each time i goto start the car it takes about 8 complete revolutions of the engine for it to fire and start. its getting spark, i pulled a plug and checked.

I assume its the injectors. I have perfect fuel pressure too, fuel system primes and holds 38~PSI after the fuel pump shuts off. during cranking it goes to 45PSI...

But the engine just doesnt seem to get any fuel for the first 8 revolutions. could it be the voltage drop from the starter causing the injectors to open slower? It drops from 13.5V to 9V during cranking according to the datalogs. I tried adjusting the port injector opening time to no avail.

 

you have a cold start injector? might want to check it

 

IIRC the fueling crank vs pulse tables don't squirt until the 8th revolution. I'm not sure if that's CSI specific or not though. I know my originally CSI equipped car was like that.

 

No cold start injector, and im not running the factory ECM. But is the factory ECM really like that? no fuel until the 8th crank? thats frickin weird.


Its really a huge problem because it drains my battery down so much the alt has a hard time catching up after it gets running. if i do a few start and stops my battery is practically dead and it puts a huge strain on my alt and usually my alt winds up dead in a few days.

Also its the same when cold or hot; harder to start hot though because the motor turns over slower.

 

weird. FPR in good shape? injectors? new? used? multecs?

 

Actually the injectors are Ford SVO injectors, i got them used from a rustang. maybe they are the problem?

 

Ford
Does the ECM you're using have programming for a CSI?

 

I can't remember exactly, but 8 reference pulses isn't equal to 8 engine revolutions.

I had this problem during the winter last year, and again this year. Solved the first time by adding more fuel earlier (first reference pulse instead of 8th or so), and this year just by adding more fuel. Makes me think it's something with the air density that my MAF isn't accounting for correctly.

 

How many crank pulse widths to a revolution? 2?

 

8 pulses i believe.....


1 pulse per cylinder... x 8 cylinders x 1 revolution = 8 pulses

 

first of all no CSI injector provision, and i plan on a stealthram so its no option anyways.

Second of all Im pretty sure there is only 1 pulse per revolution, since the other half of the motor is on its exhaust stroke.

That means that 8 cranks = 8 pulses. remember this is batch fire, one side fires at a time. but it should still get fuel on the first frickin pulse not 8 later.

And its not always 8 cranks, thats just a general thing. sometimes it takes as many as 12 or 15. something is definetelly up.

 

Four reference pulses per each crank revolution.

 

I had the same issue with the injectors not opening immediately. Found the table called "Crank fuel PW multiplier VS ref pulse".
The multiplier for ref pulses 1-8 were set to zero.
At pulse #9 the value changed to .5 ..
Changed the multiplier for ref pulses 3-8 to .5 and the car starts right up.
Don't ya just love F.I. !?!?

 

I would try borrowing a known good battery from somewhere and see if that helps.

The rule of thumb we use when testing batteries (with a tester) is that for a V8 the battery should maintain more than 9.6 volts for over 15 seconds with a 300 amp load. If you're getting down to 9.0 volts after less than that (8, or even 12-15 rotations should be less than 15 seconds) then your battery is definitely not good enough.

Low battery voltage can cause problems with computer systems... especially since you have an aftermarket system with different injectors; newer cars sometimes specify that it can't even drop below 10 volts, I would suspect that new aftermarket stuff might be more sensitive than older factory electronics.

Also, you said you are killing alternators... Going through several alternators in a row often indicates a bad battery.

 

How did you change the multiplier? Did you use a scanner?

 

I also am running ford injectors, and the problem didn't happen untill I changed them... wierd

 

King............
You should think about buying a
'battery tender'.

 

wow this stuff is old. problem is actually in the ECU, of course, I nailed it down a while back with some re-programming thanks to doug flynn.

anyways, um yeah well the car basically got twin turbo'd then ran itself out of oil and now im at a serious rebuild and thinking of going bigger with the motor in the process...

or selling it. check out whats been done since then at my site.