I'm having an issue with a 91gt that I just got.

It's doing the no start.
Have checked the usual suspects
It's getting spark, passed the fuel pump jumper test,
I just can't get it to fire.
Having checked the Fuel injector post, I've found that when I jumper the lh relay that I still don't have juice at pin 18.

I've visually inspected the injectors, did the ign relay check to find about 1ohm less on slot 2 than on slot 5.

All the injectors and harnesses look in extremely good condition.
I'll have to remove the pan and jack it up tomorrow to check for the 02 sensor harness.

- A couple of oddities. - the PO cranked on it quite a while trying to get it started, it's seeming to leak oil/gas out at the dipstick base when cranking.
- I thought 91's would flash the engine mgmnt light with error codes if you turn on ignition and press your foot to the floor. This one won't
- LH is a relatively new rebuilt unit.
- I can't hear any clicking from the injectors though it sounds like theres a fan running pulling air into the temp sensor.
Worked fine one night then wouldn't start the next.

Any thoughts??
Thanks a bunch

 

Check for voltage at the fuel injectors with the LH relay jumpered 30 to 87.

 

During my no-start I got volts at the injectors, though the car wouldn't run. I then bought an injector noid light and saw that the voltage was not pulsing as it should. Testing with a multimeter will not show the pulsing that a noid light will show.

I bought this one. Designed to be universal, and works like a champ.

http://usatoolsinc.com/universalnoidlight.aspx

 

You now what would be cool? A multimeter with an injector test function. It could just be an LED built in to the case that pulses just as a noid light does. Or does one already exist?

 

I just emailed Fluke:

"Hi. I use a noid light to test fuel injectors. The noid light pulses to indicate that the injector circuit is pulsing as it should to open and close the fuel injector. I wonder if it would be possible to build an automotive multimeter with an injector test function like this built in? It could be as simple as an LED installed in the case of the meter that would pulse just as a noid light does when sensing the voltage pulses from the injector computer, and would reduce the tools needed for injection system testing by one.
Thanks."

 

Hate to ask but dose it have gas ? I thought I read about the fuel gage had to be set?

 

inspect the computer relay with the clear cover see if one or the other lights are illuminated its on the computer housing,

replace these relays with a known good one,
the horn relay will work,
do one at a time.

X ignition relay
XXII EZF
XXV LH
XXVI fuel pump, also replace the fuel pump fuse

also in your case since the engine has seen a lot of cranking pull relay V
and look at the bottom for the solder joints to be melted and smell it for burning,
if you find either indication then replace this relay as well so you wont get stranded with a non cranking engine.

Also pull the vacuum lines off of the 2 dampoers and fuel pressure regulator smell the hoses for fuel any fuel indication then this part is leaking.

For the oil leak at the dipstick,
remove the 10mm bolt that holds it to the timing cover,
then remove the tube see if there is an O ring on the end of the tube or inside the girdle,
the O ring should fit on the small diameter of the tube and the shoulder should fit flush with the girdle,
if the O ring is there then you may have a leaking front main seal,
or the tensioner boot requires investigation,
or tensioner gasket is leaking ,
refill the tensioner with STP use a visene bottle

 

Thanks Merlin
I checked the relays and found that my ignition cutoff relay wasn't in too tight. I now have juice at the lh 18 pin when the lh is jumpered.
I get power at the injectors but no pulse.
Should both wires be hot?
I attached a noid light to ground and it lit up, but didnt strobe when cranking.
Ground or LH?
cheers
bil

 

You install the noid leads into both sockets on the injector plug, then crank.

 

the fuel injector plug has 12V pos and is grounded by the computer to compete the circuit the noid should flash but,
, did you swap out each relay one at a time and try to start the engine, try holding it to the floor incase its flooded

 

Hi Guys
just an update.
Still no start
I checked all the relays.
The injectors get 12v but they don't seem to be grounding and firing.
a small bit of starting fluid fired it right up.

I'm sending the lh in for testing. We'll see what happens
bil

 

Does the fuel pump run when you crank the engine now ? If not check you haven't fitted a 53 relay into the kickdown slot by mistake. The rev counter should flicker when you crank if the LH is getting the required rpm signal on pin 1.

If fuel pump is energised when cranking check there isn't a short on one of the injector connectors - peel back the rubber boots on each one.

 

If the LH test good, verify the signal wire from the EZK to the LH.

Also if you havent done so already replace the CPS (reference sensor).