hard starting after running/warmed up!

[BoostedSUV]

I've been chasing this issue for a while now and I've finally gotten fed up with up. I did a search and didn't find what I was looking for. So here's the issue: When I start my Ty cold, let the pump prime for a few seconds then turn the key, it fires right up after about half of a crack. Now if I let the truck idle for a few minutes to warm up, or go for a long ride (doesn't matter) and I try starting truck up again a short period thereafter it gives me a hard time starting. It will crank and poof as if to try to start then keep cranking... If I hold the throttle wide open it will crank then eventually start, run rough, rev it a few times and sometimes it will clear out. Sometimes it keeps running like it's flooded with fuel and wants to shut off. It idles and runs fine normally, doesn't appear to be running rich or dumping fuel prior to this happening.

A few times in the past the only way I could get truck to re-fire was to hook it up to jumper cables, or a battery charger. It was as if the extra kick at the battery was enough to fire the ignition system. I changed batteries and tested alt and I can get it start now if I hold WOT when I have this issue but it didn't fix it. Things I've changed: (just in general after/during this issue) Spark plugs, fuel pump, vacuum lines, battery, MSD distributor, 52mm BBK throttle body with different TPS/IAC.. I had problem prior, and still have currently after changing these things.

I have good fuel pressure, holds 40psi when priming the system and letting truck sit, so I don't think an injector is leaking down?? I recently installed a remote start and half the time the truck wont start using it unless it's first thing in the AM or after 8 hours of work.

Sorry for all the info, i'm just trying to elimate obvious questions and offer as much as I can. Thanks! I hope someone can point me in the right direction :tup:

 

[kentuc]

Re: hard starting after running/warmed up!

Temperature sensor at the front of the intake manifold.

 

[The Devils Own Chariot]

Re: hard starting after running/warmed up!

I have the same problem. It happened to me at street drags last year and was not able to race. I got jumped and BAM, it started right up no problem.
My guess is you have a battery relocation? I have my battery in the bed of the truck and run 2 gauge wires to the starter. I think the heat of the engine bay changes the resistance of the battery cables and suddenly we are not able to draw enough current to turn the starter over. My other theory is there is something drawing current that we don’t know about yet. I’m not saying this is the answer but rather my theory. It will be interesting to see what some other people say.

 

[Don W.]

Re: hard starting after running/warmed up!

:2cents: From what you describe my first thought is it's flooded. Next time try holding the pedal full down and see what happens. This puts the ECM in "flood" mode. If it starts somewhat normally AND you can repeat with this method then look for the source of the flooding. If it's holding FP like you say then maybe I'm flooded. :lol: Hot or cold you should be able to hear the pump and see FP come up with key on before you go to start.

Maybe something is over pulsing the inj's when the motor's hot. How's that for an off the wall thought?? If the ECM is not sensing eng temp (bad or disconnected sensor) then the ECM will initiate cold start even when the engine is hot flooding the motor.

Just some random thoughts, someone can blast me out of the water on this.:rotf:

 

[The Devils Own Chariot]

Re: hard starting after running/warmed up!

Temperature sensor at the front of the intake manifold.

How will that affect starting?

 

[BoostedSUV]

Re: hard starting after running/warmed up!

Temperature sensor at the front of the intake manifold.

is that just a guess? haha You are talking about the sensor for the ecu and not the one to gauge correct? I didn't think about that and it's worth a shot. A little more explaination as to why that suggestion would be great :tup:

 

[BoostedSUV]

Re: hard starting after running/warmed up!

How will that effect starting?

I was thinking that as well.... that idea never crossed my mind. :dunno:

 

[The Devils Own Chariot]

Re: hard starting after running/warmed up!

So do you have the battery relocated?

 

[BoostedSUV]

Re: hard starting after running/warmed up!

So do you have the battery relocated?

it's relocated to the driver side to clear the turbo/intercooler. I ran the factory 4 guage cables, they reached over to the other side with some re-routing.

 

[BoostedSUV]

Re: hard starting after running/warmed up!

Don W. it definitely seems like the motor is flooded. It starts fine, warms up fine, shut it off and go to refire in 5 mins it wont start. Have to hold WOT throttle, it starts blows smoke and smells like gas. Hot or cold the FP holds pressure. Right at 40psi with engine off... even a half hour later. Seems like temp sensor is a good place to start

 

[Captain Morgan]

Re: hard starting after running/warmed up!

do you still have 50# injectors?

