Vortec5300

Recently my car has started acting funny on cold or warm starts. When I turn the key, the engine turns over and over before it finally lights off. Once its running it runs fine and if I shut it off and then immediately restart it, it will start right up instantly but if it sits for 5-10 mins and I try to restart, once again in turns over and over before it starts. It only has 33k miles on it, and the fuel pump is a Walbro 255 with only about 5k miles. I just changed the fuel filter and I can hear the pump prime when I turn the key before I try to start it. I also checked the spark plugs just incase they were fowled and they were perfect.

Has anyone ever seen this? It kinda points me towards the fuel pump but I do hear the pump run so... I have always ran good 93 oct. so the tank sock should be clean. NO Check engine lights or anything either. I guess my next thing will be to install a fuel pressure gauge and watch the pressure on cold starts.

I am just curious if any of you guys have ever had this problem???

Thanks for any tips!

Vortec5300

Well after doing a search, its seems this is a common problem for these F-bodies. From what I read, it definetly points to the fuel system but no real answers. Its like when the pump runs to prime, it is not picking up fuel correctly. The system seems to hold pressure because I can kill the engine and start it up within a min or two and it will instantly start. But eventually the pressure apparently bleeds back off and the pump is not priming correctly. Gonna go try to find a fuel pressure gauge now.

Vortec5300

Damn. no one else has seen or solved this issue that seems so common?

redz284u

iTrader: (1)

i have the same problem, i've asked and asked and asked and nothing......done the pump, filter, new maf, ls6 intake, thinking it had something to do with the air/fuel, but nothing seems to make it go away....only thing left is timing and injectors......if i ever get to those ill let u know........

Splitz

iTrader: (1)

Had a similar problem last week, turned out to be bad battery and corroded battery cables and a bad connection.....just a thought, check battery voltage at the battery, then battery terminals.....

Don't slap me if you've already done that........

MJK

iTrader: (3)

My brother's 98' TA does the same thing.We have checked all the usual suspectsand still nothing.We have also checked the terminals,and its had a new battery installed.The car runs great EXCEPT for that starting problem...

Car also has the Walbro pump but was doing the problem since BEFORE the pump was installed.New plugs,wires,cleaned MAF,fuel filter,checked all vacuum hoses that we can find.

Starter?I doubt it though.It doesn't seem to have ANY problem turning over,just won't light until the second try.Also runs a little "chuggy" when it hasn't run in a few days.Clears right u though in a minute or so...I'm thinking that possibly has something to do with it.

Watching this post man,if you find anything out...post up please!

1badragtop

Has anyone hooked up a fuel psi guage? If not try that and see if fuel psi drops over time. If your fuel psi drops more than 5psi you have a leak- either from check valve in pump or leaking injector, external leak, ect. If you don't have a fuel psi guage, try this: after the car sits a while and when it would normally act up, turn the key from off to on like 3-4 times, then try cranking. If the engine fires right up, you most likely have a fuel leak problem.

MJK

iTrader: (3)

Had that same idea as well man.I tried priming it a few times like when you change your fuel filter or relieve pressure in the fuel system for any reason and,nopers.Nothing.Still did the same problem.I should still get a hold of a guage though to confirm wether correct pressure is there.

Any guage recommendations?Any fittings needed as well?

1badragtop

If you can get a set of guages, I definately would verify proper psi. I think any universal fuel psi guage will work, however I don't recall off the top of my head weather it has a port with a shrader valve or if you have to "t" into the line.

Vortec5300

I have also tried hitting the key a few times to prime the pump before I actually turn the starter over. It does seem to help. I couldn't imagine the fuel system would hold pressure overnight or for long periods of time. BUT it does seem that the pump should prime the system faster then it does. I can hear the pump run but it doesn't sound like its loaded. After two or three bumps of the key, I can hear the pump sound different like its got fuel in it, then she lights right off. My car is not a DD and it was fine last time I parked it. Then just a week or two ago when I went to start it, it did this for the first time. In my opinion there will not be pressure in the system if the car has sat for a while but, as soon as you turn the key to start it, that pump should prime up and pressure the system instantly. This thing should not turn over more then 1-2 times before it starts.

I am wondering if its a Walbro pump problem. My car only has 33k miles on it and does not have a lot of extra electrical BS installed. I checked the plugs and they are perfect. I will get a gauge and watch it and see what it does. That thing should hit 43psi as soon as the motor turns over.

Splitz

iTrader: (1)

loosing pressure because of the gas cap???

1badragtop

If memory serves: as the fuel leaves the pump, it pass threw a check valve. So if the there is no leak external or internal, pressure at time engine is shut off should be really close (within 5psi) of when you go to start ot back up. Post some fuel psi readings, as I am curious to see whats going on. The problem sounds either fuel or electrical related, since i doubt air and compression will glitch as to your concerns exist. My money is on a fuel problem, though it could be any number of components causing it. Seems like many people have had bad luck with this problem, so lets try and find the solution so others don't have to live with it. I know if its this common it is bound to happen to me someday. LOL.

csucguy18

iTrader: (5)

Ok, i acually had the same problem with my camaro today, would crank but wouldnt start. I thought it was the fuel pump...did the turn key 3/4 time to build pressure and the car started right up. So that means that i have a fuel leak problem?? im a newb so what does that acually mean, that im losing pressure somewhere in the lines? If so, how do i diagnose this? Also does this mean that the fuel pump is working fine? thanks for any help in advance.

Vortec5300

I haven't got mine fixed yet. I have just been cycling the key on a couple times before I start it and it primes right up. Its definetly got something to do with the check valve, where ever that thing is. My fuel pump is a walbro 255 and its only got 6k miles on it. Check valve has got to be inline somewhere. It is an annoying problem though. I thought for sure someone has seen and fixed this issue but...

Dimitri-

iTrader: (10)

Mine was doin the same..
Dunno if it was the pump, but it wasnt the filter cause I replaced it.
Took it to a mechanic today, said it could be a vacuum leak.

LS1ruben

Mine is doing the same thing now. I replaced the fuel pump relay and fuel filter to no avail.

Dimitri-

iTrader: (10)

Check the MAF sensor, took mine to a mechanic and they said it was that

replaced it for 375 =\

LS1ruben

Did it seem to fix the problem?

Dimitri-

iTrader: (10)

For me?
Yes

hope it stays like that :O