I have 89 firbird 5.7 350 tpi. my injectors are reading 18 ohms on all of them how is this possible and could this be why i cant start the car until i pulse ground the lead "with an external ground wire" then it will allways start.

also if the car has not been touched in hours it will start the first time but as soon as you turn the motor off it will not start again.


have replaced. list........

computer, ingition module, pickup coil, spark is good, feul pump,
and many other things... coolant temp is normal during problem.

It was monitored with a tech 2.

thanks for any insights and help.

 

I believe 15 to 20 ohms is normal. But all mine on my'89 305 read 17 ohms- even the one that was staying open all the time!

 

If the resistance is too high you could have problems starting warm. I had 2 injectors in my beretta that when they would get hot my car would actually shut down. It wouldn't start again till the injectors cooled off.
I believe the correct resistance for 92 350 injectors is 10 ohms. Mine are at 15 ohms (accel) and when it gets warm the car starts a slight miss.

 

any ideas as to what it could be that makes it not start?

 

How is the battery and alternator?

 

Battery is great and its a 250 amp altinator... puts out 14.5 when it starts....

 

Does the motor crank freely and quickly when trying to start after it's been off (but is still warm)??

 

ok check this out....

Lets say i walk out and its cold....

engine starts runs perfect power is thier .... You would comment about how solid the motor runs and how responsive it is

Were talking perfection.... then you turn it off wether youve been running 30 seconds or 2 hours. the motor will not start it will turn over and over and over until you run the batter down

now everything is getting spark and all the basics ... but thier is one way it will allways start... all you have to do is ground the injectors by taping a wire on to the ground like 3 times a second while its starting and boom the motor starts firing and it starts.

Why do i have to do this to start and how can i fix it....

what is causeing me to have to supply ground to make it start...

No mechanic on the planet has been able to figure this out....

no amount of mony has brought this problem to an end....

i ask you ...... what in the world is going on?

 

Audio my friend,
It is your ignition coil....100% I had the same problem.
Well, maybe not 100%. But your problem is exactly and old one I had. The ignition coil was shot and was saturated not allowing enough power to the plugs. Now, since you are talking about grounding...check your ground wires from the block to the firewall and the main - lead from the battery to the block.

 

we replaced the pick up coil.... with a new one that we also tested in another vehicle...

the grounds are all good on the block....

anything else?

 

Maybe I'm wrong...but the pickup coil is with the distributor. I'm talking about the ignition coil...the one that sits on the passenger side area. The pickup coil is kinda built on the distributor..

 

It's time to get a shop manual and start running diagnostic trees. Yes, one freaking pin at a time. You've got a bad ground or a sticking relay somewhere. This is DEFINITELY electrical in nature. Nothing mechanical would cause this.

There are grounds and relays in places you can't even imagine on computer controlled EFI engines.

 

Just a guess but what does the TPS read when it won't start? If five volts, that's your problem right there. The ECM thinks you want "clear flood mode" and won't pulse the injectors. It's a shot at least.