kd5rcx

Hi All!

Original problem:
It ran fine. Sat for about a week unused, then crank but no start. On startup the first time you hit the key, you might hear a few cylinders fire, but only on the FIRST revolution of the motor. After that there would be NO firing of the gas in the cylinders. Ether didn't get any results, neither did spraying fuel in the throttle body or even directly in the cylinders.

1993 f150 with a '92 f150 5.0

I had three capable people go behind and check (after I checked and rechecked ) the timing, fuel pressure, coil, and ignition. I tested the TPS, ACT, IAC, ECT, bought and swapped computers(old), tested portions of the harness. I started to change the hall effect in the distributor and found a problem. I finally found rust in the base of the distributor! As the engine started to turn over, on the first revolution, before the rust got stirred up, a few cylinders would actually fire. After the rust got stirred up the cylinders would fire in order, but the injectors fired after the plugs did. No fuel ignition and the spent fuel would just be pumped out on the exaust stroke. I still don't see why the ether would not hit...

New Problem:
Crank No Start with Flooding
I think it was .975 volts on the TPS throttle closed. Should I try for .90? EGR is clean,vacuum opens it ok, resistance checked out on the sensor on top. ICV voltage tested ok, I even pulled it off and watched it actuate ( I didn't see a test that actually tested it ). New ACT tests in range. Sprout in, sprout out no difference.
Haven't put a light to it. Or I should say I can't see the light on the harmonic balancer. I will probably paint the HB dark and use white for the markings. But mechanically I should be within 4 degrees of TDC.


Scared the cp out of me.... I had left the key on to run a test and forgot it was on. For some reason the fuel had only pumped up to around 25 psi when the key was turned on. I had pulled the fuel relay. I had a remote switch on the starter relay. I had already bumped it a few times to clear the fuel from the last attempt. I wanted to bump it one more time. When I hit it.... the dn thing started and ran until the fuel rail went dry! Occasionally I can get it to run for a few seconds with the throttle wide open, but it's running so rich, even that won't last.

For fun I wired the old and new ACTs in series. It ran for about 40 seconds that time but still flooded out. And traded EECs again for kicks.

As kd5ckp says
There it is and Here we are


Thanks In Advance
kd5rcx
Pat

kd5rcx

Any Ideas? Ya'll make me feel better.... gimme somethin'.

qdeezie

MAP Sensor???

cody5127

Well if ether won't even hit, sounds like spark issue to me bad dist or somethin

autocar

Do the plugs come out wet? I know on mine that it seems like the injectors leak into the cylinders once you shut it down. I know they are electronically controlled but they may be just flat worn out. I priced a new set for about $450.

It might need a new ignition module? Can you put a tester on it a read some codes?

kd5rcx

The map tested, if I remember, .15 to .18 as I pulled vacuum on it. And it held vacuum. Assuming my meter reads in Mhz, that should be right.

Gimme some odd signs of the ignition module going bad. I have constant spark at the distributor. Doesn't that rule out a bad ignition module?

I've fixed the issue of no "detonation" in the cylinders by cleaning the rust out of the base of the distributor (just a miniscule amount, but enough to mess with the hall sensor.), and replaced the hall sensor since I had it apart. You couldn't see any rust or other debris from the top of the distributor.

But for giggles I do need to spray fuel or ether in the intake to see how long I can get it to run on a Small amount of fuel.

Now my problem is flooding!
If the rail is starved of fuel, it will run for a few seconds, until it finally floods again. Again, for fun I ran two intake temp sensors in series to give it a bucket load of resistance and it ran, rich as all get-out but it ran for about 40 seconds

And Oh yes the plugs come out wet! I left the pressure gauge hooked up for some time after attempts just to see if I had leakdown. No go. It holds pressure for a day or two after!

The Big question: What signals the computer to adjust the amount of fuel to the injectors, especially on startup?

kd5rcx

Another just for fun. I pulled the fuel relay; turned the key on; bumped the remote start and touched the relay to the socket just long enough to keep about 25psi on the rail. She ran! I'm gonna try to put the old regulator back in.

Still tryin'

kd5rcx

This gentleman is also havin' crank no start issues.

https://www.f150forum.com/f10/95-f15...-start-145214/

But please give me some ideas too!

kd5rcx

I'm over pressure on my fuel system. I think somethings plugged. Arrg! Back trackin' the previous owners work... The front tank went bad. He broke the lines in two to the rear tank; installed fuel line from the filter back to the rear tank; installed a filter in the return line ( and I think reamed it out ) to be able to run fuel line to the rear tank return.

Gotta be done anyway so:
I dropped the front tank. Arrg! again. A quarter of an inch on rusty sludge in the bottom of the tank! I didn't do a perfect cleaning of the tank, but I removed all of the rust, replaced the fuel filter, corrected the lines... We'll see what our pressure is this weekend.