Ok i replaced the coolant temp sensor and the coolant temp switch because the car was hard to start when it was hot. But now it doesnt want to start at all! I just went out right now to go somewhere after the car had sat for maybe 2 hours and it took forever for it to start! I thought it wasnt going to start then it fired up ran like **** for about 5 sec and then ran perfect?

Car has good plug's a new fuel filter,pcv valve,waterpump,radiator and such..

Please any pointer's would be much appreciated!

 

Ok after some searching im going to get a fuel pressure guage tomarrow and hook it up and see what it's telling me.

 

Exactly what did you change out? There's the temp sensor in the driver's side head (no affect on starting), and the temp sensor in the water pump housing (PCM uses that to determine cold start A/F ratio). There is no temp switch. Did you get the correct sensors -they are not the same - single wire in the head, two-wire in the water pump?

 

Ohh thank you for helping me out...I replaced the sensor in the head it is grey with two pin's but one pin is verticle and connect's to nothing. I also replaced the sensor at the bottom of the water pump it has a black plastic end with two round pin's.

See when i first got the car it ran great except when it was hot sometimes it would take about 5sec of cranking to start. Well after a week or so it steadly got worse! Up until yesterday when i checked the fuel filter and spark plugs and there wires i decided to change those sensor's.

Now it's as if the car is imposible to start taking like 2min of continuious cranking then it will suddenly just fire run real erradic and choppy for about 5-10sec then run ok. Only other thing i can tell after it clears up is the idle fluctuates and i can hear it lumping at idle like it is missing or something but it is very slight and hard to notice.

This is my daily!!!

 

After reading for a couple hours last night on this problem i decided that i would try to start the car a different way this morning. Usually its almost impossible to start in the mornings...So this morning instead of turning the key to the on position and try to start the car i turned it to the on position until i heard the fuel pump stop priming then turned it off and back to the on position very quickly! After doing this three times in a row i tried starting the car and walla it fired up and then died..lol But it started the next try like normal?

So basically its a fuel problem right?

And it is going to be ethier the fuel injectors,the fuel pressure regulator or the fuel pump itself correct?


OK UPDATE......I pulled the vac hose off the FPR and stuck it im my nose and sniffed and i deffinatly smelled fuel is that a clear sign the FPR is bad?

Ohh and one more thing my fuel mileage is horrible right now too..Its worse than my old 73 GMC with a 350/350 4 barrel carb!!

 

i am having the exact problems. does yours shake when you finally get it started and then all of a sudden it feels like it just clears out and runs smooth again?

 

Start by checking the fuel pressure. If it primes to ~40psi, then drops off rapidly, its the check valve in the fuel pump, a leaking fuel pressure regulator or leaking injectors. Next time you try to start it, put the accel pedal to the floor before turning the key to "start". That puts the PCM in "clear flood" mode. If it starts quicker that way, may be leaky injectors flooding it.

A leaking FPR will usually put wet fuel in the vacuum line, not just the odor, but its still a possible problem.

 

Yes!

I just got done replacing the FPR with a new unit. I know i should have trouble shooted it more but i run a business and every hour my car is down costs me money!...It's pretty warm outside right now but the car starts normal as far as i can tell i will drive it alittle and see if my fuel economy gets better and see if the hard start problem persists...

Im going to pull the fuel rail's and turn the key to on to see if my injectors are leaking...But i have an apointment to go to right now!

 

did this fix your problem?