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View Full Version : No start. Need Help!


dverdu
08-30-2004, 09:58 PM
Hi all,
I have an 87 GN that wont start. Here's what I checked for so far.

* Spark at coil pack (good)

* Fuel Injectors pulsing (good)

* Fuel Pressure (good -40psi)

* Rechecked Cam sensor position (good)

* Disconnected downpipe at turbo (thinking possible clogged exhaust)

* Compression test on all cyclinders with throttle in wide open position and all spark plugs removed(70 psi on all cyclinders)

*Cleaned and regapped spark plugs and blew compressed air into cyclinders (thinking that it was flooded). Also, tried to start in clear flood mode.

*Checked all sensor and ignition signals using Vantage Multimeter (Good)

At this point I'm thinking jumped timing chaining or carbon build up in cylinders but wanted to see what you guys think. I don't wan't to go in this direction if not needed. Is there any cleaner I can spray in the cylinders that might losen up carbon deposits? Thanks for any suggestions.

Keller
09-01-2004, 01:25 AM
I once had a pair on a coil pack go bad, drove many miles home with it that way, and the car barely ran even after replacing it. Turns out the plugs were so fouled, they would barely fire. Replaced, and no furhter problem.

Why do you suspect major carbon desposits?

Do you have a scan tool? Spare ECM?

dverdu
09-01-2004, 03:28 PM
I have tried another ECM with no results. The carbon deposit theory came up because I am running out of ideas why the GN won't start. What do you guys think the likelyhood of a jumped timing chain is and is there any way to test for it without removing the timing chain cover?

PIreland
09-01-2004, 10:14 PM
How is the crankshaft sensor? Are you getting any ECM codes?

dverdu
09-02-2004, 05:35 PM
Actually, I replaced the crank sensor and checked for the actual raw signal going into the ignition module using a snap on vantage meter(good signal). Also, I cleaned the ring gear that passes through the sensor. I'm not getting any codes. I checked pretty much everthing that could make it not start. Any help would be appreciated.

PIreland
09-02-2004, 07:25 PM
Are there any hidden switches in any of the circuits? Were there any in the past? Maybe a switch is bad or a splice is bad. Also, is the orange wire in good shape? I presume it is connected.
What was done to the car between the last time it was running and now?
I assume the car won't fire at all?

dverdu
09-03-2004, 08:11 AM
The car was running fine then it started missing and eventually just died out and won't start back up. That's the frustrating part becuase it was running fine. There are no circuits in between that would cause it not to start.

Keller
09-03-2004, 02:17 PM
It is starting to sound like the ignition module (below the coil pack). How old is this unit? Can you borrow another? Can you borrow a Casper's ignition system tester or do you have one?

When an intermittent problem becomes a fatal one, it sounds electrical to me...

84T-typeMike
09-08-2004, 11:40 AM
70 PSI on ALL cylinders?That sounds way,way low?I thought mine was low @ 130/134 pounds on ALL cylinders.If you get spark at the plug and your fuel pressure is good.I think it might be a jumped timing chain as the equal range of 70 pounds on all cylinders might mean valves are opening at wrong time.I would'nt think all cylinders(rings and things)would All go that bad at same time.Look at the timing chain.Just a guess!

dverdu
09-17-2004, 12:25 AM
Well, finally solved the no start. Turns out it was the adjustment of the cam sensor in combination with an intermittent ignition module. When adjusting the cam sensor I did not make sure the #1 cylinder was on TDC of the compression stroke, rather ir was on TDC of the exhaust stroke. Opps! Could happen to anybody right? Glad the GN is running now though. Sometimes it's just a process of elimination. Thanks to all for the suggestions. :)