92 loyale idle/ missing problem

[tech33]

Hello everyone,

 

I bought a 92 loyale sedan 2wd around 2 weeks ago and shortly after i bought it, have had a consistent issue with it.  Heres what is happening.

 

The cold weather has hit us here in denver and the problem has gotten worse. When i start the car first thing in the morning it idles erratically and stalls out multiple times. Before the cold weather it seemed to start fine in the morning anyway. The frustrating thing is sometimes it starts and idles fine, i drive it around no problem and all is well for the moment. Yesterday i cleaned my IAC valve with seafoam and also poured some into my throttle body. After i did that , i drove it around and thought that i may have possibly fixed this but as soon as i got home i turned the car off and then started it again and it wouldnt idle and would stall out. But when i was driving around it was great. 

 

Here is what i have done to the car since i bought it. I have replaced the battery,plugs,wires,distributor cap and rotor (had to use a different screw for the rotor as i lost the original in the engine bay somewhere, could that have anything to do with it?), also replaced fuel pump/filter/relay, changed oil/filter, replaced coolant/thermostat, added heet and seafoam to my gas, also adjusted my accelerator cable as it was way off before. 

 

I am getting spark/fuel filter flows great, doesnt seem to have any vacuum leaks, the engine turns over fine but wont idle most of the time, if i have my foot on the gas it wont die but it wants to and i notice a very distinct smell like something is burning after i force it to stay running.  EGR problem?

 

Also the car takes a long time to warm up and cools down very quickly according to the gauge. 

 

the only code the engine is throwing is the model of the car, nothing diagnostically , no check engine light at all.  Like i said sometimes i start/drive it and it is fine but its a 50/50 shot, it wont idle as much as it will. any input would be greatly appreciated, 

 

Funny thing is when i first bought the car the idle problem wasnt as bad or i dont remember it being such an issue as i was focused on other issues. 

 

matt

Edited December 5, 2013 by tech33

[maozebong]

replace the idle valve from one in a junkyard, or disassemble and clean.... but im not completely sure that you can disassemble those. 

 

also, verify that the intake boot is not cracked, and the MAF sensor isnt filthy. 

as for the rotor screw issue, have you checked ignition timing with a timing light? this would verify if it is an actual problem.

[maozebong]

kinda sounds like you have a massive vacuum leak if it wont idle, or a defective/dirty MAF sensor. it should have a cold idle between 2000-3000 rpm. 

 

[86 Wonder Wedge]

I would also do a resistance check on the coolant temp sensor to make sure it isn't giving bad info to the ECU.

[tech33]

update:

 

I removed the maf/top square sensor and sprayed a ton of maf cleaner into the cylinder and sprayed off the top piece very well, i also bought another air filter because the old one was very dirty. I also sprayed the maf electrical connection with the cleaner as well. Plugged everything back in and it idles fine, i just drove it about 5 miles and it drove great. Heres the kicker, last night after i cleaned the IAC valve with seafoam i got the same result, took her for a test drive and it drove/idled great until i turned the car off and turned it backed on then it wouldnt idle.     I did the same thing this time , turned it off ,back on twice and its idling fine, only time will tell as the day goes on if it wants to die again. Fingers crossed.

 

Another interesting thing related to the temperature is the gauge is all over the map, it will go all the way up to the 3/4 mark on the temp gauge and then all the way back down to cold so maybe the temperature sensor is the culprit. 

 

matt

[tech33]

another update on this car:

 

still same problem has insanely frustrating intermittent idle problem, start up , dies, start up , dies, starts up runs/drives fine, starts up , dies. Ive put so much time into this car that i can never rely on. bummer

 

matt

[yblocker]

The suggestion by Wonder wedge to check the temp sensor is a good one.  I had similar symptoms as you are describing, and changing it out finally solved it.

The engine temp sensor is the 2 wire unit with the green plug for the ecu. the single spade sensor is for the dash gauge.

Remove it and plug the hole in the head to stop the leak, then clean the sensor up a bit and test it with an ohm meter.  Not sure of the spec, it should have continuity between the terminals.

[robm]

The CTS may be bad.

 

But worse than that, I think you have a bad thermostat, judging by the way the temperature goes up and down.  The CTS is connected to the ECU, and is used only for cold idle control.  The temperature gauge uses a completely different sensor.  If the thermostat is going out, it can be sticky, staying shut until it suddenly opens, causing the temperature to fluctuate as you have described.

 

 

Try a  new T-stat.  While you are in there, measure the resistance of the CTS, and make sure it is properly connected and there is no corrosion in the connector and wiring.

 

Good luck.

[tech33]

thanks for all the input,

 

im gonna check my cts today, also i just bought a thermostat OEM from oriellys auto a couple weeks ago. the car occasionally throws a code for " abnormal injector output" as well but im really hoping its something else causing the abnormal output other than the injector which is a bit pricey.

 

matt

Edited December 7, 2013 by tech33