Hard starting lately

Used to be - in c-c-cold weather my LGT wouldn't start right away. Now, more frequent. I've swapped batteries, cleaned cables, etc, but it's taking 15-20 seconds of cranking - sometimes multiple attempts. Especially after the car sits for a few hours.

 

I'm thinking fuel system? As in, maybe i'm losing pressure somewhere? Fuel Pump going out? Any other ideas?

 

Thanks guys.

 

Mods: VF52, 740cc, AVO TMIC, Walbro 255, pro-tune.

This morning, the car even stalled/died approaching a stop. The tach is behaving sorta like a vacuum leak, or as if the ECU suddenly can't cope w/ the light-weight flywheel. Thoughts?

Have you cleaned the MAF and IAT sensors yet ?

 

My 05 ran much better after I did that.

 

Other then that, can you data log during the start cycle ?

I haven't cleaned those - do my car's symptoms match yours before cleaning? If i can find my taxtrix cable, I'll log the start-up. Thanks MC!

 

edit - interesting: your car's output and my car's output show the importance of 'what dyno did you use'? Nice numbers. have you logged 50-80mph?

How old are your spark plugs ?

 

Mine would buck when driving on a cold morning until the engine warmed up. I can reacll if it started hard, may be a little slower then normal. Now even after sitting for days in the cold, I let the gauges sweep, start it and it fires in about 3 or 4 cranks. Just like my 09 with 37,000 miles does.

 

Mine was on a mustang dyno.

 

I haven't logged, but the butt dyno say's it's fast enough, sometimes to fast in traffic.

 

I can't imagine what these things are like with 100 more whp.

Plugs are about a year old. Mine was a mustang dyno, too...but locally known as 'the heartbreaker'. The store didn't want to pay to fix the calibration; since it worked fine for tuning purposes.

 

My car's hard-dipping idle is probably the biggest/telling symptom - that is, telling to somebody who knows. Heh. I'll figure out how to clean the MAF and IAT; won't hurt. Car has 91k miles now; as far as I know it's never been done.

They are easy to clean. Two screws and they come out from the intake pipe after the sir filter. I used a dry Q-tip to wipe mine. Other say to use a non-chlorinaded spray can from the auto parts store.

 

I had a 2 CELs afterwards, both delt with the the two sensors, I cleared them with my Cobb AP. Can has run great since.

I cleaned the MAF and replaced the air filter (we live on a dirt road); last three starts have been normal; although am still getting a dip sometimes, coming off-throttle, as when inching in bumper-to-bumper traffic etc. Some progress, though, is encouraging.

Well with the dusty conditions its possible the plugs maybe a bit more fouled. It wouldnt hurt to pull the easiest one and inspect. Even a slight gap issue will give you intermittent abnormal conditions.

Yesterday I reset the ECU (Found the tactrix), but the laptop battery was too dead to log anything. Will try again.

 

Side note - since the reset, no hard starting. Hope that fixed it.

When my 05 was on the dyno, my Tuner adjusted the idle up and fixed the idle so it won't drop when I pushed in the clutch and it idles about 850-900 rpm so when I coast the engine has more oil pressure.

 

You can also adjust idle with Cobb AP, I think.

yes you can, i bumped mine up 100 RPM. they idle to low if you don't

Don't have a cobb; but will look at ROMRaider and get it done, unless the problem really has been fixed w/ the reset. Thanks guys.

this happened to my friend with similar mods, turns out his walbro needed 2 orings at the pump outlet, fuel pressure took forever to build and wouldnt start as quick as it should. it was also leaning out in the high rpm's....

Thanks bmx - I'll pull the pump next weekend and see what I see. sometimes, rarely, I do get a little fuel smell. Could be something like that? I really need to find the charger for the laptop and log.

the fuel smell doesnt mean anything atleast to the oring issue. however, a poor seal betwee. the pump assembly and your tank will cause similar issues creating vac AND a smell. when you pull the seat up, you remove the 4 phillipshead screws, and see the pump in a black ring, held on with 8mm nuts which can easily be broken if overtorqued- if broken off you wont get an air tight seal. ask hicksta, lol

I'm having a similar problem. Cranks for awhile, stop cranking, then starts the second time sometimes pressing the gas(cutting fuel). Car dies on occasion and rpms dip when clutch is in after rpms drop. I have 159K on my lgt and stock, thinking my fuel pump is going out. I have new plugs and cleaned my maf recently.