beach_house

injectors not pulsating.car sat for bout 2years. went just bout all way through it. got spark,fuel to rail.ect...but my injectors have power just no pulse to run on its own.ive read alot and everyone says change this and that. ive also read that lots of that didnt need replacing. car ran fine. parked it 2 years ago and no start.grrrrr..any ideas.this was the site to go to eveyone said so i hoping this is my final answer.well any ways its a 1989 formula 350TPI. some one answer my prayers.thanx,dave

irocuroc

you could have a shorted multec injector that will shut down the ecu.. get a ohm meter and check each injector. They should be at 16ohms.. if any are below 10 they are no good.. Do the ohm check and report back

puddingmmmmmmmm

iTrader: (5)

Not sure if this will apply to your situation, my injectors acted really dumb when one of the fuses blew. Double check them just in case, because one of mine were blown and I was lost for about a week, not even thinking about checking the fuses.

vetteoz

iTrader: (13)

If the fuses are blown he won't have 12V at the injector

If you have VATS that takes out the injector pulse and starter.When VATS module faulty possible to have crank but no injector pulse

John 89 Formula

have your ignition module tested, a bad one will not fire the injectors.

emmanuel33v

Check your fuel pump relay bro.....In had the same exact thing going on with my car and it was my fuel pump relay that wasnt working... my car had fuel 45 psi when i checked i had spark everything was good and it would only start on starting fluid...check you FUEL PUMP RELAY....hope this helps

Zepher

iTrader: (1)

Bad fuel pump relay won't keep the car from starting.
The oil pressure switch will run the fuel pump. Module and ECM control the injectors, Module fires the injectors initially until the motor hits 300rpm then the ECM takes over.

alltpi

iTrader: (1)

Hi I'm having the same problem with my car now sat for an year now only starts on starting fluid no injector pulse. please help

soxbaseball

the same thing happend to me. I replaced the fuel pump, fuel sending unit, and all my fuses. and all it was was one wire had been chewed into. theres an inline fuse with a wire that runs beside the motor and underneth the brake booster. that was my problem so i would chase all your wires and make sure they are all still intack hope this helps

vetteoz

iTrader: (13)

As noted above.
Fuel pressure ?
Check injector fuses ; check resistance on injectors.
One bad injector will shut the whole bank down
Get a noid light and see if you have pulse at injectors

alltpi

iTrader: (1)

fuel pressure is A ok, all injectors work with the car running all of them ohm out great, relays are good ignition module tested good but might change it any way....thats the last thing to think of ecm is good chip good I might replace all those fusible links thats on the starter with regular fuse holders......

vetteoz

iTrader: (13)

Confused
How does the car run with no injector pulse? Did you fix something ?

John 89 Formula

Check all the connectors around the distributor, make sure they are all seated properly and in the right place. Another member here had the same problem, it turned out the plug for the module was connected to the iat sensor. (the connectors are the same.)

alltpi

iTrader: (1)

FIXED IT, now starts all the time on a dime. it was the pick up coil inside the dizzy, good thing I got a couple extra distributors laying around I changed everything almost I have a gang of extra parts laying around, even if the ignition module test good it has to get a signal from the pick up coil to fire the injectors, the computer will do the rest after it gets the signal, The reason I missed this is because I put a so called new msd distributor in when I put the motor in so I never intended to look at the dizzy as the problem, now I know why they said to alwways use GM products this set me back almost 2 weeks for a 5 minute fix as soon as I dropped it in it fire right up I really hopes this helps out someone else.....

red92xblue

Thanks

alltpi

iTrader: (1)

almost red92 the computer didn't know the car was trying to start cause the signal from the pick up wasn't there at all and it kept me thinking the module was bad, untill I went on another website, Ok so let me clear this up when you crank the car the pick up has to tell the module the engine is turning to fire the injectors, after the computer sees the signal it will then pulse the injectors to start the car then after that the computer controls the rest of the car. the computer WILL NOT PULSE THE INJECTORS UNTILL IT SEES AT LEAST 300 RPM'S and the starter can only spin the motor about 150 rpm's, That's why our cars will start on starting fluid and run just fine cause the computer didn't pulse the injectors and you got the motor sinning fast enough for the computer take control

red92xblue

it.

