Hard To Start / Runs Rough / Variable Idle

I recently purchased a 1985 Toyota Van (5 speed), which I shall refer to as "Red Stripe".


Red Stripe was advertised by a woman who said the van had sat without running for over 10 years. Upon further inquiry, it looks like it was closer to 17 years! 112,xxx miles on her. Red Stripe, all those years ago, was rammed by a runaway vehicle (huge dent in side right behind driver's door. Had to replace battery by dropping the batter​y box and re-raising with new battery). She said she drove it for another six months, then replaced it with the insurance money and Red Stripe just sat until I came along.


I changed coolant, oil, new oil and fuel filters, new plugs (but NOT wires, cap or rotor), dropped fuel tank and replaced bad pump. Did not clean tank, but did rinse it with a few gallons of fresh gas. I got her running and she smoked terribly for a few miles or so, then cleared up and was running great!


Then a brand new section of soft fuel line failed, spilling gas everywhere. I replaced that section with a ridiculously high PSI hose and it did the trick.


Then the alternator died and I replaced that. Immediately after that, when I would start the engine, it would idle up and down, rhythmically. throttle would kill it, until restarting it a few times, when I was then able to carefully rev it up. Once it came back to idle, it would die. I changed the fuel filter AGAIN, no change.
This is where it is at now, except that it has got more difficult to start. It will eventually start and run rough, but it takes a lot of cranking; most normal people would give up before cranking it this much. Unfortunately, I'm not normal, and I think I might have fried the starter, as it just started making a funny noise.


Since the problem coincided with alternator swap, I wondered if maybe I knocked something loose, like a vacuum hose (and I think I MIGHT be hearing a sort of whistling, but not sure). I've inspected all the hoses I can see and all seem ok. I did find a busted wire to the O2 sensor, and repaired the connection at the plug (not a great permanent fix, but confident it's making proper contact). No change.

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Wondered also if it could be fuel pressure regulator or dampener. Could that burst fuel hose have been a victim of unregulated pressure, or just a defective part? (I can't be sure they sold me the right PSI hose).


All of this is within the first 50 miles since I bought it.


This is the 4th of these vans I've owned (all '85s), and I currently have 2 (both 5 speeds). I don't have much of a mechanical background, but I've done a lot of work on these vans and I'm learning a lot--but there are large gaps in my knowledge for sure.


Any ideas and suggestions welcome, thanks!

1st off, there should be no rubber hose in the fuel system except for the 2 short pieces at the inlet and outlet of the fuel filter. I've never tried anything other than OEM hoses that have permanently crimped fittings. If I did, since the fuel pump puts out around 50 psi, I would make sure the hose used would be rated for at least this high.

There's a large black intake air hose that runs from the AFM (Air Flow Meter) to the Throttle body. It's common for these to become brittle and crack. When cracked the van will run bad especially when you try to accelerate. This is because the engine torques away from the AFM and stretches the hose. When stretched the crack opens more and the van wants to die. About in the middle of this hose there is a connection on the underside. There's a metal fitting (tee) that goes into it. It's easy to see the smaller hose on the front of it, but there's a bigger hose (about 3/4") that attaches to the back of that tee (air valve hose). It's very likely the air valve hose has been damaged or disconnected from the tee (and that could be at least part of the problem). One way to check the throttle body intake hose for cracks is to start the van, then grab the hose and squeeze it. If it's cracked, squeezing will cause the crack to open and the engine to stumble and/or die.

Don't worry about the FPD (Fuel Pulsation Damper) unless it's leaking. There's nothing to break here except a diaphragm inside. When that breaks fuel will leak out of and that's a huge problem. Don't mess around with a leaky damper. It will leak onto your hot exhaust manifold and likely start a fire. Leaky FPD's have been the cause of several van fires. Don't let yours be one of them. Tim

Thanks Tim for the reply!

The large intake hose seems to be in great shape and has already passed the squeeze test. I will double-check the smaller associated hoses. The rubber fuel line is indeed just a short section from the fuel pump to hard line. No leaks anywhere anymore. I will try to post a short video of the engine running which shows the erratic idle...

Here's a short video of engine idling:
https://www.facebook.com/photo.php?v...type=2&theater

Yes, check that and check all your other vacuum hoses to make sure they're connected and undamaged (especially the big ones). You should also check the ECU for trouble codes. Good luck. Tim

Checked ECU, all is clear. Couldn't find any vac hose issues. Next thing maybe check fuel pressure? And of course replace the starter that I apparently fried :pissed:

This is just my gut, but based on that video I don't think it's fuel pressure related.........I think it's a major vacuum leak. Assuming that's the case, another way to check is to spray carb cleaner or another similar flammable liquid around the suspect places. When you get close to the leaky spot the engine will speed up. Just keep in mind that this method can be dangerous so take precautions and only do so at your own risk. Tim