86firebirdta

Hey guys I have been in need of some help for a while now and yet to fix the problem.... I have a 1986 305 tpi, I jus recently put in a sum-1102 cam, double roller timing chain, edlebrock intake, slp runners all ported and siamesed, dui dizzy, underdrive pullies, hooker headers, accel 19lb injectors, 1.6 roller tipped rockers, new computer, pretty much all the lil goodies for it... The way i set my timing was put the #1 cylinder tdc and put in the dizzy at firing point 1, all it does is crank with maybe one backfire. I turned the dizzy 180* to point at firing point 6 when the #1 cylinder was tdc and i started getting about 3 backfires.... I am also gettin fuel coming out of the pcv out of the manifold, pretty lost and lookin to get some help, any advice would be greatly appreciated thanks.

-Tim

fyrebird68

iTrader: (1)

Fuel out the PCV valve certainly sounds like timing. Pistons are pushing fuel in the wrong direction!

I'll ask the obvious questions first. Don't take them personally - some people do get them wrong.

> Are you sure your cam and crank sprockets were aligned correctly when you changed the chain? If you got them aligned, but 180 out, your distributor will be 180 out
> Spark plug wires in the right order? 1-8-4-3-6-5-7-2, spinning CW. Check BOTH ends, at the dist and at the plug.
> Easy way to be sure you have TDC is take the plug out of #1 cyl and put your fnger on the spark plug hole. Crank the motor by hand. The compression stroke will push your finger off the hole. Than crank until the timing mark is on the pointer. Distributor should now be pointing at the #1 spark plug wire.
> Check to be sure you stabbed the distributor in right. You mention "firing point 1" for setting your timing. I assume you mean the dist plug connector for cylinder #1, where the distributor is pointing when it's at TDC (Hey I had to ask...I've seen guys mark the distributor for #1 and not realize that things had changed, and they now had a new #1 plug wire location.)
> Harmonic Balancer OK? The rubber can slip and throw the timing mark way off. To check it find TDC for #1 cyl using the method above. Use a TDC gauge or something soft to check that the cylinder is ALL THE WAY up. Balancer should be on the mark.
> Good fuel pressure? 40psi at the rail?
> Injector stuck open, dumping fuel all the time? This would show up as a rapid leak-down of fuel pressure when the motor is not running.
> You didn't say if the cam was brand new or pretty new. A worn exhaust cam lobe can cause backfires because the exhaust stroke of the piston pushes back toward the TB when the intake valve opens instead of pushing it out the exhaust. Broken pushrod, rocker or collapsed lifter would cause the same thing.

Hope this helps.
Bob T.

86firebirdta

The cam, is brand new got the kit with the lifters... I have 50 psi at the fuel rail with no sudden drop in pressure, I did put my finger over the #1 hole and air was pushing out around my finger it was pointing at about 2-6* btdc and that was where i figured #1 to be with putting in a little feeler and didn feel it come up any longer then set the dizzy where the #1 point use to be. Right no I am in the process of going back the the timing chain and re checking it, I am pretty sure it is set right that a local mechanic and member put on. Its jus goin back to step one and checking again. thanks for the imput.
-Tim

86firebirdta

I got everything put back together a few days ago tried to crank it over and still nothin.... checked the spark and it was really weak with fuel all over the plugs. i changed out the dizzy and put my stock one back in and the spark was way better, but still nothin. i have 2 codes poppin up 34 maf sensor and 42 the est. i have no idea where to start for the est i would appreciate any halp, thanks.

camaro1185

For the 34, I would unplug your maf, and see if your car even starts.

I had the same probplem with mine where my car would set a code 34 and would crank but not start. I pulled the maf connector and it fired up.

Also check those relays on the ds firewall.

For the est, are you sure its hooked up correctly?

Make sure all your fuses are good.

86firebirdta

i never unplugged the est still the original sensor so i jus ordered a new one today be in on the middle of next week.

