a friend of mine has a shop and he called me last night with a little problem, the car came in for the oil to be changed and now the car doesnt run, he's been throwing parts at the car (new computer, cap,rotor,plugs,wires) he said hes not getting any codes but he has to spray starting fluid into the throttle body to get it running, the car will not fire if you dont spray the ether, my buddy is out of state so i cannot go to check it out any of you guys have any idea how i can help my buddy out, thanks.

 

basics man, does it have a good spark? A weak one would ignite that crap hes spraying in their but prob not all the gas the tpi wants. Once the spark is good, makes sure theres fuel in the rails via a pressure guage on the shrader valve.

 

he did that he said that it has plenty of pressure at the rail

 

does the car try to start or ? . check the electronic spark module that controls it.it should be up by the firewal on drivers side under the hood.

 

the car cranks over just like it does normally just doesnt't start, it will start when you spray the starting fluid into the throttle body, we changed the computer, spark plugs, wires, cap, rotor, basic tune-up parts.

 

what baout the black box type thing under the dist cap? mine crapped out on me, engine turned over just didnt start

 

i just dont get how the car would fire up without the starting fluid, it got plenty of spark and there is fuel pressure at the rail

 

what about the altenater or the condition of battery

 

Maybe get a noid light and test to mke sure the injectors are firing?

Injector Fuse?

If it will run with the fluid, it has spark, but no fuel.

 

car has a new alternator and a new optima battery

 

Maybe your friend needs to find a new line of work, if he can't fix cars he's in the wrong business.

 

had that same problem with my 87 GTA - turned out to be the fuel pump. I was getting pressure at the rail, but not enough to get the car cranked up.

"Plenty of pressure at the rail" isn't what the TPI cars require. Gotta have it within their tolerances or it won't work

 

i dont know its tough not physically being there hes trying to explain all of this on the phone, now hes saying that the guy is taking him to small claims court so i dont know anymore, i think he got it all figured out but him and the customer had a dispute over the parts.

 

A no crank problem from an oil change? Maybe somehow he disconnected a wire or two from the oil pressure switch when replacing the filter. On that year t/a they had a cigar shaped switch thats over the oil filter, and if the computer doesnt see oil pressure that switch shuts down the fuel pump as a safety percaution from engine damage, or maybe he didnt put any oil in it when he did the oil change?

 

Finally, I was just going to mention that. If the car ran before it came in, but wouldn't run afterwords then the Oil Pressure sending unit is the first thing I'd check. If its connected, but still wont' start I'd replace it. Its a cheap enough part.

 

It would be a spiffy design if it really worked that way, but it doesn't.

The ECM doesn't monitor oil pressure on any year 3rd gen. Period. Try to dig up a schematic that proves me wrong if you don't believe it. The PCM doesn't even monitor oil pressure on 4th gens all the way through 2002 models.

On every TPI schematic I've seen, there are at most two parallel paths that can close the fuel pump circuit:

1.) ECM-managed relay, which is closed for 2sec on initial key-on and then closed again when the ECM sees distributor reference pulses.

2.) Oil pressure switch: closes at designed oil pressure and feeds 12VDC to the pump circuit independent of the ECM-managed relay.

The ECM will keep the fuel pump powered as long as the engine continues spinning the distributor, right up until it throws a rod or otherwise stops spinning.

 

Im not saying i disagree at all. I thought i read somewhere that thats what that design oil pressure switch could do and thats why the fuel pump wire (tan/white) is hooked up to that switch.