wabbitslayer

okay, so I have an 87 5.0 TPI 5 speed and its being a pain to start. it takes like 8-12 secounds for it to start and then it will starts and it runs fine. it seems to just be a starting problem. what i have recently replaced in the past month or two... EGR, o2 sensor, fixed exhaust leak, MAF, spark plugs, disributor, plug wires, coil, starter solenoid, fuel pump, fuel filter. my car keeps pulling a cod 44 (oxygen sensor lean) I don't know what that means exactly. any ideas would help me out.

84redta

iTrader: (34)

not positive on the o2 sensor but when you turn the key do you hear the fuel pump prime for 2 seconds and then click off?

wabbitslayer

I do not hear the pump prime for 2 secounds. I know the pump is good because i just put it in and it's working when the car is on. however i do here it prime 2 seconds after turning the car off.

camaronewbie

You need to look at the fuel pump relay.

There are 2 fuel pump circuits, the ECM/relay circuit and the oil pressure sending unit circuit. The car runs off the ECM/relay circuit. BUT - if that fails for whatever reason, the OPSU circuit will limp the car home. The reason it takes so long to start is that the OPSU has to 'see' oil pressure, then it turns on the pump, then the injectors get gas to fire - this takes a few seconds. This is why the fuel pump was designed to be 'primed' by the ECM/relay circuit before you even try to start the car - since injectors don't hold fuel like a carb.

So, since ECM's rarely 'go bad', you need to look at the fuel pump relay as the issue. Might need replaced, might be a bad connector, might have a bad wire to/from it.

84redta

iTrader: (34)

The fuel pump should be turned on for two second through the fuel pump relay by the ECM. right now it is being turned on by your oil pressure sending unit, because after 10-15psi of oil pressure, it also sends 12v to the fuel pump. You need to try a different relay to see if it could possibly be the relay, I can't remember if the fan relays are the same or not, but you might be able to try them. As I said, you should be able to turn the key to the on position and hear it hum for two seconds and then click off. The clicking is the relay. If that doesn't work, and you've checked all the fuses under the dash and the one near the battery in the engine bay, we'll have to trouble shoot farther into a possible malfunctioning ECM.

I needed an ECM on my firebird two years ago, I was pulling my hair out trying to figure it out.

torque_is_good

turn your key to "on" for the count of 5 before trying to crank the engine. Does it reduce the amount of time needed to start?

wabbitslayer

ok so I checked the fuses and there all good. im not to sure on the relay though... I used a relay from my friends 88 5.7 TPI and it didnt do anything diffrent, im not sure what relay I grabbed from his I just knew it fit in all of my relays that I had. do they make one relay designed just for the FP?

84redta

iTrader: (34)

no, i was pretty sure it was the same as the fans, but it's been a long time since i've tinkered with it. My next suggestion is testing the terminals to the relay. You should have a ground, a power, a signal wire that if you energize will power your fuel pump, and a signal wire from your ECM. The 5th red i believe wire is useless and runs to the ALDL if i remember correctly. I can't find the schematic right now...so running off of memory, orange should have 12V, black should be a good ground, if you run a jumper wire from the orange to the tan/white stripe wire, you should hear your fuel pump running and hear it surge thru your fuel rails, and if you have a volt meter on the green/white stripe wire, you should be able to turn your key and see 12v as the ECM gives that. And like i said before, ignore the red wire. Come back and let us know how it looks.

wabbitslayer

autozone finaily got the relay in today and I put it in and I can hear the pump kick on for 2 secounds now, but it's still being a bit difficalt to start some times like in the cold it was really hard to start... if i let it prime it's even some times hard for it to start, but it is better then before.

MC305SS

This is a good idea also and could be a secondary problem besides the fuel pump relay. Why do I say this, your getting a lean code which might be a fuel pressure problem, a leak down of sorts.
Pump needs to make noise once the key hits the on position, then it must maintain the proper fuel pressure in order to supply enough fuel. If you turn the key on prior to starting and this shortens the start time, then the pump and relay is in order and your having a leak down pressure issue.
Not saying other things can't come into play, but this is a quick simple test to then have you look elsewhere.

84redta

iTrader: (34)

Replacing the O2 sensor could help the fuel mixture if it's stuck in a lean or rich situation. Checking fuel pressure wouldn't be a bad thing as well.

wabbitslayer

OK update, I now just put in a new fuel pressure regulator and diaphragm. It helped a little bit but shes still acting up. My ride is for some reason still wanting to flood its self, making it take a while to start some times mostly when the engine is cold. when the weather is cold its almost impossible to start. the rails will get pressure from the prime right after turning the key then it will just dump all the gas in the engine right after the prime stops. when the car is warm she normally will start right up after about 3-4 secounds. I have just replaced the fuel pump, fp relay, fuel filter, the only thing I can think of it being is leaking injectors. can leaky injectors cause it to just flood instantly when it's cold? need more suggestions.

wabbitslayer

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