porshapowe

Every morning my car does the same thing. It takes about 10 seconds of cranking before it starts? After that it is perfect all day long. It runs/drives beautifully except for this problem. Ive heard of a check valve in the fuelpump that could not be holding fuel up to the fuel rail. I also am wondering about a part called a fuel pump resistor? Any idea where this fuelpump resistor is located and if it would cause this?? Thanks

GRAND_LS 4

iTrader: (2)

This cant be good for the starter. Might be signs of the starter giving out.

PureDrifter

iTrader: (10)

its normasl, cold battery means less cca

psilosin

My 1991 also has a peculiar habit in the morning that I would like to figure out...

First attempt it will crank and crank but never start (so I just do it a few seconds). Then try number 2 it will catch but stumble and die after a few seconds. Third try always starts up instantly and runs fine. Rest of the day the car will start no problem. Same EXACT senario every morning since I bought it back in August. I'd like to get that figured out before I put her back on the road after winter goes away.

turbosix

try something for me....

turn the key to the fully on position, wait 5 seconds, turn the key off

do it 5 times, then try to start the car.

i know this takes longer than 10 seconds, but this can determine if one of your injectors may be leaking down overnight, or if your fuel pump is doing the same.

porshapowe

Turbosix Im going to try that in the am to see what happens but I thought the LS400 fuel pump did nothing at all until you actually cranked the engine? I know some pumps turn on with the key and you can hear them for a few seconds but is this the same? Psilosin..my car does the same as yours if I dont choose to turn the starter for 10 seconds(which I dont to avoid burning it out). Here are things Ive tried. I tried a new fuel pump resistor with no change. I tried a new air filter,complete throttle body cleaned,seafoam through gasoine tank,tried a different vsv valve fuel pressure control all these also with no luck. Ive picked up a fuelpressure regulator that Im going to try next but imagine that if I had a problem with this there would be other symptoms with my car. Things Im wondering about 1.fuel pump(doent it have a built in check valve) that could be leaking fuel back to the tank? 2.cold start injector(where is this located?and does it sound like this could be the problem?) This problem is driving me nuts too!! I hope to figure it out soon. Thanks Nel

CrazyHawaiian

Whenever I need to troubleshoot a problem like this I usually divide it up into fuel and spark (air also matters but thats rarely the problem). It seems you've spent alot of effort troubleshooting the fuel aspect, have you looked into the spark aspect?

porshapowe

Tried the turn on key for 5 times trick this morning and it made no difference. Ive tried looking at the spark side of the problem with new plugs,wires,new coils,caps,rotors...with no change either

turbosix

damn...

im not sure but i cant imagine why any car would not prime the fuel rails on key-on....


was worth a shot. good luck man!

maybe invest in a FP gauge and stick it on the fuel rails to see if they're holding pressure... cheap guage.. like.. $40 maybe

porshapowe

Ive got a fuel pressure gauge around here somewhere but dont know how to adapt it to this fuel rail...Ill have to look at it. Anyways bought a bunch more stuff(got another fuelpump assembly,IAC valve,tps sensor and another little plastic check valve that sits up high in the gas tank that I dont have a clue what it does) from another good running car that was hit. Tried the tps and no change. Tried the IAC and no change. I thought it would be the IAC as my idle is at 400rpms in park on a warm engine. Next Im thinking changing out the fuelpump...who knows... If anything I will have alot of parts available if anyone else will need them. Thanks again everyone for the help!!