Question about 1986 Pontiac Fiero

1 Answer

1986 pontiac fiero won't start, changed fuel pump and relay gas coming up, but no spray from injectors

Posted by on

1 Answer

  • Level 1:

    An expert who has achieved level 1.

    Hot-Shot:

    An expert who has answered 20 questions.

    Corporal:

    An expert that has over 10 points.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 33 Answers

Actually the injectors don't spray "all the time". They pulse open for a few milliseconds then close every time they are grounded by the ECM. The distributor has a pick-up coil (Variable Reluctance sensor) that provides an A/C (Alternating Current) pulse every 120 degrees of crankshaft revolution to the Ignition Control Module also contained inside the distributor. The I.C.M. amplifies, rectifies and passes along the pules as a +12V square wave to the ECM. The ECM uses these pulses to calculate RPM and determine when the engine is rotating vs. stopped. Together with this information and more from Coolant Temp., Throttle Position, Manifold Pressure and Air Temp. the computer constantly 'looks up' what the appropriate amount of time it should pulse the injectors for to deliver the required amount of fuel.
With that in mind, the injectors are supplied with +12V via a 3 AMP fuse labeled INJ 1 for 1 bank of 3 injectors, and INJ 2 for the 2nd bank of injectors. Make sure your injectors are getting +12V whenever the key is ON or they wont fire (or at least 3 won't).
If all 6 injectors have +12V and you have fuel pressure (checked by pushing down in the center of the Schrader (tire valve stem looking thing) valve and fuel SPRAYING out, and your still not getting fuel it is probably because the injectors aren't pulsing. They are probably not pulsing because the ECM is not receiving any reference pulses from the distributor. If you have spark then you are producing reference pulses.
I hope some of this explained from an actual '86 Fiero GT 2.8L V6 owner/mechanic will help narrow down your problem.

Posted on Aug 11, 2014

6 Suggested Answers

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

  • 625 Answers

SOURCE: fuel injector over fueling

all the injectors are supposed to constantly spray fuel when the car is runing,
but on the hard to start it might be a worn out fuel pump or
a leak on the fuel pressure regulator, unplug the vacium hose from the regulator and if there is any fuel at all then regulator is not good

Posted on May 29, 2008

  • 625 Answers

SOURCE: cold start valve problem

if you have an electric cold start valve make sure to unplug it and if keeps apling fuel with electrical conector unpluged that means the valve is not good, but if not then you have an electronic problem, possible a bad cold start sensor or cold start module or cicuit problem, and might be a time to take it to an electrical shop

Posted on Jun 17, 2008

emissionwiz
  • 75822 Answers

SOURCE: Fuel Pump Relay Switch

Underneath your hood, behind the passenger side headlight, behind the core support, is a bank of 2-8 relays. One of those relays is the relay needed for your fuel pump. There will also be a fuel pump relay fuse located there. The relay designation should be on the cover of the relay compartment.

Posted on Jan 03, 2009

  • 1 Answer

SOURCE: f-150 xlt lariat...5.0 starts..runs about 5 minutes, quits

could have plugged injectors

Posted on Feb 04, 2009

luv2tango
  • 36 Answers

SOURCE: My 95 Pontiac Bonneville is not getting gas I've

What you need to do is have an assistant turn the key on (not try to start, just turn the key on) while you have the gas cap removed and your ear down by the gas tank fill tube. When they turn the key on you should hear a whirl only for 3-7 seconds. If you hear nothing more than likely you will need to change your fuel pump. Attempt this test on several tries at different times several hours apart before you **** your tank out to give it ample time to relieve any fuel pressure that may be built up thus causing your pump not to respond. BUT, if you are not getting any fuel you are not getting any pressure built up so it should be making some sound. How many miles do you have on this vehicle? 9 times out of 10, sorry to say, you'll be replacing the fuel pump. It sounds like to me that you have thourouly checked every other possible thing. Good luck my friend. Let us know how you come out.

