'73 FI type3 refusing to start

[nitro_warrior]

Hoping you can give me some ideas, i'm at a bit of a loss with my Fuel Injection type 3 not starting.

Its a project car which I got in an non-running state. Earlier in the year I got it running and it was ok, would idle unattended, needed a bit of a tweak but was ok. But after I fitted the air filter its not wanted to start. Now when I remove the air filter and revert it to how it was it still doesn't start.

If I pump the throttle 20 or times it splutters, no more than each cylinder firing once. If I don't pump it doesn't do anything.

I get a spark, and there's fuel in the lines.

To help with the spark I was running jump leads from another car which helped a little bit.

I also tried bypassing the fuel pump relay to keep it running the whole time. That made no difference.

On the rare occasion it does bite and run (without the airfilter on), it will only keep running with constant pumping of the throttle, you can't hold it at low or high revs to keep it going. And it backfires loads, but I think the backfires come through the inlet.

The final thing is the coil gets really hot, too hot to touch hot.

Actually the final final thing is, using dreaded cold start (which didn't really help, runs briefly on the cold start but doesn't bire) I had a small fire when flame came back out the air inlet and catch some of the cold start that had spilled out.

So before I blow myself up or set the car on fire, any ideas? I'm a bit stuck. Cheers.

[KTPhil]

Find out why the coil is hot. Points bad? Timing bad? Wiring short? (backup lamps get power there). Blame the FI last, not first.

You probably knocked off a wire connector or hose end when you fiddled with the air cleaner. Check meticulously for those problems, which will prevent starting.

[BrianD]

First check the coil's resistance with a multimeter as well as your voltage regulator (under the back seat), then check your fuel pressure (install a gauge at the "T" between injectors 3 &4 ). It should be at 28 psi. Have you checked your timing? You can static time it to get you started. Also check your dwell and your valve clearances. I'd also look at your spark plugs and make sure they have the correct gap spacing.

[nitro_warrior]

Thanks for the suggestions.

Yeah i think the FI is probably fine. I suspect it's more simple.

I was thinking about the fueling. It splutters after pumping the throttle. And when it runs it only runs when pumping the throttle.

I disconnected a fuel line at one of the injectors to make sure there was fuel there, it dribbled out, but presumably at 28psi it should spray out?

I've just ordered a fuel line tester from ebay. To check.

Thinking about the coil, I remember it being hot before but forgot about it when it was running ok. What resistance should the coil have?
I remember someone saying once that electronic dizzys have different coils to mechanical dizzys. Could the wrong type be fitted? Is there a way to tell?

Cheers!

[KTPhil]

So you are running pointless? That might be where your problem is located.

[JSMskater]

this all started when you removed the air cleaner. start there.

the grounding porcupine is underneath the aircleaner, attached to the nut on the oil breather. did you pull one off, or is it damaged in any way?

the TVS is nearby there, is it still seated in the plug?

did you remember to re-attach and clamp the hose from the air cleaner to the AAR? is the hose from the AAR to the IAD in good shape?

re-check the points, timing, and other ignition components.
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[nitro_warrior]

I'm not running pointless. I do have a new pointless dizzy in my spares, I also have a new coil for it in my spares that I could try, but I understand the coils are different?

I should stress, when I got the car it didn't have an air filter. When I had the car running there was no air filter (or any of the breather hoses) attached. It took me ages to source a FI air filter and it was only after that was fitted I had problems. I'll certainly check the nearby wiring though as it may have been knocked.

I think something to do with the increased "resistance" of the breathers and filter being plumbed in may be relevant. I'm also concerned that when it does run (without the air filter) it seems to back fire through the air intake system. The extra pressure when the filter is fitted may prevent the backfire through the intake but is also stopping it starting.

I'm hoping the back fire is timing related, and my money at the moment is on low fuel pressure. I have a fuel pressure sensor enroute. Hopefully get a reading in the next few days.

[KTPhil]

Oil bath air cleaners are extremely low resistance, so that's not it. Maybe the hoses to the air cleaner are installed on the wrong nipples, messing up the vacuum signals and airflow?

[raygreenwood]

[nitro_warrior]

Thanks for the suggestions, I think we might be on to something.

Maybe it was hideously lean...

My fuel pressure reader arrived and I tapped it in.

I flicked the ignition a few times to prime the system but the gauge stayed at 0 psi. So I by passed the pump relay to run the pump continuously.
The pressure slowly climbed to about 22 psi, at which point the needle flickered and the pressure started to drop, slowly back down to 0 psi.

Repeating the process yielded similar results. So I think I may have found the issue.

How well do these systems hold pressure over time?

So pondering the duff pressure... the car was largely in bits when I got it so there are a few unknowns. Which way round is the fuel pumped? And therefore where should the pressure regulator be positioned? Mine is before cylinder 1. Come to think of it i'm not sure it's on the right way round. Certainly I had the pump off and in a bath of diesel as per the FI help thread and the pump itself seems to work ok.