vetteoz

iTrader: (13)

The way that has been written in the L98 start up sequence and way it has been described over the years is
The ECM needs to see 4psi oil pressure and the dist reference signal before it will pulse the injectors.
ECM " sees " the OP by being connected to the OP switch ( pin A20; "Fuel Pump signal" on '727 ) which closes @ 4 psi to run the fuel pump .

In any case highly unlikely that is your problem ( unless your OP switch is bad ) because engine will achieve 4psi while cranking and run the pump .This was the factory backup should the pump relay fail; allows engine to start ; albeit with longer cranking

red92xblue

Thank you

red92xblue

Update

vetteoz

iTrader: (13)

Not unusual problem.
VATS has two parts; starter disable and injector disable.
It is possible, as you have found out for the injector part to fail on it's own. Many assume that if engine cranks then VATS must be working correctly

red92xblue

Corvette.

fred b

Thanks guys I have the same problem injectors not pulsating, I wll test everything ya"ll did cause I was thinking aout going to card if I did"nt get any results.

red92xblue

luck.

fred b

Guys I can"t find the wire to disarm the vats on my 86 camaro. I took the motor out of a 89 Iroc TPI and put it in my 86 camaro 2.8 multiport. I changedthe steering column, new computer, new distributor, new module, newfuel pump relay, The car chranked ne time by the key and no more. i realized that the fuel pump never came on. What do I need to do next, should I put the original steeing column back in and try that. Please help

John 89 Formula

your 86 doesn't have vats, at least not from the factory, if your using the stock chip from the 89 it will never start 'cause the 89 chip has vats. it's looking for a signal from a vats module that you don't have. you need to use a chip from a car that does not have vats, or get a custom chip with vats disabled.

Also check the fuse by the battery, it supplies power to the fuel pump and ecm.

camaroz28chic

Ok i know this has been asked over and over again.. but i have a 95 camaro with a lt1.. it has sat for two years.. we got it started on starting fluid, runs but wont stay running.. fuel pressure off the rail is good.. what should we try next? or what could it possibly be.. dont want to go spending money that we dont need to.. if its something stupid.. thanks

utilityguy2

iTrader: (1)

are the injectors firing? get a set of noid lights to check or use multimeter.

camaroz28chic

yes they are.. we checked that today after reading this thread

melicious1

I'm a noob, I'm having same kinda problem, just bought a 90 IROC thats been sitting for 5 years.Dropped in a new battery, and all the instrument lights work , headlights blinkers etc. Turn key, and does not crank motor, I also don't hear fuel pump kick on, but if I poke starter it will crank over, and if I spray brake cleaner in inj. it will start up momentarily. There is juice at the relay, orange wire but that's about it. Any help would be greatly appreciated. Thanks, Ima old school naturally aspirated kinda old fool .

thesparkey

guys i am having the similar problem, i have a 1989 350 ttops, well my question would be if VATS has a problem and takes out the pulsating injector feature... IS IT POSSIBLE TO CRANK OVER WHEN I SPRAY STARTING FLUID IN THE INTAKE? because that is the way i am troubleshooting it and it does start with starting fluid being sprayed....

