87 22re won't start without gas/throttle
 

My 22re died on the way home the other night and now it wont start or stay running without giving it gas and feathering the throttle. When I get it to start, it runs like crap ... like its getting the wrong mixture of air/fuel or like the timing is off.

I have:

Replaced the fuel filter and dropped the gas tank. Fuel pump kicks on with power (tested physically at fuel pump and using jumper method')
The computer/blink codes were pointing to the TPS so I tested/replaced TPS (though I didn't 'dial it in')
Codes were wiped to only show check engine light and battery light with the key 'on' and no blink codes when in diagnostic mode.
Alternator then tested bad at a parts store so I replaced that as well. Still shows check engine light and battery light with no blink codes.

Spark has been verified at one of the the plugs in efforts to eliminate an issue with the ignition. Plugs/wires/cap/rotor were supposed to have been replaced a few thousand miles ago as part off a tune-up at a shop and truck was previously running great.
Plugged/stopped the vacuum to the EGR and still no start without giving it throttle
Plugged/stopped the vacuum to the FPR and it seems to turn over quicker want to start but still no start without giving it throttle

That's the first thing I would check. $30 for a timing light, which you should have anyway.

Note that you need the jumper AND the tps at "idle" to reach base timing. If your tps is not closing the idle switch (at idle), you won't be very close on the ignition timing.

Ive adjusted my TPS as explained at 4crawler and purchased a timing light. However, the truck will not idle, run, or start without constant throttle/high revs so I'm not sure I'll be able to adjust/verify timing in its current state.

https://cimg3.ibsrv.net/gimg/www.yot...271563e308.jpg
Replace the fuel pressure regulator

Is there a sure way to test it? I thought I had ruled out the FPR by pulling and plugging the vacuum hose on top verifying that it wasn't leaking from the nipple (no broken diaphragm) with the vehicle running? I also didn't realize that a faulty FPR could prevent the vehicle from running altogether. Cheers

yeah, don't just throw parts at it. diagnose it, and figure out what exactly isn't working correctly.

an FPR is pretty easy to test and confirm good/bad, so just replacing it without testing is a recipe for disappointment.

I would start with the intake piping, the accordian hose has been known to crack and you wont see it if its on the bottom side. This will effect both the fuel mixture and the fuel pump energizing circuit.

​​​​​next if you have the stand alone style idle air valve, it's air hoses if leaking cause similar issues.

Finally inspect the rest of the vacuum system, PCV system, and ensure your air filter isn't blocked with dust.

There is an idle adjustment screw on top side of the throttle body, it's about half an inch around and fits into the molded section of the throttle body (do not confuse this with any dof the stop screws on the side of the throttle).. Ensure it has a good squishy oring.. The factory base setting is "All the way in, then out three full turns", this is baseline setting and it will need adjusted with an accurate tachometer connected.

So now you have no known air leaks and an idle adjustment near spec.

Pull the intake hose off, inspect the throttle plate is very slightly cracked (less than 1mm) about the thickness of a piece of construction paper. Ensure there is no tension on the throttle cable, it should be just barely slack, and adjust the throttle stop a half turn at a time until you have this slight crack.

If it doesnt start at this point... Hook up your timing light and have someone crank it over while you look at the timing it should be in the five to ten degrees range while the key is held in the start position. If it's not in the ballpark adjust it bit by bit.

If it still doesn't start.. Run the fuel pressure and volume test.

Our first gen vehicles weren't engineered with 10% Ethanol in the picture... I believe part of the problem with the fuel pump and fuel regulators is due to Ethanol... the seals, diaphragms, rubber lines just aren't Ethanol resistant...