems are more than likely a bad ground or dirty connectors in the back of the dash unit. Pull it out and clean all the connectors and reassemble.
Welcome and good luck with your project.

 

Take a look at the plugs when you open things up. It should be obvious which cyl has the problem.
I'd suggest that you have a bad head gasket. This may be what popped your hose. This would explain why your coolant temps are wondering around.
I'm not sure how you would get significant amounts of gas in your coolant unless you have a wide open inj. (I doubt it) Fuel press ~45psi Coolant press ~18psi The fuel supply doesn't touch the coolant at all,..... It would take a lot of fuel vapor to go from the cyl to coolant,... and be able to smell a bunch of it. ????

 

This may sound stupid and is probably not relevant, but the description above caught my eye. I had an experience similar to this. I got in the car one morning and tried to start it. It would crank and die. I could keep it running if I pumped on the gas pedal, but as soon as I would take my foot off the gas, the engine would die. Ran fine the night before.

I was trying to figure out how to keep it running long enough to get it to the shop, when I noticed the driver's side floor mat was pushed forward. I pulled it back into place and noticed that it had been bunched up under the pedals. Started the car again with the mat in its proper place and everything was ok.

 

The Sys and Security light flashing indicates a problem in the CCM. The ECM will not set a code so you will see the 12s. The CCM will set the code. The dash is also controlled by the CCM. Check the battery first and if good, then you will need to pull the CCM codes by jumpering A and G. There is a web site out there that has the full procedure, but I do not remember the URL. The service manual details the procedure as well.

 

ok check this out, i went to see if i could keep the car running long enough to pull it like 20ft into the garage....and it runs smooth and doesn't die? it is blowing white smoke from the passenger side pipe now, none on the other side really.....i'm about to do a compression check and pull those codes. wouldn't it run rough if it was a head gasket?

 

any body have a list of what the codes are for the ccm? i jumped a to g, but can't find what they mean anywhere