I have a 1990 Camry, 4 cyld. 2.0 engine and it seems to be having a cold start problem. What started as a starting issue in the morning has slowly turned into a starting issue EVERY time I start the car. I put the key in, I turn it, it starts....then dies. Sometimes if I do these again, it will start up fine and normally drives fine (meaning if it's not raining and not below 65 degrees outside she won't stall before reaching normal temp). I took the car in, ECU thre out codes for the Mass Air Flow Sensor and Throttle Position Sensor. Had those replaced, the drivablity issues stopped but the start issue remained. WE then replaced the Engine Coolant Tempature Sensor and the Main Relay, and I still ahve the problem. And it is worse when the weather is cool and wet. The IAC checked out, the Fuel Presssure was where it needed to be and the cold start injector seemed to be working properly as well. I had been having issues with the darn thing not staying on for longer than 5 mins which is what propmpted me to take her in. I have no problems going normal crusing speeds...we are stumped. I have, in the last year, replaced the Fuel Filter, TPS, ECT Sensor, MAF Sensor, Main Relay, Timing Chain (replaced long before this issue started), and Water Pump (replaced long before this issue started). My guy thinks it could be the check valve in the fuel pump has gone bad, or that the ECU and the Main Relay aren't talking therefore I'm looking at getting a new ECU.

Any suggestions?

 

Just to clarify:Once Car starts and gets to operating temp. it runs fine and does not stall?
How do you know the cold start injector is working OK?
From description of wet/cold problem worse, I assume your ignition wires, plugs,cap,rotor are OK?
Have you checked for vacuum leak? EGR?

 

When the outside temp is above 70, once car is started she will stay on and not stall or die.
My mechanic said it was. tested it numorus times.
Ignition wires, plugs, cap, rotor are good as far as we can tell.
He checked twice for a vaccum leak. We were convinced it was tempature realted, hence why the the Main Relay and the ECT sensor were changed.

There has also been quite a bit of black smoke coming from they exhaust upon start ups.

 

I'm wondering if it's flooding? Does it seem harder to start the longer it sits? If you have a leaking injector or two or three then it will drip into the combustion chamber and you will have an over rich mixture on start-up. Have you pulled the plugs to see if the color is even for all? Have you tried holding the gas pedal to the floor on start-up to see if that helps? Maybe another test would be to disconnect the cold start injector wire harness and see if it starts any easier, assuming the ECU would then enable the other injectors. If the cold start is working but the main injectors leaking thenremoval of the cold start might balance thestarting mixture. How many miles on this engine?

 

It could be flooding now that you mention it. I called my guy and he is going to re test everything. When he pulled the injector the last time, things looked ok. That's what prompted him to put the pump in Diagnostic mode and the damn thing started up just fine. And he said the other injectors looked good, clean in fact. Yes the longer it sits the harder it is to start. And sometimes when I press the gas and start her up she will start up fine...but not all the time. I know basics about cars and I know that the Cold Start Injector is like the Automatic Choke for my engine and it's almost like the choke isn't working, which would lead one to believe it's either the pump itself not keeping fuel pressure or the cold start injector. I called my guy and he said when it tested it, it was entergized and appeared to be working fine, but that was also at a time when I wasn't having the issue at every start up. Miles on the engine as of this morning are 113,750.

 

Well actually it's as if the choke is working overtime if it's flooding. On older cars you had to play with the choke to compensate for temperature as there was no temp sensor. Frequently cars would flood and not start because the driver over used the choke, usually in warm weather.

Your description of symtoms is a little confusing. If as you say the colder it gets the harder it is to start then a flooding issue would actually improve when colder but get worse when warmer. Hard start when cold can be a malfunctioning cold start circuit since a rich mixture (and a higher idle), as you know, is required for starting. But you say you're getting black smoke and harder starts the longer it sits which points me to flooding and leaking injector(s). The engine coolant tempsensor you replaced was the one on the coolant outletto the rad on the engine,not the one on the bottom of the rad - right? The reason I ask is many people refer to the coolant temp switch as the coolant temp sensor. I prefer fan switch to avoid confusion. As to the functioning of the cold start injector (CSI)did your guy remove it and test it, or is he saying he detects clicking or electricaloperation?

I would still persue flooding at this point. If your guy has a hydrocarbon sniffer maybe you can leave it with him overnight and he can pull the plugs in the morningto see if his sniffer detects very high HC readings that would show a dripping injector. Or he can leave the plugs out overnight, blow compressed air in the cylinders just before start-up, install the plugs and see how it starts. If it starts and runs OK then I would say flooding. You may have to pull the injectors, even the CSI, and send them out to a professional injector cleaning company. They will perform before and after tests and give you an operational curve in the report. I've usedWitchHunter Performance.Your problem will be access to the injectors as you may have to pull the intake manifold.

The other route for flooding is a malfunctioning evap system. If the purge valve is not functioning you could be getting raw fuel through the intake at start-up. Have your guy check that too. He can disconnect theevap. canister tube to the intake manifold and see if that improves your starting.

 

the ECT replaced I believe was the first one you mentioned.

He detected the Clicking and electrical operation. The one thing he is concerned about is a possible failing check valve in the actual fuel pump which isn't allowing the fuel to even get to the cold start injector...does that make sense (I am of course putting it into simple terms).

 

The check valve is there to prevent drain back when the engine is off. If the check is stuck open or leaking then it would take longer to produce pressure on start-up. That would mean less fuel and lean mixture and no black smoke. But it might explain harder starts when cold. But the black smoke is telling you something. Ask him if he has eliminated the evap system?

 

I will. Unfortunatly he just got out of the hospital...minor stuff...but can't get to it until Thursday. so I'm dropping it off tomorrow and hoping for the best.

 

Kind of an update. So I have been mistaken...it's white smoke, not black, coming out of my exhaust....which means A lean mixture right? Also when going up a small hill, the engine reved really low and almost died. And the fuel gauge on the dash ins't making sense. I hit 170 miles on a this tank of gas and the gauge read 1/4 of a tank used...