First of all this is my first post so apologies in advance! I have read many posts/articles relating to the fuel injection system on the 85 and these have been extremely helpful, but I am still missing something, and I must admit this is my first attempt at serious car repairs. When I purchased this car it had not run for three years and the previous owner had stored the car with no gas in the system. The car also has major electrical issues, but that is for another post.
Reading the forums got me in touch with the fuelinjectorconnection.com. Cannot remember the guy I talked to, I think the owner, very helpful, and said if the car sat for three years without gas that the fuel rail O rings and injectors O rings probably failed. So I installed rebuilt injectors and new O rings, and gaskets.
The problem:
After replacing the fuel pump, hanger, and more (see below) the first time I turned the key to the “on” position with a fuel pressure gauge attached within the two second interval the pressure went up to 40+ lbs and then suddenly dropped to zero. On subsequent tests the pressure never goes up and you can actually hear the sound of gas trying to fill the rails. The sound is loudest near the fuel pressure regulator. I used a mechanic’s stethoscope and could hear sound going to the cold start valve. I probably shouldn’t have but since I didn’t see gas squirting out, and didn’t smell any gas, I had my helper crank the engine and after about 20 seconds the car did start, and seemed to run fine. I shut it down after only two minutes still worried about the fuel pressure problem. I pulled the plenum and removed the vacuum hose off the fuel regulator and no gas was coming out, and there is no smell of gas during the 2 second ignition on phase. I visually inspected all the O ring connection points on the rails and fuel injectors and found no visible signs of a leak and again no smell of gas. So after all these steps to hear the sound of gas gushing through the rails, no sign of leakage and no smell of gas, do you think it might be a bad cold start valve stuck open? If so what would be the easiest way to test? Is there a cap that can be put on the end of fuel rail where the cold start line connects? Here in Arizona I am not to worried about cold weather starting.
The things I’ve done so far
When I got the car I wasn’t sure at all what the starting problem was so I used Starter fluid to determine if the problem was electrical or fuel related. It started immediately and ran for about 10 seconds.
Replaced fuel pump and hanger, and cleaned the tank surface where is meets the gasket. Purchased a kit from Racetronix which included a Walbro 180L/Hr Pump. The gas tank had three broken bolts protruding from the tank surface, which someone had left in the tank causing the the hanger mounting flange to badly bend and not seat on the fuel tank correctly. Some sort of goop was used to seal the bumpy mess.

• Replaced fuel filter and O rings.
• Replaced the fuel injectors with rebuilt set of 8 Bosch Design III 24 lbs. Replaced all O rings, and all related gaskets.
• Replaced fuel pressure regulator with a rebuild kit
• Replaced EGR valve, something caused the vacuum lines from the EGR valve to melt. More precisely the there was a two inch section where one side of the pipe skinned off.
• Replaced the spark plugs
• Replaced the spark plug wiring. At least one of the plug wires had a burn all the way through the insulation.
• Replaced distributor cap and rotor

 

yes I believe you can remove the cold start and check your oil for fuel

 

are you doing this testing with the engine cold ?
if so the cold start will be activated and try to prime the engine.
the fuel pump runs for 2 seconds when ignition is on, then will stop if it doesnt detect the engine turning.

if the engine is running fine and holds fuel pressure when warm you may not have a problem to be concerned about.

 

The cold start injector only works while the engine is cranking. It could still be leaking, though. I have not heard of anybody finding a leaky cold start injector.

"Cold" to you is a lot different than cold as far as the engine is concerned. You may consider 110° "hot", but that's cold to the engine, which normally operates at twice that temperature.

The fuel system is a recirculating type. The fuel pressure regulator bypasses excess fuel back to the tank, so fuel is indeed flowing through the rails all the time the fuel pump is operating.

The fuel pressure suddenly dropping to zero sounds like a bad connection to the fuel rail, since obviously there must have been fuel pressure if the engine was running. The fuel pressure gauge must depress the Schrader valve to read the fuel pressure. Some fuel pressure gauges don't do that very well, so that could be your problem.

 

Years ago, on my 88 Irocz , the CSI was leaking. It would start up fine when cold, but when the car got hot, it would crank for a few seconds before firing up.

I tried to troubleshoot that issue for a while before I accidently solved it.
I installed a Superram that had no provision for a CSI.
I capped the CSI off and next thing you know, the car starts up right away even when hot.

I made no changes to the Tune. I really feel the CSI is not needed.

Vic

 

Thanks for all the advice. So Cliff are you suggesting the cold start valve is on anytime the car has cooled ie. sat overnight?
I am going to borrow another fuel pressure gauge, and repeat the tests. I forgot to monitor the gauge after the engine was running, so I will also check that. Any ideas on capping off the cold start valve? Is there a cap that can be screwed into the rail where the cold start valve connects? or is this sort of thing a machine shop deal? Since this is still a theory I don't want to permanently change things until I figure this out.

 

The cold start thermo switch will activate the cold start injector if the coolant is lower than 95°.

You replace the cold start fuel line with a plug in the end of the fuel rail. I don't know what size is needed.

 

Bingo Why the gauge worked the first time and not all the other times...
I went the Oreilly's Auto Parts and borrowed their fuel gauge, found pressure but still had a leak. Started car and with it running found a very small leak caused by a damaged O ring where the cold start valve meets the fuel rail.
Thanks to all this is the first time this car has run in 3+ years
Now on the wiring problems...