I am currently working on a 1987 4 cylinder 5 speed. Won't start without starting fluid, and it takes awhile to get running. I have replaced the spark plugs and fuel relay sensor,
Is this a:
cold start sensor- but even after it starts it doesn't continue to run without spurts of starting fluid
oil pressure sending- not engaging the fuel pump
Pulsator issue
Coolant Temp Sensor
Intake Air Temp Sensor
Fuel Pressure Regulator
Mat Sensor
IAC- I twisted the pintle clockwise because it is stuck all the way out in order to shorten the length and the idle RPM's dropped! Am I on the right track here as it may be an IAC issue?
Injectors- Due to the fact the car stays running if I spray starter fluid
Any input is greatly appreciated, thanks in advance!
------------------ 17 years later and I am a Fiero owner! 1986 GT Automatic 1987 4 cylinder 5 speed
You refer to injectors. The 4 cylinder only has one. It might be that the injector is bad. You can remove it and clean the screen. Be careful not to drop the O-ring or any of the parts into the throttle body.
Best thing to do is raise the car on jack stands, slide underneath and have someone turn the ignition on. If you don't hear the fuel pump run, that may be part of the problem. I'd change out the fuel filter while under there, too. You should also be able to hear the fuel pump relay click when you turn the ignition on. If not, then it's faulty.
IAC's come in two designs. One has a smooth round shaft that the pintle is mounted on. That one can be retracted by turning the pintle. The other has 2 slots, one on either side of the shaft. That one will be damaged if you try to screw it down. It must be wiggled side to side while pressing inward on it. Be sure your setting is 1 1/8 inch from the tip to the base where the gasket would set against the body of the IAC.
The oil pressure sensor is a backup for the fuel pump relay. If either is working and the fuel pump is good, you should get fuel.
700 TBI only has 1 IAC design I know of. older 300 has two. 700 injector is very tough and hard to kill. Even dirt will have hard time to plug it if main filter is blocking dirt from main tank. GM design the 700 so dirt etc won't block the injector because most dirt will pass thru the fuel meter side of the unit.
Check fuel pressure. Apple 12v to Aldl G for the test. TBI Test Adaptor low pressure like means: bad power/ground to pump. See my Cave, Electric Motors bad pump bad TBI regulator stuffed fuel filter
Injector test, need to find Noid light and volt meter. check injector for 12V when key is on. Noid light will tell you if ECM is grounding injector. (light will blink when ECM send the signal.) Volt meter will work but if you short the pins etc can blow fuses even kill ECM. No signal likely mean ECM is bad or maybe ignition problems. ECM won't send injection signal if DIS has problems. Most times is ECM is bad because internal problem to ECM, mostly heat problems. See my Cave, ECM Heat
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Assuming you have good gasoline in the tank, if you cannot start the car and keep it running without starting fluid, you should check the fuel pump first for proper fuel delivery. The fact that the car does run on starting fluid tells us that you are at least getting spark so your ignition is at least working well enough to ignite the air/starting fluid mixture. Unfortunately, GM did not put a schrader valve on the fuel line on the Duke so you need to make up a tee to use a fuel pressure gauge. You should have between 9-13 psi when you turn the key to run position. When you crank the engine, do you smell gas at all? Do you hear the pump run for a couple of seconds when you turn the key to the run position?
When the key is in the run position I can hear the relay click, the fuel pump engage, and when I try an start the car it turns over just fine. It won't start for some reason...Using starter fluid works every time though.
The car will start and I can utilize the gas pedal, but once I release my foot from the gas pedal the car dies.
So the car won't start without starter fluid, and after it starts if you were to stop or remove your foot from the gas pedal it dies. WShile your foot is on the gas pedal you can press down and it works fine.
All gauges work as supposed to with correct readings as well.
------------------ 17 years later and I am a Fiero owner! 1986 GT Automatic 1987 4 cylinder 5 speed
I bought the car and the gentleman said it had a problem for him starting which was unusual. He said it started just fine every other time, but it has sit for a long time.
He drove the car to meet me and I looked it over and it was about 15-20 minutes I took it for a test drive and it started just fine.
I drove it home, and would go out for the following 3 days to start the car an let it run. Day 4 it wouldn't start without the starting fluid being used.
------------------ 17 years later and I am a Fiero owner! 1986 GT Automatic 1987 4 cylinder 5 speed
Consider changing out the fuel filter. It's cheap and after sitting for a while, you never know what condition the tank is in, especially if it sat with a dry or nearly empty tank. Fuel filters will allow some fuel to get through if enough demand is placed on it, even though they're badly clogged. Also, if the engine has backfired with you, the Dukes will sometimes blow the vacuum line for the MAP sensor off the bottom of the air filter housing. It's a hose that's not visible in a normal engine view so it can be overlooked. This can dramatically affect the fuel pressure regulator's ability to deliver enough fuel.
And quoting you from the other thread "So being a newbie vrs a veteran has clout on this forum? I used to have the mentality as I am a Retired Army Vet........But I guess you guys will relaze knowledge and wisdom are two different educational aspects a person holds. "
It makes no difference how long you've been a member. You can see that lots of people are willing to jump in to try to help. People with V6's will probably tend to get more and faster responses because that seems to be the most common engine we have. Dukes are probably in the minority as far as numbers go, so many of us aren't as familiar with them. For example, I've owned 7 or 8 Fieros and only one of them is a Duke. Only one of the Georgia Fiero Club members has a Duke and in my 15 years with the club, I can think of maybe 5 who did.
Consider changing out the fuel filter. It's cheap and after sitting for a while, you never know what condition the tank is in, especially if it sat with a dry or nearly empty tank. Fuel filters will allow some fuel to get through if enough demand is placed on it, even though they're badly clogged. Also, if the engine has backfired with you, the Dukes will sometimes blow the vacuum line for the MAP sensor off the bottom of the air filter housing. It's a hose that's not visible in a normal engine view so it can be overlooked. This can dramatically affect the fuel pressure regulator's ability to deliver enough fuel.
300 and 700 TBI regulator does NOT use vacuum like V6. MAP is only input to ECM. MAP vacuum is only use by MAP sensor.
But should check for vac leaks and bad EGR. Bad EGR or gasket can leak vacuum. Vac leaks can cause starting problems. Sometimes leaks can set ECM codes but most won't. Follow VECI label for most lines... brake booster line, cruise control. Booster line is long and can get rust thru or rubber w/ cracks. See my Cave, Vac Leaks
Originally posted by fierofool: I didn't know that (obviously). How is the pressure regulated?
Same as V6 and many others w/o vacuum/boost connection to "self adjust" range of fuel PSI. The 220, 300, and 700 TBI regulator is vented to normal air.
