Bigger injectors, hot start issues....

CManT1914

New Member
Feb 5, 2004
3,172
2
0
Killeen, Texas
Guys with bigger injectors, I have hot start issues. But I don't know if it's from the injectors or the starter. When the engine is hot, it will crank real fast for the first 2 or 3 seconds, then it will die down and crank REAL slow, for about 3 more seconds and then fire up fine. Is that because of the injectors? I thought that all they did was inject too much fuel. That wouldn't effect the speed of cranking would it? I've never messed with tuning it out yet, but it's really getting on my nerves, so I need to fix it. Any ideas?
 
CHris, I dont know. But if you floor the pedal while (and only while) cranking, it cuts the injectors THis could help in figuring out if it is cranking-fuel related.

Good luck man.
 
No matter if they were + or - at start up, they would have nothing to do with the fact that you say it slows down with the cranking speed before starting.

Sounds like a weak battery or the starter is heating up too much.

Grady
 
final5-0 said:
No matter if they were + or - at start up, they would have nothing to do with the fact that you say it slows down with the cranking speed before starting.

Sounds like a weak battery or the starter is heating up too much.

Grady

A-HA!! My battery was just charged, so I know it's not that. I posted a thread a while back about the starter getting heat soaked with shorty headers. Nobody really knew if it was possible. Although Brad mentioned his started doing that after he put his shorty's on. Okay, next thing, anyway of protecting the starter from getting so hot?
 
CManT1914 said:
A-HA!! My battery was just charged, so I know it's not that. I posted a thread a while back about the starter getting heat soaked with shorty headers. Nobody really knew if it was possible. Although Brad mentioned his started doing that after he put his shorty's on. Okay, next thing, anyway of protecting the starter from getting so hot?

I don't buy the heat soak starter thing ...... at least not on the SN stangs.

We had those probs when we were kids but that was starters that were not as good and there was no such thing as shorty headers in those days.

Many peeps like me run lt's which put more heat on the starter than shortys and for all the years I've been lookin on these forums, I don't recall this prob coming up.

It is possible I guess but I really don't think that is whats goin on here.

Do like JT said to shut off the flow when cranking and see what happens.

Grady
 
Going with Grady's wise thoughts:
If it were the starter or you want to play, I would not use wrap on the headers. Instead, fab up a shield for the starter. Foxes do get heat soak, but I agree with Gradymeister that I kinda doubt that it is the starter itself, vs the cables, etc.

If going that direction, I would see if the battery cables get hot while cranking, or even toss a jumper on to see if it helps (I realize this is a real PITA).

Between some of this stuff, it has got to narrow it down. We gotta remember too that if a battery gets discharged, it does lose some load endurance (man, that just sounds wrong). It will have decent volts but not the deep cycle amps behind it.

Good luck Chris!
 
Well my negative battery cable used to get hot, and for a while it would start smoking when it had a hard time starting. It was loosely connected though, and once I tightened it, it stopped doing it. I don't know if it still gets hot, what would this be a symptom of? More loose wiring?
 
I forgot to tell you Chris

I pulled some fuel out of one of those tables but don't remember which one.

IIRC, I did some kind of math deal on the old calculator like 19 divided by 30 or something like that ......... heck its been three years now. ECT and time in seconds were somehow involved.

If you need more info, I can fire up the lap top and poke around for the specifics.

Grady
 
final5-0 said:
I forgot to tell you Chris

I pulled some fuel out of one of those tables but don't remember which one.

IIRC, I did some kind of math deal on the old calculator like 19 divided by 30 or something like that ......... heck its been three years now. ECT and time in seconds were somehow involved.

If you need more info, I can fire up the lap top and poke around for the specifics.

Grady

Yea if you could get back with me on those figures, that'd be awesome Grady!

final5-0 said:
Loose Nut Behind the Wheel :rlaugh: :rlaugh: :rlaugh: :rlaugh: :rlaugh:

Grady

:rlaugh: :lol: That's usually the first thing to check!
 
