Injector testing hack

I was wondering if I could use the fuel pump priming circuit as a timed circuit ,to fire an injector during a leak test, by installing a jumper switch onto the inertia connector to toggle between pump priming and injector firing. It seems I would have to ground the injector and feed it this priming signal to energize it . This being a 2001 Ford exp 4.0 sohc. Your thoughts?

So, you're thinking about using the load side of the fuel pump relay to run a single injector for the two second prime, correct? Because it'd be a repeatable amount of time.

Yeah, you'd have to ground the other side of the injector to make it work, but you'd definitely get the injector to open. I think the issue would be washing out the cylinder, and possibly causing hydrolock. Two seconds of on-time is a TON for a fuel injector. For reference, the OTC Fuel Injection Pulse Tester only uses 1/2 second total intervals.

Thanks Tyler.I feared that would be the case. Is there a thread I can read that explains the loop strategy for Ford? My action 9580 tool indicates clsd( obvious) open1,open2,clsd1, .it seems open1 happens at both fuel enrichment(wot)and deceleration(fuel cut out),I think clsd1 is when a lean bank o2 is ignored and is made to follow the good bank via trims, and open2 happens when both o2s are ignored and defaults are used.my bank2 is maxed lean after wot-Decel, at times bk1 goes lean, then open2 happens.I need confirmation on these thoughts.(I've looked@@@)
That's why I think an inj. Leak test is needed. They are firing but I feel they are intermittently clogged.if these are good then it's time to pull heads..BTW it has 250,000+ miles.thanks truly

I dunno that we have a dedicated thread for Ford's various loop statuses, but I can tell you that you're on the right track with your thoughts about what the scanner is showing you.

Ford calls WOT and fuel cut deceleration 'Open Loop Driving', which correlates with Open 1. It also has 'Open Loop Fault' when it does the borrow-trims-from-the-other-bank thing. That may be Clsd 1 like you're thinking, but I'd want to see the trims move in step to make sure.

I usually only see Open Loop Fault when there's an O2 problem, are you getting any codes? It usually takes a P11xx (O2 stuck) code to make OL-FLT happen.

Everything you said Tyler makes perfect sense. Thank you. I got both 1151,2 and 1131,2 codes. these are new O2 sensors. When in open loop fault, clsd one, I'm not sure if the Ford strategy actually substitutes a stuck lean open value(.00) at this point in the tool, (reply only needed for this point) or if the o2 is actually pegged lean causing both stft and ltft to max out lean or rich, on either one or both banks. (Its both random, intermittent and on decel for sure.)When both banks are maxed for 60 seconds, it goes open2 where pcm takes over, seems to peg o2s to 0.00,then runs perfect. to me a reasonable thought is intermittently clogged injectors,exhaust manifold leaks onto o2s..compression was even all around.hope this might help.

For my info, were the O2's replaced in response to the P1151 and 1131? Mostly trying to establish if this issue was present before the O2 swap, or might have been introduced by the replacement parts.

I'm not positive what exactly the strategy is when those codes set, but a lean default wouldn't surprise me. One thing you could do is monitor all four O2's, upstream and downstream, when this issue occurs. If you're in closed loop, and the upstreams are pegged lean but the downstreams are saying full rich, then suspect the upstream O2's. If the downstream sensors agree with the upstreams, then suspect a genuine lean mixture. Make sense? This video demonstrates the concept perfectly:



I understand why you're suspicious of injectors, but I'd be very surprised if that were the case. Clogged injectors usually cause high trims all the time, and don't come and go at will. I'm not saying it's not possible! Just that I've never seen it before. Same for exhaust leaks. It's my experience that the leak has to be pretty huge to skew fuel trims significantly.

O2s ,plugs wires ckp,iac,pcm been replaced, classic parts changer... That's why I was trying to help this friend. That's also why I have been leaning toward internal engine problem. Just found out he cleaned out rear cat. That's why rear o2 is changing quickly. Just suggested to pull valve covers and check lifters, some knocks going on, so ending thread here. You've been an immense help. Thanks. Onto tackling my Ridgeline po848. And p0420. Ouch! See ya.

www.google.com/aclk?sa=l&ai=DChcSEwj1sYj...RKYDlgQpysIMw&adurl=
I use this super cheap injector timer tool. I keep old injector connectors off bits of scrap harness to make it easier to hook up