Turns over, won't run

[moby14]

We recently got a 1994 Ford Explorer that didn't run for a year and the owner wasn't sure what was wrong. So far, we have determined it may be an electrical issue, so we replaced spark plugs, spark plug wires, and the coil pack. After this replacement, more cylinders fired but t still would not come to life. Also, when it did fire, it backfired three times in about 3 seconds, ran extremely rough, and died. I'm guessing this may be firing order, but are there other things that can cause this guy to not run? We've eliminated the fuel issue so that is not part of the problem, but any suggestions are helpful suggestions.

 

[trashtruck]

check the fuel pressure. you can rent a tester from the parts store. just because it's getting fuel doesn't mean it's getting enough. verify fuel injectors are functioning. using a long screw driver, listen for all 6 injectors to "click". verify firing order is correct. 1,4,2,5,3,6. verify all 6 plugs are firing from the coil pack. use a spark tester to see if all 6 connectors on the coil produce spark. if not, it could be a bad coil pack or there may be an issue with the icm or it's wiring. check for air leak.

 

[moby14]

how exactly do you test the fuel pressure?

 

[trashtruck]

with a fuel pressure tester, available at most parts stores. it should have adapters to connect to the valve on the fuel rail. valve should be on the pass side near the fuel pressure regulator. ideally you should get between 40 & 60 psi running.

 

[moby14]

with a fuel pressure tester, available at most parts stores. it should have adapters to connect to the valve on the fuel rail. valve should be on the pass side near the fuel pressure regulator. ideally you should get between 40 & 60 psi running.

My local auto parts store has no fuel pressure testers available but I will attempt to get one and test that this evening. Also verified that the firing order is correct. Where is the ICM located, I would like to try that next. I am also dropping the fuel tank this evening if I can't find a fuel pressure tester. I think what may confuse me the most is that I can't even get it to turnover while using starting fluid and after using the starting fluid and turning it over it will backfire. But due to the new spark plugs, spark plug wires and coil pack i would expect that it has enough spark. What else might keep it from sparking?

 

[trashtruck]

from my haynes manual:
engine backfires-
1;emissions system malfunctioning
2;fault in fuel or electrical system
3;faulty secondary ignition system (cracked plug insulator, faulty plug wire)
4;fuel injection system malfunction
5;vacuum leak @ throttle body, intake manifold or vacuum hoses
6;valves sticking
7; crossed plug wires
icm is located behind battery, along radiator support

just because a part is new doesn't mean it's good.

 

[moby14]

thank you will keep you posted on how things go

 

[natenkiki2004]

Start simple. Spray starting fluid in the intake (disconnect MAF and intake tube, shoot it at the throttle body) and see if you can keep it running or if it smooths out. If it does then you know it's a fuel issue. Check pressure, if there's enough then it may mean your injectors are buggered from sitting or possible contamination.

If the starting fluid makes no difference then you know it's an electrical issue. There's not much to mess with on these engines. Timing chain doesn't stretch enough to cause an issue and will likely never jump. The computer handles the advance. If you feel it's electrical, the first thing I'd suggest is to unplug sensors. IAT, ECT, MAF, TPS. Unplug them one at a time and see if any of them make a difference. It could be that the engine thinks it's 200 degrees out or that the engine is warm and thus it doesn't feed it enough fuel for a cold start.

 

[decipha]

did it backfire through the intake or the exhaust


an intake backfire is lean out from not enough fuel

an exhaust backfire is an ignition failure

 

[moby14]

After pulling numerous sensors and trying time and again to turn it over without success I got lucky with a sensor and was able to use starting fluid to turn it over. At this point it was determined it was a fuel problem so we went onto dropping the tank and found out the fuel pump was not pumping so we replacing that today.

 

[trashtruck]

another gen 1 saved! glad to hear it's back to running.

 

[moby14]

Yah I took it off someones hands on sunday who wanted nothing to do with fixing it and now its all better