I had this problem start immediately after I "upgraded" to 50# injectors and custom chip. I never had that issue with my stock injectors and ATR chip, which is why Ill be going back to them.

But I had the same issue, sometimes after a short cruise, if I stopped somewhere Id have to wait almost an hour to get it to start again, then I just started carrying a can a starter fluid to get it fired up off the bat, its the only thing that would work.

 

[kentuc]

Re: hard starting after running/warmed up!

If the sensor was defective (wrong or no signal) the ECU would be allowing a rich or lean amount of fuel. In this case it sounds like the mixture is too rich.
It usually effects cold starting but it`s not too expensive to try.

 

[BoostedSUV]

Re: hard starting after running/warmed up!

do you still have 50# injectors?

I had this problem start immediately after I "upgraded" to 50# injectors and custom chip. I never had that issue with my stock injectors and ATR chip, which is why Ill be going back to them.

But I had the same issue, sometimes after a short cruise, if I stopped somewhere Id have to wait almost an hour to get it to start again, then I just started carrying a can a starter fluid to get it fired up off the bat, its the only thing that would work.

yup, I'm running RPM 50# flow matched injectors and a Nolan tune. I've been running these injectors for over 2 years with an ultimate chip but this problem started about 6 or so months ago. Not sure if it's in the tune Nolan did for me? I can usually get it started eventually but it's just a royal pain and embarrasing when some one is checking out your typhoon and you can't get it started! :tdown:

 

[Captain Morgan]

Re: hard starting after running/warmed up!

yup, I'm running RPM 50# flow matched injectors and a Nolan tune. I've been running these injectors for over 2 years with an ultimate chip but this problem started about 6 or so months ago. Not sure if it's in the tune Nolan did for me? I can usually get it started eventually but it's just a royal pain and embarrasing when some one is checking out your typhoon and you can't get it started! :tdown:

do you still have the ultimate? swap that out and see if that changes anything, that will be your easiest/cheapest way to start diagnosing things.

I have a chip by another well respected tuner on here, I dont think its anything he did either, I think its a combination of things and the injectors, cause I talked to another person a little over a year ago who had the same issues as we do, also with 50#'ers and a custom tune.

 

[BoostedSUV]

Re: hard starting after running/warmed up!

I've noticed since installing the BBK throttle body a few days ago I've even been having a hard time getting truck to start cold. If I don't hold it WOT it will just crank until the battery goes dead.

 

[NecroWolf]

Re: hard starting after running/warmed up!

iac problems?

 

[BoostedSUV]

Re: hard starting after running/warmed up!

If the sensor was defective (wrong or no signal) the ECU would be allowing a rich or lean amount of fuel. In this case it sounds like the mixture is too rich.
It usually effects cold starting but it`s not too expensive to try.

If this were my problem wouldn't I get a false reading for engine temp when connected to datamaster? I've had this problem for a while now and when I had it connected to the laptop the engine temps read accurate.

 

[NecroWolf]

Re: hard starting after running/warmed up!

yeah the temp sensor they are talking about would be the one you see through data master. if it started right after you changed the tb i'd suggest starting in that area

 

[BoostedSUV]

Re: hard starting after running/warmed up!

yeah the temp sensor they are talking about would be the one you see through data master. if it started right after you changed the tb i'd suggest starting in that area

The problem existed with the stock TB as well. Just seemed to get worse with BBK. All the sensors are new and and I set the idle screw to the same spec as my stocker so I'm not sure what else could really change? Its only pulling more air...

 

[NecroWolf]

Re: hard starting after running/warmed up!

what voltage are you seeing with data master at the ecm. might need to put a relay in and a direct feed from the bat to bring it up. when warm cranking you might be getting a resistance increase at the starter from heat causing a higher amperage draw and a low voltage to the ecm which will cause the ecm to command more injector pulse width. it's a really simple thing to do. you just need some ten guage wire and a relay. i believe it's the pink with black stripe wire running to the ecm. you just cut the wire use it to trigger the relay and you're good to go. there's a write up around here somewhere. on my fast xfi system i was seeing a 2-3 volt drop with my battery in back. i had even ran a seperate 4guage wires to feed my starter and accessories. so while my ecm was seeing a voltage drop and telling the inectors to spray more fuel the fuel pump was still seeing full voltage and flooding the engine