Posted on Mar 09, 2009

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

No fuel spray from injectos


1986 chevy s10 2.5l no gas coming from injector. - S-10 Forum

www.s10forum.com/.../1986-chevy-s10-2-5l-no-gas-coming-from-inject...
Sep 2, 2009 - 24 posts - ‎7 authors I have no gas coming from my injector it a 1986 chevy s10 2.5l I have replaced the fuel pump,oil pressure switch & I checked and oil would ...

Oct 12, 2015 | 1988 Chevrolet S-10

2 Answers

84 pontiac fiero injector want spray on crank up


What have you done to correct the problem?
have you check for voltage at the injector?
Do you have fuel psi at the rail before and after the fusl regulator?
Lee Davidian

Mar 11, 2011 | 1984 Pontiac Fiero

1 Answer

86 olds calais only starts if i pour fuel in throttle body fuel pump is working, is their a fuel filter by the throttle body or could it be a relay


The fuel filter is under the car, in-line. If the pump runs, it wouldn't be the relay. When you try to start it, can you see any gas spray from the injector? You could have a bad injector. Check for power going to the injector.

Mar 11, 2010 | 1986 Oldsmobile Calais

3 Answers

I have a 88 Fiero GT V6 that has sat for over a year without starting. I put in 5 gallons of gas, and used starting fluid. Starts, but only keeps running while fuel is poured into intake. I suspect water...


1) Running fuel pump to remove water from tank will likely not empty it all, but it might help. Will still be some liquid in bottom of tank.

2) More than likely, the gas has gummed up and is no good, While your draining of the tank will help, may still need to change the fuel filter and clean the injectors. The ability to keep engine running while pouring into the intake is a good sign, but mayfind that more parts need to be cleaned and replaced prior to solving the problem.

Oct 19, 2009 | 1988 Pontiac Fiero

2 Answers

86 suburban won,t start,fuel pump ok.injectors won,t punp gas into carb.


did you change the fuel filters? One in-line and one in carb

Aug 17, 2009 | 1986 Chevrolet Suburban

2 Answers

Too much fuel pumped into the carb. What to do?...adjust?...set?


The idle air control valve may be at fault, also the throttle position sensor may be telling the engine th wrong information and sending too much fuel, a couple other ideas come to mind but I not an expert. A faulty injector is one of them.....I another idea that may help as well: Vacuum Leak: The ECM will try to compensate for leaks up to a certain size. This will cause the ECM to compensate and possible send too much fuel to the engine...???? Good Luck

Mar 15, 2009 | 1986 Pontiac Fiero

2 Answers

Engine won't start


Check all of the battery terminals and cables and check the wires on the starter/selonoid, start from the battery and follow the cable out and check all conections , clean and tighten them and if it still does it the starter/selonoid is bad and needs replacement...
 
also check the ignition switch and ignition module.

Mar 11, 2009 | 1986 Pontiac Fiero

1 Answer

1987 pontiac fiero 4 cyl does not start, over fueling


its most likely the cpu fuel management this could cause the car to be running to rich

Mar 02, 2009 | 1986 Pontiac Fiero

2 Answers

I just bought a 1986 fiero 2.8 v6 when i start the car it run about 5,000 rpms and will not come down to an idle


Check the EGR tube that bolts to the bottom of the upper intake (close to the throttle body) to the EGR Valve for cracks. Also check for Vacuum leaks. Also have the cold start system check for problems. The COLD START INJECTOR SWITCH might be bad.(The cold start injector switch activates the cold start injector on all V-6 Fieros. This switch turns on the cold start injector on initial start up to get the engine to start quicker and run smoother when it is cold.)

Jul 30, 2008 | 1986 Pontiac Fiero

Not finding what you are looking for?
Cars & Trucks Logo

611 people viewed this question

Ask a Question

Usually answered in minutes!

Top Pontiac Experts

yadayada
yadayada

Level 3 Expert

75822 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

8202 Answers

Are you a Pontiac Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...