2.8 in 88GT won't start after sitting
afn63537
12-18-2010, 12:37 AM
Car ran great when parked years ago. Can't get engine to fire up now at all.
Spark at the plugs.
Fuel tank, pump, lines, filter replaced
Fresh fuel in the rail and pressurized.
Fuses all tested good.
On injectors: I've seen posts where it's been said that if I take the mini connector off of one of the injectors that I should get 12v with key on and a pulsing 12v (blinking test light) on the other side (ECM side) while cranking. I've got 12v on both wires with key on, and test light (an LED) flickers slightly on both while cranking, but doesn't go out.
Anyone here able to shed some light on this for me? Greatly appreciated, and enjoying forum, too.
Spark at the plugs.
Fuel tank, pump, lines, filter replaced
Fresh fuel in the rail and pressurized.
Fuses all tested good.
On injectors: I've seen posts where it's been said that if I take the mini connector off of one of the injectors that I should get 12v with key on and a pulsing 12v (blinking test light) on the other side (ECM side) while cranking. I've got 12v on both wires with key on, and test light (an LED) flickers slightly on both while cranking, but doesn't go out.
Anyone here able to shed some light on this for me? Greatly appreciated, and enjoying forum, too.
jdl
12-18-2010, 10:59 AM
It has been sitting for years? Use a gage and ckeck fuel pressure. As far as unplugging injector and finding voltage on both wires, You would have to unplug all injectors that share the same ground, that voltage you see on the ground, may be coming from other injectors. Any applicable mil codes?
Scrapper
12-18-2010, 11:32 AM
on your plugs you say you have spark is it blue or yellow?
mcmalloy
12-18-2010, 01:10 PM
spray carb cleaner in the throttle body while someone cranks it over, if it wont start and run for a bit then its not a fuel problem
afn63537
12-18-2010, 04:59 PM
thanks all for your responses, and here's the latest:
jdl, fuel rail pressure is a solid 45psi and I've got the pump running continuously using an external power source with a manual switch
Scrapper, I used a spark plug to test for spark and could see the spark from inside the cabin, so I'd say it was strong.
mcmalloy, while cranking over engine, if I spray fuel into the air intake tube at the air cleaner, the car starts and runs until that fuel is exhausted, so it's definitely fuel, or lack of it, causing the no start condition
I disconnected the main harness to injectors 4 wire connector and tested the pins. The 2 on one side of the connector have 12v with key on, and the 2 on the other side show nothing with key on
While cranking the engine, the 2 pins that have 12v with key on fluctuate the LED test light I use, but the 2 on the other side still show nothing
The check engine light doesn't light with the key on. For that matter, no lights come on in the dash area, but the gauges seem to be working and the needles jump when the key is turned on. The tach also jumps while cranking, so it seems they are working.
I've got some ECMs from boneyards left over from working on my dad's 89 celebrity with the same engine in it. I'm thinking about swapping one out to see if that might be the problem, but I don't really remember if any of the ECMs were working when put into storage years ago. Would I be taking a chance on causing damage doing this, and should I swap out the PROM chip
jdl, fuel rail pressure is a solid 45psi and I've got the pump running continuously using an external power source with a manual switch
Scrapper, I used a spark plug to test for spark and could see the spark from inside the cabin, so I'd say it was strong.
mcmalloy, while cranking over engine, if I spray fuel into the air intake tube at the air cleaner, the car starts and runs until that fuel is exhausted, so it's definitely fuel, or lack of it, causing the no start condition
I disconnected the main harness to injectors 4 wire connector and tested the pins. The 2 on one side of the connector have 12v with key on, and the 2 on the other side show nothing with key on
While cranking the engine, the 2 pins that have 12v with key on fluctuate the LED test light I use, but the 2 on the other side still show nothing
The check engine light doesn't light with the key on. For that matter, no lights come on in the dash area, but the gauges seem to be working and the needles jump when the key is turned on. The tach also jumps while cranking, so it seems they are working.
I've got some ECMs from boneyards left over from working on my dad's 89 celebrity with the same engine in it. I'm thinking about swapping one out to see if that might be the problem, but I don't really remember if any of the ECMs were working when put into storage years ago. Would I be taking a chance on causing damage doing this, and should I swap out the PROM chip
afn63537
12-20-2010, 12:34 PM
Just got a set of NOIDs from autozone and tested at one of the injectors, and it pulsed when cranked over, so not sure where to turn now.
any ideas anybody? I wouldn't expect all the injectors to be clogged from sitting, and not looking forward to pulling the plenum.
Merry Christmas to all.
any ideas anybody? I wouldn't expect all the injectors to be clogged from sitting, and not looking forward to pulling the plenum.
Merry Christmas to all.
jdl
12-20-2010, 01:14 PM
At the four wire injector harness, With everything off, do an ohms test, between A & C, the test between B & D. Let us know the reading?
