My 89 Formula is a giant blue headache!! I finally got everything
I needed done to it finished. My friend started it and it died. Out of gas. Ok, put more gas in it and now the best I can get out of the injectors is dripping. I have tried replacing the O rings that hold the injectors in the bowls and nothing. Before this I replaced the fuses for the fuel pump, the relay, the fuel pump; have broke the top cover; got a whole TBI unit off anothe car and replaced the one on the car to no avail. Please tell me what to do as I have no idea what to do next.

 

Everything worked fine before we ran it out of gas

 

Did you check fuel psi? should be 9-13 psi. Just because fuel comes out the line does not mean its going to run. Does your car have spark? Too low psi get a new fuel pump, no spark and no fuel I would say modual in distributor. You can make a cheap signal test for injector with a led light.

 

I have heard that sometimes a fuel pump will die when run out of gas--the gas cools it, plus it will suck crap off the bottom of the tank. Best to keep it at least 1/4 full. Do you get fuel pump hum when you first turn the key? Check the fuse by the battery, should be a little black plastic cap on the end of two wires, hanging in the fender by the battery. Good luck, and keep us posted. Had similar troubles, was the fuse.

 

Yeah, fuse next to battery is good; all fuses in fuse block good; can get the pump to work with key and or Jumping it through the
diagnostic port and a hot; the fuel pump has no road miles on it
and less than an hour run time as I just replaced it; car was running great until out of fuel; if fuel gets in motor for several different reasons; pouring spilling.. etc the motor runs; I do have spark; could it still be the module?

 

Can you hear a constant clicking from the injectors while cranking? If not, or just maybe an ocasional faint click, it sounds alot like the VATS is still giving you trouble. Does it throw any codes?

 

I haven't got it to run long enough since it ran out of gas to throw a code; but the security light does come on when you turn the key then goes off. As far as clicking I'll can't hear it over the starter; I played with the car some more after the post and checked the ignition module connections. The injectors are trying to fire as they drip when I turn the key to start; my next guess is fuel pressure. It's a new pump but that doesn;t mean anything; If I break the tab that holds the cone in the fuel pressure regulator will it then become adjustable? Maybe I need more pressure; or maybe I just need a different car... Is it possible to have air in the fuel line? more insight is greatly appreciated!!!:hail:

 

I have had problems with fuel pumps from a place with a A and a Z in the name did 4 in a row that ran for a few mins and just died.

 

Yes it is possible to have air in the fuel line or your strainer on the fuel pump may be clogged with debris that was in the tank when you ran it out of gas. It sometimes takes about 4 to 5 primings of the pump with the key to get good pressure to the injectors after you run out of gas or change the fuel filter.

 

how about the fuel filter have you changed it since you had the problem???

 

Yep, Filter. fuses, relay, pump and strainer. That's why I am so stumped; I let the pump run for about 30 seconds and that didn;t even help; I've tried two different sets of injectors; could a gasket in the throttle body cause this much trouble?

 

I doubt its anything wrong with the tbi itself. You can manually check teh injector circuit by grounding the switched negative side of each connector. The injector should open. Consult a wiring diagram, though, before you ground anything. Id also check the fuel pressure at this point to make sure you actually do ahve pressure and there isnt a problem with the pump or the installation.

 

Stay with it, you'll figure it out. If not, consult a mechanic--I had to get a mobile mechanic to help me out once, and he solved the problem in minutes. No, you don't need a different car, just need to find whatever is holding you up, then you will be on the road again. It's such a good feeling, getting your car fixed after it's been down.

Also, I'm pretty sure there are tech articles on here for diagnosing VATS problems, and doing a VATS bypass. There are only so many parts involved in starting your car, so by process of elimination you should be able to figure out what's not working. If not, call a mechanic and be done with it. Good luck!

 

since you said you have pulled the injectors out i would say for just for grins,pull them again and be sure the nipple in the injector body is fitted into the hole in the injector pod,very simple mistake!may not be the problem but noone has covered this...

 

Have you hooked up a gauge to the feed line? Try that to rule out the feed fuel line being clogged up.

 

As far as I know there is no Schrader valve to check pressure; so
how would you do so on a TBI??? Really beginning to think it is pressure.
Checked the injectors and they were in the right spot.
I solved the Vats thing a while back; funny long story;
traded a 83 Z (not my L69) for this car; no keys, no title
- bought keys found out it was a Vats car
- Got Vats module and key from a donor and still wouldn't crank
- Got new ignition switch and pushrod for ignition switch as some
dillweed cut it; would crank but not start
- Long process of changing pump, relay, fuses, and filter; car
finally ran like new
- Put on exhaust system as same dillweed cut it off
- Finally got all paper work done to submit for title
- While driving my wife's Altima was rearended by a F250; never
stopped as he was adjusting his seat (Thank *** not my
Camaro) Altima is dead
- Now had a donor tag
- Put on tag and insurance, car ran out of gas getting it off
jackstands
- Now I am here; I have drove the car a total of ten feet with the
help of my friends Blazer, my wife is ticked, I'm frustrated
and Lord help me I work for an insurance company and am
really considering insurance fraud!!! Just Kidding!!
Sorry I know this was long and off the point, just needed to vent!

