Out of no where, my car is having trouble starting. It was fine one day, and the next day it wasn't.

Warm or cold, the car sometimes takes at least 10 turns to get it going. It then idles rough for about 30 seconds then acts normal.

After its been running, there are no issues. WOT is fine and AFRs look good at idle and cruise.

The thing that it weird is it happens both warm and cold.

Any ideas? I'm still troubleshooting, but figured I'd post up to see if anyone has some ideas.

Here is a current list of things I am checking:

coolant temp sensor (Check logs to see if it is operating correctly)
cam sensor (Not sure how to actually check. Maybe resistance?)
fuel vapor lock (Tried to keep key on for about 10 secs b4 starting with no help. I don't think stock ECU primes the fuel pump b4 startup)
plugs (Look good)
coils (Car drives OK after startup so most likely OK)
fuel relays
tune (probably not an issue since it started acting up from one day to another, currently speaking with tom about it)

Thanks

 

Could the blend of E85 you are on have possibly changed? I know I have this issue if it dips down cool at night here in the fall and I'm still possibly on a warm weather blend of E85. Same with if I have a winter blend in at the beginning of spring.

 

Yeah I was thinking of that. But that drastic to where it would not start? Doesn't seem that plausible.

I would think WOT AFRs would be way off if that was the case?

It did get tuned in much colder weather though.

 

Mine would start but cut right back off. I'd have to stay on the throttle to keep the revs up until the fuel warms up, then its fine.

I can go that day and swap to the current blend of E85 in the tanks at the station and it can drop as low as 20* outside that night and it fires up the next morning like a champ and runs perfect.

 

Yeah mine will stay running after it startups up. I've been running nothing but e85 for years and throughout the weather changes it was always start regardless of tune edits.

 

Well I had a new IAT sensor laying around and threw that in just to rule it out. I also cleaned my MAP sensor which had some oil residue on it.

After that car started up no problem. Drove around for about 30 mins, got home and shut it off. Turned it back on twice right after and no issue.

Let it sit for an hour and hard start was back? Could the map sensor be going bad? Not sure if this would be a symptom.

Any ideas?

 

So I replaced both cam position sensors and issue seems to still be there. Did a few pulls, car feels fine and afrs look good.

I ordered a fuel press gauge to see if I'm not getting fuel during startup.

I also have a COP on the way so once that's installed I will check for spark during startup as well. New plugs have been installed as well.

Any other ideas?

 

From my OG post:

coolant temp sensor (Check logs to see if it is operating correctly)
Looks OK

cam sensor (Not sure how to actually check. Maybe resistance?)
Both replaced

fuel vapor lock (Tried to keep key on for about 10 secs b4 starting with no help. I don't think stock ECU primes the fuel pump b4 startup)
Low possibility but fuel press gauge on the way.

plugs (Look good)
Replaced

coils (Car drives OK after startup so most likely OK)
COP will be installed tomorrow

fuel relays
Have not replaced

tune (probably not an issue since it started acting up from one day to another, currently speaking with tom about it)
In progress

MAP sensor:
Have not replaced/tested.

 

Having the same issue, also have a slight miss at part throttle cruising that has started since the hard start issue began. Hoping to find a solution!

 

Ordered a new map sensor.

If that doesn't work i'm burning the car

 

The issue in your first post said randomly hard to start hot or cold... is it only hard hot starts now???

Dunno why I didn't think of this before when I posted...but I had some hot start issues when I first swapped to E85. Got my tuner to check it out for me.

The car would crank and run perfect when cold, then I'd drive for 30 min to 1 hr, and let the car sit for over 45 min....it would spin over forever before it'd crank and run. Then when it would crank, it would be flooded. However, I could crank it up right after shutting the car off and it would fire right up. So sounds kind of like your issue?

I wound up having a leaking injector (FIC 1450s bought used, I'll never do that again.) So I sent them to FIC for a rebuild. Afterwards the issue wasn't as bad. But my tuner was able to fix it. I believe it was something in the hot start table that was flooding the car out, simple 2 min fix for him.

 

Sorry if I stated it somewhat confusing. Its is intermittent both warm and cold. BUT it does seem to start up right after shutting off and it does flood after cranking for a while then runs rough for about 30 secs. However sometimes it can sit for over an hour after driving and fire right up.

I run FIC2150's and bought them new. I guess its a possibility though.

If I have a chance ill send them off to FIC for a clean and flow test.

I am going to retune the car here soon so we'll see what that yields.

Thanks for the input

 

So I am still having this issue. Now that its warmer outside I think it's a little worse.

Car completely cold has starting issues as well as warm. Sometimes it will take longer to crank than others. Have to crank over for about 10 secs then it sounds like its missing for a few seconds then it idles ok.

So summary of things I have replaced/tested:
coolant temp sensor looks ok in evoscan
replaced both cam position sensors
fuel pressure looks ok and bleeds off normally when car is shut off
plugs are new
new COP
new iat sensor
altering tune modulates is slightly but does not resolve issue (Tom currently working on it but no resolution yet)
new map sensor
injectors cleaned and tested from FIC all good
new tank of e85

Other thoughts:
fuel relay
fuel pump (buschur doubler pumper installed)
tps
iacv
crank position sensor
wiring/ground issue
fpr

Any one have any ideas? At a loss here.

Thanks

 

Would a faulty fuel pump run normal at cruise and wot but make for issues when starting?
Thinking the car is getting vapor locked when starting.

 

Altering the tune did not modulate the issue.

Seems to be a fueling issue though.