Scrapper
12-20-2010, 01:34 PM
did you look at air filter and hold it up outside in the light to see if you can see threw it? or maybe a mouse has got a nest in the filter housing . only other thing i'd check if cat coverter may be bad by setting that long? or a relay telling it not to get gas to injectors?
jdl
12-20-2010, 02:07 PM
As far as your fuel pump, you shouldn't have to use a jumper wire, to run. Even if you threw the computer out in the yard, the pump should still run, as long as you had oil pressure.
I've seen obd1 vehicles where the mil was burned out, I used a scanner that would showed live engine data.
I've seen obd1 vehicles where the mil was burned out, I used a scanner that would showed live engine data.
afn63537
12-21-2010, 02:29 AM
jdl,
should I disconnect the 4 wire harness and be testing the injector side? the wire colors there are
1)GREEN probably D in schematic
2)BLUE probably C in schematic
3)PINK probably A in schematic
4)PINK WITH BLACK TRACER probably B in schematic
I disconnected the 4 wire plug and with all power off, the tests went like this.
1 and 4 gave reading of 3.9 ohms between them that would be B and D for injectors 2,4,and 6
2 and 3 gave readings of 3.9 ohms between them that would be A and C for injectors 1,3,and 5
1 and 3 gave readings of open circuit between them
1 and 2 gave readings of open circuit between them
2 and 4 gave readings of open circuit between them
as far as the fuel pump was concerned, I made up a high pressure supply system with it's own reservoir, pump, lines, and manually controlled power supply to be able to take the place of the car's system for testing purposes
It does seem strange that none of the idiot lights work with the key on, including the mil, but since it fired up right away with the starting fluid and the NOID light was giving me a pulse, I didn't worry too much about the lights.
I used to have an old MAC 5000 for testing odb1 data, but didn't think it would give me anything to work with in diagnosing this no start condition.
should I disconnect the 4 wire harness and be testing the injector side? the wire colors there are
1)GREEN probably D in schematic
2)BLUE probably C in schematic
3)PINK probably A in schematic
4)PINK WITH BLACK TRACER probably B in schematic
I disconnected the 4 wire plug and with all power off, the tests went like this.
1 and 4 gave reading of 3.9 ohms between them that would be B and D for injectors 2,4,and 6
2 and 3 gave readings of 3.9 ohms between them that would be A and C for injectors 1,3,and 5
1 and 3 gave readings of open circuit between them
1 and 2 gave readings of open circuit between them
2 and 4 gave readings of open circuit between them
as far as the fuel pump was concerned, I made up a high pressure supply system with it's own reservoir, pump, lines, and manually controlled power supply to be able to take the place of the car's system for testing purposes
It does seem strange that none of the idiot lights work with the key on, including the mil, but since it fired up right away with the starting fluid and the NOID light was giving me a pulse, I didn't worry too much about the lights.
I used to have an old MAC 5000 for testing odb1 data, but didn't think it would give me anything to work with in diagnosing this no start condition.
afn63537
12-24-2010, 11:14 PM
A Merry Christmas to all, and many thanks for your help.
Scrapper
12-25-2010, 09:32 AM
i was going to wish every on a merry christmas and happy new year so i 2nd that with afn.
afn63537
01-07-2011, 04:07 PM
Happy New Year everybody!
haven't heard from anyone lately on this thread
does anyone know what the readings should have been on the injectors that I tested?
jdl suggested the following:
At the four wire injector harness, With everything off, do an ohms test, between A & C, the test between B & D. Let us know the reading?
both readings were 3.9 ohms, but I don't know if that's normal or not (see my 12-21-10 post)
the car runs as long as I keep putting propane into the intake,
the fuel is fresh,
the fuel rail holds 45 pounds steady during cranking,
and the noids I hooked up to in place of the injector blinked while cranking,
so it seems like the injectors are not firing or are plugged up somehow.
It just didn't make sense that they'd all plug up at the same time even though it had been sitting for a long time. I really didn't want to take off the plenum to pull them if something else might be causing the problem.
thanks
haven't heard from anyone lately on this thread
does anyone know what the readings should have been on the injectors that I tested?
jdl suggested the following:
At the four wire injector harness, With everything off, do an ohms test, between A & C, the test between B & D. Let us know the reading?
both readings were 3.9 ohms, but I don't know if that's normal or not (see my 12-21-10 post)
the car runs as long as I keep putting propane into the intake,
the fuel is fresh,
the fuel rail holds 45 pounds steady during cranking,
and the noids I hooked up to in place of the injector blinked while cranking,
so it seems like the injectors are not firing or are plugged up somehow.
It just didn't make sense that they'd all plug up at the same time even though it had been sitting for a long time. I really didn't want to take off the plenum to pull them if something else might be causing the problem.
thanks
Automotive Network, Inc., Copyright ©2025