 

Unfortunatly, **** does happen. Not much to be done there, especially if its some car that someone did some backyard re-engineering to it. As far as the fuel pressure gauge, you can cut (cleanly of course) the larger feed line and plumb a fp gauge in line. If its got pressure and theres good power available to the injectors, then that leaves the ecm as the most likely culprit as the cause for no fuel being delivered.

 

I just played with it some more, fuel pressure has got to be it;
I just changed the fuel pressure regulator diaphram; no change.

Once I get the psi checked I will let ya'all know. It sucks because the car is in the best shape I have ever seen an F-Body; except for the obvious; no cut wires; all options work; nice interior etc.
Thanks for all of your help. It has narrowed down alot.

 

I have to agree with dimented24x7 about the ECM. If you getting nothing at the injector connectors then it is either the injector drivers from the ECM or the wiring. Now you mentioned getting a VATS module and key from a donor car. Have you checked the wiring from the module to the ECM. It is a blue wire that should go to Pin "B6" of the ECM. That is the fuel injection signal wire from the module to the ECM.

 

get a led and wire it on an injector when you crank it it should flash with the injector firing, it will let you know if the ECM is firing the injector

 

Try to plumb the test light in parallel with teh injector so you can see if the ecm really can fire teh injector. One common mode of failure that Ive heard of is that the injector drivers fail and cannot drive a load. They can, however, drive a test light leading one to believe that the driver is still working when in fact its not. This is less likely then a pressure problem or a VATS but its still a possibility.

 

Got a wild hair and got CODE 54??? Can the TPS cause the injectors to drip heavily instead of puff????? What about the MAP??

 

Well.... I think it came on because I was desperate and took out FP relay yesterday to see if there would be any change; also I have now run the brand new $90 battery down trying to start this POS. Will recharge and retry codes

 

The code 54 is low fuel pump voltage/faulty relay. May have been set if there was a large voltage drop from a dead batt. or that may be your problem right there. Id back probe the fuel pump relay connector and check the fuel pump voltage to make sure its got +12 volts or whatever is available voltage wise going to teh pump when its supposed to be on.

EDIT: Dont have any wiring diags. to show you. Maybe someone can post them?

 

I don't know if you've figured out a way to test the fuel pressure. If not, take a look at this : http://www.actron.com/product_detail.php?pid=16175

It would appear the adapter is available separate from the gauge in case that's all you need.

You asked in an earlier post whether or not TPS or MAP could be causing the problem. A "high" TPS signal could put the ECM in clear flood mode during crank such that it would fuel at a high AFR (usually around 20:1). But, I think this only applies during cranking. Once the engine actually starts, the AFR would follow normal schedules. You mentioned you are able to run the engine if you manually spray fuel into the TB. If the ECM didn't take over and run normally after a few seconds, this probably isn't the problem. As a quick test, you could disconnect the TPS connector. While this will ultimately set a code, it would also insure you're not in clear flood mode. I don't think an incorrect MAP signal would cause the problems you're seeing all by itself.

You can also check to make sure you have +12V at one of the injector terminals on each injector with ignition on. The ECM just grounds one side of the injector. It would be a real kick in the pants to find the problem was with the injector electronics rather than the fuel pump after all your work!!

 

If he lets me know what wiring harness (or harness's) he has, I can give him the schematics for it along with the trouble shooting chart for the code 54.

 

Like said above check the injectors to make sure they have +12 volts and that the ecm can drive them. The clear flood only applies when cranking, once the motor starts, it runs like usual. Found that out the first time I actually tried it. In mine it has to be wide open to do the clear flood and the motor revved to 6k as soon as it caught.

 

Thanks to all for the info. Tomorow will tell the tale. I'll keep you posted, stay tuned!

 

Well......... I figured out the hots and the grounds for the injectors
hooked a jumper wire to them and they click and open and let the fuel pour out. The resistance on both injectors is 1.5 ohms.
Voltage at the fusebox for injectors is 12V; Voltage at the Fuel pump connector is 12V. Voltage at fuel injector connectors would only spike to 2.56 V, but I am using a digital multimeter so the lag on the reading never catches to the pulsing of the injectors. I changed the fuel filter (Again). I changed batteries for one with a full charge. Nothing has changed. Injectors start with strong drip
and then go down to light drip as you let the starter turn. Fuel
Pressure testor is $40+ at Autozone. The spending for this didn't
pass through Congress (Wife) for this week. Maybe next week. Definately want to make sure pressure is bad before I take the car apart (Again). ODD THING HAPPENNED THOUGH!!!!!!!
When I disconnected the fuel filter I thought "I'll just let this 'lil bit'
of gas drain out of the lines before changing it'. About two gallons later I changed it while still flowing as fast as it started; I
thought with a electric fuel pump this shouldn't happen. It was definately taking gas from the tank. Could this prove the pump is
bad or loosing pressure somehow???

