fuel pressure problem?

HELP! guy's i just picked up a 87 4 cylinder fiero that has been garaged for 7 years.It had a bad fuel pump . Replaced on problem, but now when i turn on the key to start, the two second run of the fuel pump completely fills the carb with fuel and floods it out. any ideas ?

sorry, that happens when you get old.  i replaced the injector with a new unit.

Newbie

I recently was able to get my 84 Duke running after several "what could be wrong" situations. My task was relatively easy since I had a operating and compatible parts car, so rather then diagnosing problems to death, I merely installed the spare complete TB from the parts car. The car was no better for that, but I at least knew what the problem was "not".

In your case, I suggest that you disconnect the injector electrical conductors and see whether it still floods. If it does you can be "certain" that the problem is with either the injector itself or the injector gasket. With the injector disconnected fuel should not flow into the TB. That is what it says in my 84 service manual.

When I first looked at your posting I wondered whether you had accidentilly installed a V6 (much higher pressure rating) fuel pump. However our own "captain fiero" has a lengthy posting on Pennock's where he describes his successful installation of a V6 fuel pump onto a Duke.

One of the limitations of this website is that there is no provision for identifying the location of a member at the time of registation, so unless you do so in your posting the "local" members have no way of knowing where you are.

If you have not solved your problem by now and want to do another posting, please indicate where you live.

If you decide to merely change out the TB, please check www.fierosails.com and look at the "interchange" topic since the Duke TB will not intechange for all years. 

Based upon my experience (see page 2 of my "Indy" posting) you might find it useful to check the fuel pressure since the 10 cent rubber hose connector between the fuel pump and the steel tubing is quite prone to failure. That probably is not part of your immediate  problem, unless you have two fuel issues. 

If the fuel pressure is signifcantly lower than the the standard range of 9 - 12 psi (mine was only 4 psi and was not sufficient to run the engine for more than a few seconds) you might just as well bite the bullet and spend a couple of hours (or more) dropping the fuel tank and replacing the 10 cent hose. One Pennock's contributor suggested installing hose clamps and that is what I did since my car would have run for some additional time until is stopped dead on a highway when "sponge" turned into "holed".

Cheers

Gary (another newbie) in North Vancouver.

 

convenient way to n e My gues is that you will find that  

Thanks for the suggestions , I went out and disconected the electrical conector to the injector , i still had fuel going into the TB but not nearly as much as with the injector hooked up. It did occur to me that the previous owner may have installed the wrong fuel pump , he told me this problem only surfaced when he tried to test the new fuel pump. thanks again- g

Can it be a bad fuel pressure reg? I replaced the injector with a brand new unit.

How about you re-install the "old" injector, making certain that it is correctly seated and sealed? Or did you have the same problem with the old injector?

Then check the fuel flow once again with the electrical connection disconnected. 

If that does not work, please get back to us, because there are other possibilities.

You could look at the shop manual, but if it is anything like the 84 version, it will take more effort to figure out how to use the manual than it will take to solve your problem.

However, the first thing that I would do if the above does not sort out your problem is to check the fuel pressure. If the pressure is high (the V6 fuel system presure is about 45 psi) there are other possibilities that include:

• a pinched fuel return line.
• defective presssure regulator in the TB. Potentially that could contribute to increased internal fuel leakage or bypass since the normal Duke fuel pressure is only about 10 - 12 psi.

Gary

Woah woah woah, I wouldn't have necessarily bought a regulator until I knew that was the issue. If you have a fuel pressure gauge, hook it up to the outlet on the rail and see what you get. Then disconnect the vacuum line and see if it goes up, while still staying within spec. As the other gentleman pointed out, there's more reasons why it could still be puking fuel (New injector also broken, gasket to injector not sealing, pinched line before the regulator, contamination in the injector). Hopefully the regulator solves the issue, otherwise you're going to be a touch annoyed with yourself.

Ok...I want to make sure you understand what I meant earlier.

You need to measure the fuel pressure of the regulator you have now BEFORE you go and replace it.  Reason being, you need to know if your injector has been damaged.

If you simply replace the regulator and indeed both your injectors are now buggered, it will leak anyway and you won't know what's going on.

The Dawg