clutterhead
Newbie
Thats a good idea. I'll start there and update. I came across an interesting thread where someone had somewhat of the same issue I had. The response he got from a few people was that they also have that issue, but it's because of the ethanol in gasoline today. That the TBIs weren't designed to run on the concentration in modern fuel. Seems plausible, but I think I may be onto something that's showing it might just be slightly dirty injectors."I" would dump a bottle or two of Chevron Techron Complete Fuel System Cleaner in the tank, and buy only Top Tier fuel. See if the injectors clean themselves with some added detergent in the gasoline.
I know a lot of people are quick to dismiss the injectors being at fault saying they "almost never go bad", but that doesn't mean they don't get a bit dirty. Especially with the ethanol in fuel today. I know a lot of people forget that tiny circular screen on the side of those injectors when rebuilding the TB on these engines. I remember mine being clogged with that "ethanol film" that gets left over when the fuel evaporates. Maybe, maybe not.
Yeah I've heard the same. I might try some of the old tricks to bump it. I made an adjustable one at one point on another car. Might just try the quarter stacking for this one. Those aftermarket springs are priced ridiculously. I've seen a thread where someone compared various springs so I might do that later on and look for some mcmaster springs.True on a system where the fuel pressure regulator is vacuum-regulated. Not true on TBI where the fuel pressure regulator has no vacuum signal.
But 7 psi is low. Spec is 9--13, and "everyone" seems to think the higher-end of that spec is better.
No load is around 12.6VWhat is no-load battery voltage?
Now that I think about it, I did do a voltage drop across the contacts and there was none, so I concluded that the drop must be somewhere in the harness from the relay to the first connector. I sort of followed where it went into the main engine harness and concluded I was not about to tear into that. Mainly because I get charging voltage when it runs.Or swap relays. I get extras from the Treasure Yard.
A voltage-drop test with the relay engaged would tell that tale, too. Excess voltage drop = failing relay contacts. But that assumes that the battery voltage is sufficient.
It's just a weird scenario seeing that it gets full voltage when the car runs. Made me wonder if that was some sort of "priming voltage" the computer sends out on KOEO, but I didn't read into the theory that much to see if something like that exists. Never heard anything like that mentioned before though. The wiring diagram to the relay doesn't suggest anything like that either. The other wires are "ECM sense" and so on. I assume it's just that. The scan tool has a PID for fuel pressure voltage so I figure that is where that PID data is measured at. The likely scenario is there's resistance in the wire that is overcome when a higher voltage is present. Checked the ground at the connector and it was good. No evidence of overheated wires/connectors leading all the way to the pump. I guess I could do a current draw, but I'm erring on the side of leave it alone
I felt I should too. Eventually I'll get it back on.That's gotta change.
Put a brass tee in the block, route the OEM switch and wire harness to one outlet of the tee, put the aftermarket pressure gauge into the other outlet of the tee. Simple, easy, cheap.