View Full Version : Only runs on ether--HELP

10-13-2005, 06:07 PM
Here is my situation. After having electrical problems fixed, starter wiring ect. I followed all the info I could find about testing modules and things I ended up swapping my original ecm, coils and module back in. I have spark, fuel pressure at the rail, and injector pulse at #1 injector(noid light). I am concerned about the fuel pressure, It keeps on priming the rail almost every time after checking something, so it pumps up to over 80lbs is this OK.
It was backingfiring so I rechecked cam sensor. I have been using a shot of ether just to kick it. It will fire up and use up the fuel and die. I rechecked with noid light and ether and when it runs the light flashes faster as it should.
I am getting concerned about some of this cranking and firing for a short time.
This is a brand new engine and I am VERY worried about wiping the cam. I have not let it idle ,but I also cannot keep it running. The plug I checked was not wet with fuel, and I cannot smell any. When it does fire it sound great!!
There are very few old parts in this, rods, crank block.
Injectors are new Maybe run 15 minutes before teardown. Fresh gas.
I did try running the accufab adjustment screw up and down. It only increased my static press. at the rail. So now I also lost my orginal setting on that. Any ideas on the number of turns to start??
I do have all the goodies in place, and I am very close right now. But I know I must not be getting the fuel INTO the cyl. How do I check ??
I have not been able to find an answer in the archives as of yet.
Mart Urbanski

10-13-2005, 11:39 PM
I wonder if your fuel pump relay is staying closed. Do you lose pressure after it starts? The priming source to kick the relay is different than the sustaining source, I think...

85 ttypewh1
10-14-2005, 09:39 AM
Do you have a fuel psi gauge at the rail. If so turn the key on 2 or 3 times and leave it on. Now go to the fuel adj regulator on the rail and watch the fuel psi gauge and turn the adjusting screw to get the psi to about 50 then lock the adjusting screw down and leave it. Then try and start the car. when you changed the ecm did you put the 2 correct chips in it.

10-14-2005, 07:11 PM
Yes I do have a gauge, got it from one of our vendors. I the FP reg is a accufab with minimal time on it. Seems odd that it would go bad from sitting. maybe I'll open it up and take a look. I know the rails hold pressure for a long time. I'll have to bleed some pressure then reset it. You know how it goes, you mess with something and try it again, thats when I noticed it was pumping up. It also made sense to me that AFTER it started it would be the time to set it. And I do have both chips in it correct. My original ECM had the ***504 chip. I am out on wether the postons chip is any good. I was planning on running the 87 ECM with a brand new turbotweak chip in it untill it would not fire at all with the (good used coil and module)
This is also the first time I ran across the info about to much pressure! Good stuff. Any parts and upgrades I have done were with info gathered from these groups and I purchased the best I could afford at the time. Upgrade not replace!.
I will not have time to play with it untill late sat. but I'll keep you guys posted!

Q? can I run the new chip in an 84 ECM?

10-14-2005, 08:17 PM
Some of you GN experts might be able to expound on this, or even correct me--but if it's not running at all (except for the ether) then it sounds to me like it's not getting any fuel at all. I doubt that the regulator could cause that problem, unless it's just plain closed off and isn't letting ANY gas through. Even if the fuel pressure is really low it should at least run (albeit badly).

Sure, if the fuel pump is weak or the pressure setting is wrong it will run poorly...but not running at all? I don't think any gas is getting through at all.

I suspect an electrical problem.

Are you sure you have fuel pressure while you're trying to start/run? Are you sure the injectors are firing? Maybe a wire somewhere in the ECM/fuel injection harness is improperly connected? Are you sure you have a good chip/ECU/etc?

10-14-2005, 09:07 PM
I do have spark. (shorted plug out) I do have a good fuel pump, I used it to drain old fuel, i have press to gauge that is mounted to the fitting on fuel rail.
I purchased a new noid light , it flashes on the two injectors plugs I tried. It's a new Caspers harness. It also rises when engine rpm increases.
So wouldn't that make all the systems somewhat OK? The chip is a question, I'll try the 110 chip in my tool box just to see what happens.
My next thing I was going to do was remove rail and injectors,plug it in and roll er' over!!
That I think will tell a ton! Might be messy but maybe I'll learn some thing.