CManT1914 said:
Well my negative battery cable used to get hot, and for a while it would start smoking when it had a hard time starting. It was loosely connected though, and once I tightened it, it stopped doing it. I don't know if it still gets hot, what would this be a symptom of? More loose wiring?
Can simply be a bad cable. The resistance in cables goes up with heat. So when you mentioned hot-start issues, that was one thing that came to mind. Adding an additional ground is a great idea. I need to do it to the 94 myself. You cant have too much grounding, and it is nice if one of the others starts going south (we only have one decent one).

If it is really consistant in the hot-start crappola, get it hot at home and in a situation where you normally would have starting issues. Put a jumper cable from the battery neg cable to motor (be all careful about sparks and all that stuff that is in the beginning of your manual ;) ). If it starts like a champ, that suggests you have an insufficient ground.

You can do the same thing to parallel any power cable (works for positive too). I do that to find resistive or insufficient pathways.

Good luck Chris.
 
I added 30lb injectors and have the same problems as you, as others have had with to big of injectors. I had the same headers/starter/battery during the time of the swap.

To much cranking fuel when hot cause my slow starts.

Putting the pedal to the floor to crank it helps it out:nice:
 
5spd GT said:
I added 30lb injectors and have the same problems as you, as others have had with to big of injectors. I had the same headers/starter/battery during the time of the swap.

To much cranking fuel when hot cause my slow starts.

Putting the pedal to the floor to crank it helps it out:nice:

I guess I'll never get over the thing about how all our combos are similar but can act so differently. :shock:

It is true, I pulled some fuel out of mine but that was several months after putting the combo together and I never had hot or cold start issues with my 30's.

I only pulled the fuel as I saw several other guys on the Tweecer site who were running 30's say they had the issues. Preventive thinking maybe :shrug:

Don't know if I would go as far to say .....................
30's are too big for a pretty stout combo as I think that kind of talk could confuse peeps.

It is true, 30's could cause some issues on an untuned combo ..........
that don't mean they may not be needed for a safe wot af ratio.

Besides ....................................

If one builds to this level and has no thoughts of tuning the combo ...........

IMHO ...... Their name is Alice & they live in Wonder Land!

Grady
 
i cant for the life of me understand why anybody would put a bigger than stock injector in a car, drive it without a tune, and then complain about driveabiity, idle, and starting problems. another thing, is the battery in the trunk and if so how is the ground? u say the battery was charged, that dont mean jack. was it load tested properly, meaning was it loadtested with half the cold cranking amps. if so, where did the voltage go. if it went below 9.6volts its time to get a new battery.
 
95cobradude said:
i cant for the life of me understand why anybody would put a bigger than stock injector in a car, drive it without a tune, and then complain about driveabiity, idle, and starting problems. another thing, is the battery in the trunk and if so how is the ground? u say the battery was charged, that dont mean jack. was it load tested properly, meaning was it loadtested with half the cold cranking amps. if so, where did the voltage go. if it went below 9.6volts its time to get a new battery.


I agree. A charged battery doesnt equal a strong battery. Try putting it to the floor to see if u gotta mess with the tune, or try swapping batteries with a buddy to see if his battery does the same thing.
 
95cobradude said:
u say the battery was charged, that dont mean jack. was it load tested properly, meaning was it loadtested with half the cold cranking amps. if so, where did the voltage go. if it went below 9.6volts its time to get a new battery.

Kind of my thinking as well. :nice:

Not much reserve left in the battery. :shrug:

Grady
 
95cobradude said:
i cant for the life of me understand why anybody would put a bigger than stock injector in a car, drive it without a tune, and then complain about driveabiity, idle, and starting problems.

How about not being so hasty to say I'm complaining about stuff. I am not complaining about the problem, I'm just trying to fix it, okay?

95cobradude said:
another thing, is the battery in the trunk and if so how is the ground? u say the battery was charged, that dont mean jack. was it load tested properly, meaning was it loadtested with half the cold cranking amps. if so, where did the voltage go. if it went below 9.6volts its time to get a new battery.

Nope, battery is in the normal spot.

Next time it's warmed up and I try to start it, I'll keep the pedal down to see if it's injector related or something else. Thanks for the tips guys. :nice: