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...hard starts?...

so ive searched a bit, but nothing comes up for what i'm after, or if something close doesn't stay on target to my issues.

So i have had the car less than a week. It has 272 cams, and a SAFC-2 tuner. I have issues, EVERY time i try to start. It takes roughly 8-12 secs per start. Battery volts are reading high and normal, yet A/F ratio is bouncing like mad. It runs in a range of 14.5-15.9 constantly while just daily driving. I've yet to meet with my buddy who is very familiar with these motors and such. The battery is rear mounted now, tho that should be at all a concern.

Where should i start looking as far as fixing the hard start issue? Every other vehicle i own fires up in less tha 2 secs, this very much not so.
Next, will i need to first look at the "base tune" left to me on the car for the A/F spike?
 

toybreaker

iconoclast
Joined
Apr 30, 2006
Messages
3,581
Does it do this on a cold start/hot start or all the time?

Do you have a fuel pressure gauge?

Do you have an aftermarket fuel pressure regualtor?

Many of the aftermarket fpr's will bleed the fuel pressure off at shut down, and it will take a momemnt to build again while the engine is operating on the starter.

As a test, just bump the engine over on the starter (and then return the key to the run position) to get the mpi relay to turn on the pump. It'll automatically turn off in three seconds or so.

Bump it again, let the pump time out.

Now, try and start it.

If it's related to fuel pressure loss at shutdown, it will fire right up.

Good luck, and please update your thread with the fix

thanks!
 

Barnes

Well-known member
Joined
Feb 9, 2003
Messages
6,249
Location
Richland, WA
Anytime I hear a thread like this, my first thought is the coolant temp sensor.
 

toybreaker

iconoclast
Joined
Apr 30, 2006
Messages
3,581
^^^ good point, a logger would tell that tale.
 

Specter

Well-known member
Joined
Apr 20, 2008
Messages
367
Location
Karachi, Pakistan
I have the same problem. So continuing with the topic, could spark plugs also cause this? Though mine does it every time whether hot or cold, and i have my fuel pump connected with the ignition, so it keeps on running until i turn the ignition off.
 

as far as im concerned...pump is working fine and runs with the key hot. ill try your little trick as well as look into the FPR and see if anything there. as for the coolant temp, wouldnt hurt to look there either. ill go over those and post again. Any word on my high A/F ratio?
 

Nabeel

Well-known member
Joined
Jul 14, 2006
Messages
260
Location
K.S.A
Try to start the engine at only little touch on the ignition to let the fuel bump start & fill the lines. Then start the engine normal. If it works then your regulator is not keeping fuel or have little leak in tank bump.
 

did that exactly. I turned it over very short, turned back to on position. Waited 3 secs, then fired it right up after about a .5-1 sec delay. So what does that mean for my FPR?
 

Other than getting the FPR issue taken care of, now that i know thats the complication to work off of, what should i look into as far as gettin my A/F ratio in check? right no it's constantly sitting north of 13.5 daily driving normal and occassional hard throttle.
 

toybreaker

iconoclast
Joined
Apr 30, 2006
Messages
3,581
A fuel pressure gauge mounted on the fpr would make these next steps a breeze, as it would allow you to see what;s what immediately, but you can make do if you don;t have one installed.

A good next test to narrow down this issue is to clamp off the return line to the tank after the fpr with a radiused fuel line pinching clamp to prevent the fpr from bleeding pressure back to the tank (the fuelline pinchy pliers are available at harbour freight, the cheapy plastic ones work just fine.)

(you can also use a pair of needle nose visegrips. (the naked jaws might damage the fuel line so you can avoid damaging the rubber fuel hose by slipping a short length of rubber hose over the jaws of the visegrips before using them to pinch down on the fuel return hose, not very elegant, but it works /ubbthreads/images/graemlins/wink.gif )

For these tests you will require assistance. (it's good to have friends! /ubbthreads/images/graemlins/smile.gif )



Run the engine to build pressure, then right as you shut it down, have your helper pinch off the return line inbetween the fpr and the firewall.

wait a bit,

then have your helper release the clamp and try and start it immediately.

... don;t bump the starter, just try and start it without primimng the system

If the fpr is at fault, the car will light right up.

If nothing changes, it may be some a faulty fuel pump check valve or faulty injectors that are bleeding pressure off while the engine is shutdown

To verify there is not a problem with the check valve back at the pump (it closes and holds system pressure at shutdown and prevents pressure from bleeding back thru the pump when the pumpis not running), use the clamping pliers/visegrips to pinch down the supply side.

With the engine running, prepare to pinch the supply line

Shut the engine down and pinch the hose off quickly.

Wait for a bit

Prepare to start the engine

While your helper releases releases the clampy, crank the engine up.

If it starts immediately, the check valve in the pump may be faulty

If you have an injector or two leaking down, neither of these tests will change anything.

To eliminate that possibility, pinch both the supply and return lines

wait a bit

then release both and crank it up

If this test doesn;t show any improvement, you might have some injectors leaking down.

Usually, if that's the case, it'll light up kind of lopsided/lumpy like and run rough for a few seconds as the wet cylinders burn off the excess fuel.

One last tip;

Many of the chip guys can put a "prime" feature into their chips so all you have to do is turn the key on and it'll run the pump for ~ five seconds, no starter bump required, and that'll go along way towards minimising the affect of an fpr that leaks down. I *believe DSMLink also offers this feature in their selectable options, so that may be an option as well.

As far as the afr's, Hertz is spot on, we need to know your fuel trims in order to advise of you of a course of action.

Good luck, and please keep us updated on your progress!
 

I'm going to print that post out and then get a buddy to help lol. As for the AFR, where would i go about getting the fuel trims? off the SAFC, or out of the PDA sotred in the glovebox?

went out and tried the method of priming the pump with the bump start and restart after 3 secs, fired right up.
 

ma70t

Member
Joined
Oct 7, 2010
Messages
10
Location
springfield va
did u change your fuel filter i had the same problem and change the filter and boom problem gone and also check you fuel pump strainer
 
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