10-16-2005, 11:41 AM
Started going thru my fuel system today SUN. And I was wondering why this looks backwards to me? The fuel line goes from fuel pump to fuel filter THEN to pass side of fuel rail and OUT thru the FP reg. I don't see why it would flow that direction, but the lines look like they only fit one way. I opened up the ACCUFAB and it looks brand new as it should. I just think that the fuel should get filtered first, pass through the reg to get adjusted pressure then return back to the tank!
Have I been smelling to many fumes??

10-16-2005, 02:15 PM
How about a plugged return line?? I cannot blow air thru from the lower fitting of the fuel filter. I'm not sure which one it is from the tank forward, But I do know which one is the feed(it has lots of fuel) I unhooked the other two at the tank.I think I hear air leaking when I add air to the line from the charcoal canister. It's hard to hear by my self. Is there a check valve inline?
I lose sight of this line when it enters the frame, but I cannot see any pinch points up to that point. Will this line be hard to replace? I went to -6an lines on the trans because they were a PITA so I quit trying and put in the braided lines.
I did have the screw on the FP Reg backed all the way out, before I shorted out the fuel Pump for a second and it still ran up to 80#.

10-17-2005, 01:44 AM
I did have the screw on the FP Reg backed all the way out, before I shorted out the fuel Pump for a second and it still ran up to 80#.
That is odd. Don't think it would go that high backed out.

Is it possible that the lines are not all going to the correct places?

There is a supply, return, and vent line all coming from the tank. Actually, right from the pump hanger assembly. The supply line comes from the pump, the return goes into the tank/hanger unit, and the vent is just from the top of the hanger. Three lines run the length of the car. They could be messed up in several different places.

I'd be curious what the system was doing if you applied (FUSED!) power to the test connector under the hood. I know the 84/85 cars have thes, just like the 86/87 cars. Might give you a chance to listen around the system to see/hear what is hapening, and where.

10-17-2005, 08:44 AM
I'm just thinking out loud here:

...if the return line were plugged, then I would think that you would still be getting fuel. Of course, the pressure might well be wrong, but my guess is that it would still at least run.

I would see if you can do some kind of test to verify that you are getting not just the proper pressure, but flow as well. I know that for many other cars there is a procedure that works something like this:

with the engine OFF, loosen a fuel line at the rail (I belive it is the return line) and direct it into a suitable container. Turn the ignition "on" but don't start the car. The fuel pump should come on for a few seconds. During that time you should have a certain amount of fuel delivered into the container. I don't know what the correct amount is, but I have seen this procedure documented in Hayne's and Chiltons books for various cars, and they usually state how much gas you should have collected.

If you are getting the proper amount of fuel volume/pressure, then you can look towards something outside of the fuel pump, etc.

10-17-2005, 08:18 PM
if the return line were plugged, then I would think that you would still be getting fuel. Of course, the pressure might well be wrong, but my guess is that it would still at least run.
Some injectors will 'lock up' when the pressure gets too high. The MSD/Rochester injectors are notorious for this. (50#, 55#, etc.)

What type of injectors are in the car?

10-18-2005, 06:19 PM
The pump works just fine. I did jump that lead when I drained the tank the other day. I have some kind of blockage in the return line . I'm going out the look at it right now. I had to cool down a bit after trying to remove some of the line clamps! If I ever find that ninth grade engineer that designed the clamp locations &*^^^%#^%4. I would be fired if I ever designed something that bad!

10-20-2005, 12:15 PM
I agree that your lines may be reversed. It should run from the pump, through the filter, into the rail on the passenger side, through the regulator and back to the tank. If the supply and return are reversed, your pump is pumping to the output of the regultor, which would be closed since the rail has no pressure, and you would read the max pump pressure of 80 psi regardless of how the regulator is set. I would trace them out, correct them, and then fine tune the pressure, hopefully, it will be that simple, good luck.

10-22-2005, 08:08 AM
I FOUND IT! It's the return hose assembly at the front of car. Something is plugging it TIGHT at the crimp fitting. I cannot get a wire through there YET. I filled it with gunk rust eater? and letting it soak. It would be a easy fix just to buy one but I have a hard time justtifying 90 bucks for the piece. There is a site I found if I cannot unclog it. Lingenfelders has a repair kit, at least I think I can fix it with this