Tuned Performance

iTrader: (92)

Since it will run off starting fluid you probably don't have a icm issue. You might unplug all the injector connectors and check for pulse with a noid light. A shorted injector can cause the ecm not to pulse the injectors. Have you checked for ecm codes code 46 vats would also cause no injector pulse.

thesparkey

negative on vats code ... i currentoly have no trouble codes.... so i ohmed out injectors and here are my results : Injector 1- 13.6ohms , 2- 8.6ohms , 3- 8.1ohms , 4- 15.0ohms, 5- 16.1ohms, 6- 18.1ohms, 7-5.5ohms, 8- 12.3ohms....these reading were taken engine cold...... now heres what ive replaced in my car: Maf, Ecm, Fuel pump, checked all relays and fuses:good, thing i havent checked : Iac valve, Pick up coil,

thesparkey

engine starts when it wants to while pressing down throttle all the way.... now it will idle horribly and the funny part is if i disconnect injector #7 witch ohms out at 5.5ohms idle seems better, high at about 1500rpm but smoother accel, maybe injectors bad? its the most expensive last resort fix but i think that might be it? if so if i had 2 or 3 bad injectors would it cause my engine not wanting to start?

utilityguy2

iTrader: (1)

Most of your injectors are bad. should be above 15 ohms (if I remember correctly) and all the same +or- a few tenths.

Tuned Performance

iTrader: (92)

give south bay injectors a call.

http://www.southbayfuelinjectors.com...7&product=1502

thesparkey

thanks guys i will ...... so you think the issue im having: rough terrible idle, stall without foot on gas on stop signs, make sense to bad injectors? im getting 40 psi so thats good.. the thing i were thinking before injector were bad iac, pickup coild or even a vacuum leak i dont know about but vacuum looks good to me unless i have my EGR that dosent work and leaking there...

thesparkey

WOW YOU JUST SAVED ME ALOT OF MONEY THANKS BROTHA....


so i suggest you recommend ???

Thirdgencustom

iTrader: (5)

http://www.southbayfuelinjectors.com...7&product=1502

My car was running bad not wont run at all ,Enjectors not opening,so i check vats,

southbay08

I am sorry that you evidently had a "bad experience" with us. I truely do not recall being rude to any customer that we have ever dealt with as that is not good business. If you thought or think that you have a problem with our injectors, we will be more than happy to check them for you. Most people on this forum that know us, will agree that we will do anything that we can to help our customers.

Tuned Performance

iTrader: (92)

They are great , Highly recomend

Thirdgencustom

iTrader: (5)

I pm what happend,

Thirdgencustom

iTrader: (5)

Beside that problem i pmed about,everything was great fast shipping. great price.would use again!!!

southbay08

Thank you

Thirdgencustom

iTrader: (5)

Have to unplug a injector to get to run,If plug back in car dies?Bad injector?

Tuned Performance

iTrader: (92)

Check the resistance of the injectors when warm if you can if not than cold. I. Don't believe the Bosch 3's have the same issues as the multi techs fuel cooled coils that short out. This could be a faulty injector driver in the ecm.

Thirdgencustom

iTrader: (5)

Was running real bad( not getting enough gas)Then it stopped getting gas all together.Now i unplug the first injector on the drivers side.( Front of motor)
To run,I check res, ty

jhainer

With my 91 that sat for 5 years. had the same issue but only on one bank. first thing to check is fuses so i did well after 3 days of fighting with it and new computer later. come to find out the good fuse i had wasn't good i first checked the fuses and if i remember the passenger bank wouldn't fire. i pulledoutthe fuses and swapped then and then the drivers bank wouldn't fire. funny part of it was the fuse looked ok I kept it because it was strange to this day i would say that fuse is good.

southbay08

I have never seen a Bosch lll injector with a coil issue

OldManZ

Same thing here. Just bought an 89 Formula 350 that has been sitting for a few years. Determined fuel pump was bad and changed that out tonight along with nasty fuel filter. Car will start on ether but will not run. It was late and I wanted to get home but a friend quickly did a test with his power probe and he said we had power to injectors but they were not back feeding a ground?

Same friend drives a 85 vette with a built 400TPI and is a 15 year mechanic. He is the local TPI guru around here so hopefuly we will get to the bottom of this in the next few days and I will post our finds.