86firebirdta

okay i finally got some progress today... i flipped my wires 180 around and bam wanted to start really really bad but didn, so sprayed some starter fluid and bam started and idled for a good second... my fuel pressure kicks up to 50 psi then drops fast down to 20 and stays. my fuel system is a bbk fuel pump and afpr with accel 19lb injectors all a lil over a year old only problem ive had with it is that i only read now 1/2 to full tank of gas always guessin... any help to keep the pressure??? thank you...
-Tim

fyrebird68

iTrader: (1)

Fuel pressure should go to 40+ psi and pretty much stay there even before you start the motor. Looks like a leak in the fuel system. If you don't see or smell any leaks then its getting back down into the tank. My first guess would be fuel pressure regulator. Pinch off the return line and start the pump again - see if pressure stays up.

Alternatively it could be going back out the fuel pump. That would mean a bad pump.

burnout88

Did you ever change the fuel filter? Could be clogged.

86firebirdta

fuel filter is new.... i took off the fuel rails i found my leak but it was not getting any fuel into the cylinders, but i had 40+ psi at the rails and the fuel was there. could the regulator be bad jus bypassing it and go straight back into the tank??? i took the return line off and stuck a bolt at the end and tried crankin it so much pressure the gas forced its way through the bolt. im thinkin the regulator gettin the holly one...

fyrebird68

iTrader: (1)

wow. fuel under pressure at the rail but no fuel to the cylinders? That would mean the injectors aren't firing. Are your plugs showing any wet fuel?

When you plugged the return line did you get good pressure that stayed?

You may be chasing more than one problem here - losing fuel pressure AND no fuel to the cylinders.

86firebirdta

im keeping pressure now... there is fuel in the rails but there is no fuel in the cylinders... did a noid test the injectors pulsed but nothin at all on the plugs jus covered in soot... its hard to believe all injectors went bad over a 5 month period of siiting, but wat about the fuel pressure regulator could it jus be passing that goin right back into the tank or wat??? my plans are cleaning everything as good as possible throwin it back on and tryin again.

fyrebird68

iTrader: (1)

If fuel pressure is holding the regulator and pump are working. The injectors may have a blown fuse or the ECM is not commanding them to fire.

Check the fuses for the injectors.

86firebirdta

fuses are good and the computer is new.

fyrebird68

iTrader: (1)

Probe the + side of the injector to make sure +12V is making it all the way to the injectors. pink/black wire should have 12v when the ignition switch is in 'run'.

Make sure the ECM is sending a signal to fire the injectors. Dark blue and dark green wires should pulse to ground when the injectors are fired. Use a test light or o-scope to check.

86firebirdta

yup i got 11.17 volts to it and when i cranked the car the test light pulsed.

fyrebird68

iTrader: (1)

... and you are able to get the car to run briefly with a shot of carb cleaner?

86firebirdta

yep starts right up idled for 15 seconds really smooth then nothin.

fyrebird68

iTrader: (1)

...and your fuel pressure stays at least 40psi the whole time?

86firebirdta

yea im having it jump in between 40-50

fyrebird68

iTrader: (1)

I am stumped. You have spark, fuel, and air. You have good fuel pressure, the injectors are firing. The car runs with a shot of starter fluid. I can't imagine you have EIGHT non-firing injectors.

This is a wild guess, but maybe somebody can validate it for me. Is it possible to fire a fuel injector without it being installed in the rail? Maybe you could disconnect one, or connect a spare one to make sure they are in fact squirting fuel when told to.

86firebirdta

i took 2 of the driver side injectors out of the ports jus to see if they were spraying or anything.... nothin when priming nor cranking over.... hard for me to believe too that all injectors would be bad especially when they were fine when i took them off... if the diaphram in the regulator is gettin bad would it not seal and jus bypass to the tank because thats the only thing in the system that doesn look too hot.

UnderCover89TBI

iTrader: (25)

Let's hope so. car has had me stumped for awhile...