Alright, while I admit to being woefully ignorant as to what a supporting vendor is/does I have to say the fuel pressure gauge is way out of left field. If you read the thread it clearly indicates an ignition/relay issue, and in the five years its been up no one else has mentioned the need for a fuel pressure gauge. I responded to the post because it was the quick turn of the key that got my wheels spinning again. Im guessing that changing out the EFI relay is going to fix the issue, but was hopping for some info from the person with the exact same issue that I seem to have. Icwizard I appreciate the advice and am not saying its self serving or malicious, just not very good for my particular situation.
Riddle me this.
- Thread starter RMutt2017
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Your still responding like you already know the answer. Keep up at that rate and few will bother to lend a hand. OFTEN threads end w/ no resolution. It’s what it is. IF this is your attempt at a conclusion then woohoo to you and by all means let the thread know if the relay fixes the issue.
I'm pretty sure that @lcwizard was simply trying to help rule things out by crossing things off the list by process of elimination. I don't think saying "the gauge eliminates one of the two most common no start issues, fuel and spark" was his was of telling you exactly what your issue is? You are on a public forum asking for solutions to your problem (rather rudely might I add) and you don't really seem receptive to the responses you are receiving. Does not seem like the best start IMHO
I'll try to look past the drama here. I sometimes I like to look at the questions posed on the forum and then search for a logical answer by going through the FSM. Basically to help my understanding. I realize you have a 80 with a 3fe...I don't have a FSM downloaded for this but here is an image of a 3f ignition. Total guess on my part but if the resistor between the coil and the ignition is worn would it cause this kind of problem?
Alternately you could just pose a question on the 80 forum and start over. The 80 guys may have more experience with the issue.
At the risk of being wrong, I'll toss in my idea. I was reading the other day about an EGR system removal. In the thread someone showed how they had moved one of their VSV's (Vacuum Servo Valves, I believe) and relay to the intake manifold. Another commenter stated that he'd removed all 3 of his with no ill effects. Then the prior poster expained the purpose of the one he retained; that when the engine is hot the ECU will send a signal to the relay to open this VSV which in turn sends vacuum to the fuel pressure regulator to increase fuel pressure for easier restarts when the engine is hot. I imagine bumping the starter shoots fuel in there so that when you hit it again it starts easier?
Now I don't know which one is which, but it should be pretty easy to figure out when you get under the hood. Mind you all the other threads I've read state they've removed the VSV without issues. Anyway, worth a look?
Now I don't know which one is which, but it should be pretty easy to figure out when you get under the hood. Mind you all the other threads I've read state they've removed the VSV without issues. Anyway, worth a look?
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EFI Relay.
Yeah, fuel pressure gauges are so simple to install. Every time I do an injected motor swap i find a place for a gauge. I can't remember how much time it's saved over the years. A clogged filter or weak pump can have the same symptoms as so many other problems.
At least half or the no run , poor run issues are fuel related. In my experiences it's probably been 75%..
It's nice to be running down the highway and have a gauge to check when the power seems off or you are getting a stumble .
Generally with fuel injection pressure is always supposed to stay within a small window. For example and LS1 will operate best around 55 psi +/- 3~5 psi. A GM throttle body 11-14 psi. Usually the regular opens to adjust flow buts maintain the same PSI. As you apply throttle the regulator opens up as fuel is needed to maintain the set PSI for the motor at whatever volume is needed. If the vsv is signalling the regulator it would be to increase or restrict flow not pressure. Your pressure shouldn't change. A weak pump can show a drop in pressure as the quickly throttle is opened. A slight change is expected but it shouldn't be drastic
The regulator will open as demand for fuel increases. If the pump is weak there will be a delay before the pressure catches up. All the pumps for these systems have the potential to build much more pressure and volume than is needed but the regulator keeps injector pressure constant by sending excess fuel back through the return. Without looking up the numbers for your
engine I would expect somewhere in the range of at least 45 -50 lbs going by most of the Toyota systems I've owned. If yours
runs at 48 psi at idle, for example, you could expect pressures to drop or raise 3 or 4 points in a healthy system as you open and close the throttle quickly but you wouldn't want to see it drop to 20psi under load.
On many systems bumping the starter cycles the fuel pump so if there is , for some reason, a low pressure situation in the fuel
lines or rails cycling the pump would repressurize the lines. A tight regulator should hold pressure in the lines after the pump
stops. If not the regulator then the fuel pump. Between the two there is usually a check valve somewhere that prevents
leak down in the system. If fuel is back feeding from the lines each start will take longer cranking times than normal to start
as the fuel has to be drawn back from the tank with each start.
Go to your diagnostics port on the passenger firewall. Connect Fp and +B terminals together. This bypasses the ECU, EFI relay, and the O2 sensors. If it allows you to start every time without bumping then it dials your search in on the above mentioned components. Cruisermatt mentioned EFI relay above (mounted on passenger fender well about 5 inches behind the air box).
If that doesn't solve it then I would start looking into the "MOD" that the previous owner did. The MAN-A-FRE ignition stuff is a point to consider.
If that doesn't solve it then I would start looking into the "MOD" that the previous owner did. The MAN-A-FRE ignition stuff is a point to consider.
It was the starter. The old fella was pretty weak and couldn't crank it fast enough to get the engine going, especially when it was hot I guess. Put a new EFI relay in while I was at it but did not fix the problem. New starter turned her much faster and she fires right up.
THANKS ALL
THANKS ALL