[Tram]

[raygreenwood]

[Mike Fisher]

I believe my fuel pressure regulator is After #1 just before it goes into the Return fuel line.
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69 FI/AT square Daily Driver
66 sunroof,67,70,71,71,71AT,72,72AT,73 Parts
two 57 oval ragtops sold
'68 Karmann Ghia sold

Society is like stew. If you don't keep it stirred up you end up with a lot of scum on the top! - Russ_Wolfe/Edward Abbey

[Bobnotch]

You could try pinching the return hose between #1 and the regulator, and see IF the pressure raises. If it doesn't, then the pump is kaput. I've had several pumps run, but not build pressure. I just replace them with the ranger pump (Airtex E2000), and I'm good to go.

Here's how the fuel system is set up; out of the tank (the nutted fitting) to a fuel filter, then to the "S" port on the pump. From the pump "D" to the left (left is driverside in the USA) metal tube into the tunnel (note; there should be a round disc shaped fuel dampener in this line. If it's there great, if it's not, that's ok too). From there it exits out the rear of the tunnel (gets hosed) to the #3-4 injector set, then hosed out of there to the #1-2 injector set (note; some cars have the cold start valve plumbed in here off the extra fitting, and some cars don't (depends on the year of the car). If yours does, then plumb it in for now, as it can be plugged later). From there to the pressure regulator, then hosed out to the right side of the tunnel. Exiting the right side of the tunnel to a "Y" (this is also gets hosed from the "R" port on the pump) then back to the fuel tank (the other fitting on the bottom of the tank). If your car is hosed like this, then it's correct. If not, then you need to correct it.
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[nitro_warrior]

Hoping to get some time at the weekend to follow all your suggestions. In the meantime I had another quick look to see if pinching lines would lift the pressure.

However it behaved a bit differently. Again the brief kick from the pump when the ignition is turned wasn't enough to do anything. So again I bypassed the relay to run the pump continuously.

It took a good few seconds to do anything then I could hear the pump note change as it pumped fuel and the pressure increased to 28psi and stayed there, but as soon as I turned the pump of it dropped quickly back to 0psi.

Repeating it did the same thing, so even after just pumping fuel, it struggled at first to gain pressure, but then climbed to 28psi, and fell back to 0 as soon as the pump was off.

What holds the pressure in the system once its up to 28psi? The pump and the pressure valve? If it gets to 28psi does that suggest the pressure valve is ok and the fuel is loosing pressure back through the pump?

I'm going to hopefully get a good route around at the weekend to check all the plumbing.

[raygreenwood]

[josh]

I would also make sure the gas tank is clean. I've had similar issues caused by crap building up around the outlet from the tank.
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[nitro_warrior]

Well some progress.

Tonight I took the pump off, then following this guideI was directed to, I dismantled it.

The first thing I noticed was that I couldn't see the Pressure Release Valve PRV in that it was stuck in. That would explain why it wasn't holding pressure. But I couldn't do anything to get the PRV to move so I took the back plate off.

Now it didn't exactly explode apart, but I had a moment of head scratching as I only had one big spring that didn't seem to push the valve all the way in. On inspection of the diagram I noticed there must be a 2nd smaller spring. But I couldn't for the life of me find one on the floor that might have sprung loose. So i'm 70% sure it's been dismantled in the past and the little spring omitted.

I happen to have a box of random springs, so I picked one that fitted, crossed my fingers that the stiffness was ok and reassembled.

Unfortunately only partial success. The system now holds pressure, but only at 10psi. I guess my spring isn't strong enough and the PRV is releasing to early, letting the fuel get back to the tank as in figure 3.

I suppose I can try a stronger spring but I suspect it's new pump time. Or there's the long shot it's go air in the system and well settle out over night!

[nitro_warrior]

Well reading some of the other threads I found a picture to clarify what small spring I was talking about

From here

I'm sure that spring wasn't there...

The spring I put in probably wasn't as big as that, so I think I will swap it for a bigger one, seeing as I have some.

Failing that i'll track down a new pump. But why a Ford Ranger Pump? They look like normal electric fuel pumps, is there anything special about them?
If that is the case I might just go for a generic one, seeing as i'm in the UK they are a bit easier and cheaper to get my hands on like this one on ebay

[Mike Fisher]

The pump on Ebay has too big of inlet/outlet nipples at 10 & 12mm! You want 7-8mm or 5/16" inlet/outlet.
_________________
https://imgur.com/user/FisherSquareback/posts
69 FI/AT square Daily Driver
66 sunroof,67,70,71,71,71AT,72,72AT,73 Parts
two 57 oval ragtops sold
'68 Karmann Ghia sold

Society is like stew. If you don't keep it stirred up you end up with a lot of scum on the top! - Russ_Wolfe/Edward Abbey