 

You could jump the fuel pump pin on your aldl port, I'm not sure which pin this is, but it will make the pump run all the time and then you could try starting the car with the pump on for sure, I even check to see if there is pressure in the line by pinching the line with my fingers and feeling or listening for the pump to load up. You can feel the pump through the rubber line. If you have pressure then it's ecm related, ie. bad injector drivers.

 

When you changed the fuel filter did you relieve the pressure in the tank and line first by removing the gas cap?

 

Yep; I did leave the cap off also.

 

The fuel filter is lower then the rest of the tank. The gas will siphon itself out when you disconnect the filter. Important little fact that I overlooked when I changed mine. The fitting was pretty messed up from being cross-threaded and it took me a minute or so to get it back on. During which time the gas just kept coming out and pouring all over me. 'Nother important fact thats often overlooked is that gas causes severe chemical burns. Nothing like some blistering and peeling skin to top off something stupid like a filter change. If I ever change it again, Im definatly going to drain the tank beforehand.

 

So electric doesn't matter as far as siphoning goes then. Well
I'll get the PSI guage w/ the TBI fitting Friday. I guess we'll know then if it is the pump or not. If not I will be at a loss. I know there have been alot of posts for this thread pointing to the computer; but as I've said; everything was great until it ran out of gas. I am not getting a code 55 or any other eroneous codes like I did on my Z. I hate to say it, but I hope it is the pump...

****************************************************
One item of interest, When I pulled the old pump out the 1' piece
of hose that holds the pump to the line was almost ripped in half.
Is this common? The car does have 138K miles.
****************************************************

 

While that is not exactly common, it would explain some (if not all) of your problems with fuel pressure.

Btw, my question about the gas cap was not meant to be derogatory. It is something that a lot of people neglect to do because they are unaware of it.

 

I found that one out the hard way, too. Left the tbi off and the change in temperature and pressure caused about 5 gallons of gas to blow back out through the lines.

 

Originally posted by Trickster

Oh I know, the whole crazy smiley thing was just because I am sooooo p/o 'd at this car; I have had it since Jan 13 of this year
and have not seen any fruits of my labor. Trust me, I would not be a smart a$$ to someone trying to help me. Sorry if it seemed that way.

And the rubber thing was on the old pump; I haven't taken the tank back out yet to see WTH is wrong; waiting on the psi guage before I go through all of that again. Congress (wife) did approve money for the guage this Friday though!!

 

i hear that one...


if mama dont agree then it dont happen...

 

Do you have injector pulse at all?
If your Throttle position sensor has shorted out it will cut the voltage to the throttle bodies.
I would check for injector pulse.
I've seen this problem a hundred times.
try swapping yout TPS and see what you come up with.

 

I'll try it; the injectors are getting a pulse; is it possible they are not getting enough of one?

 

Man, I hope yall figure it out, i am having the same problem on a blazer we just swapped a 454 into, ran perfect before we did it, now fuel pressure and spark, but no injector pulse.

 

Well....... TPS wasn't it. Bought the fuel pressure testor with the
TBI adapter; It is nifty, keen in a groovy, cool sort of way. Swivels and everthing. It is idiot proof too; only fits on the inlet line.

I HAVE NO FUEL PRESSURE

Stupid car.

Will go through the tortuous process of taking out the fuel pump, again. This time I will probably cut a hole in the rear panel just in case this ever happens again; any thoughts??? Anybody know who at GM I can put a curse on??

 

I have heard of cars not starting after running out of gas--fuel injected cars--sometimes air gets in the system, or the pump loses its prime, or burns out from being dry. I don't know, but I have also heard of the problem remedying itself after a few tries at starting with a full tank. Also, don't hesitate to call a mechanic familiar with these cars, might be something minor overlooked. Good luck!

 

Have you tried sending 12 volts DC through pin "G" of the ALDL and ground to see if the pump will run? Just a thought? The problem might be in the fuel pump relay or the ECM or the wiring.

 

Usually the fuel pumps will last the 'expected' life of the car so I guess they didnt take easy removal into account. Good to hear that you found your problem.

 

Now, like theyve pointed out, Id be suspicious of problems with other things then the pump if it had zero pressure.

As for running dry, that will definatly kill a pump. The fuel circulating though the pump is what cools it.

 

I have a feeling that the computer is trying to point your problem out to you in its own little way.

 

Yeah the car has a new Fuel pump relay. Bought it before the first fuel pump change.
And I can get and hear the pump run when I plug into the ALDL
port and a hot. That could have been part of the problem to begin with. I used that thing alot when working on the car over the summer.
Evidentally I hurt the pump somehow and it runs but not w/ enough pressure. It was probably the numerus times my friend and I intially tried to start the car before I realized it was out of gas; guage is haunted.

Thanks again for all of your insight and help. I'll post again either this weekend or next when I change the pump.
:hail:

 

I have one more question here and I doubt that it happened but stranger things have happened. When you changed the fuel filter, which way did you have the arrow on it pointing? The reason I ask is because the fittings are the same on both ends. Just a WAG thought.

 

I'll check and see.