Need some real help here with engine not starting

[ScoobyDooJeep]

I'll try that method. I have nothing else to loose but time. I'm about to give up. I've done just about everything I can think of and I'm not getting anywhere. No better, no worse. Just won't start. What I have found is the #1, 2 plugs are getting black where the other ones aren't. It seems if it's only hitting on one or two cylinders too. I even too the injectors out and replaced them with the spare set I had from the other motor that was blown. Watched the spray pattern before I reinstalled them. Looks like a good spray and they all worked. Now I'm leaning back towards the spark issue. Maybe one of the sensors is telling the computer something. I had extra coolant sensor so I changed that out too. Nothing doing.

I do appreciate everyone's advise. I'll keep plugging away at it. Just glad it's not my DD.

 

[B.RAIDER]

I know your 91 ignition system is a little different from my 88, but what about your Pick-up coil.
Just another thought..............

 

[HttpWayne]

Make sure those first two wires weren't destroyed in installation. I know the number 1 wire is a pain for me sometimes. Those heater-core hoses are right in the way, and last time I needed to replace them they were hot as hell. I used needle nose pliers to shove it on and still burned my hand. I've been meaning to inspect it to make sure I didn't destroy it internally. That alone could cause a weak spark, leading to poor combustion and sooty plugs + injectors.

After you get that sooty problem sorted out I would put half a can of seafoam in the tank with about a quarter tank left, then fill up to half. Then put the other half in a cup and submerge the brake booster in it (leave it attached to the manifold and put the brake-booster end in the cup). Do this while it's running and there is about 2 grand of throttle in it. It will suck it in and bog down, maybe even shut off. If it does let it sit for about half a minute and then crank it back up. It'll take some cranking to get it going again. As soon as it does throttle it up so it keeps going. Your exhaust is going to smoke like a chimney so don't do it while you're still at the gas station.

 

[ParadiseXJ]

It will try to start when I hold the gas all the way to the floor.
Any help would be great.

Try a short crank to see if it starts. If not, have a buddy spray some starting fluid or carb cleaner down the intake. If it fires, you are not getting fuel (injectors not working or no fuel pressure)

Ok, It did start after I pushed the pedal all the way to the floor.

Possibly the TPS if pushing throttle down made a difference.

What you said about holding the pedal all the way down sounds suspicious. If you do that before you start cranking and hold it down, it tells the ECU to shut off the injectors to help clear a flooded situation. Black plugs say you are running way too rich.

With fuel injection you should not have to push the pedal at or before start-up. Try the starting fluid route with your foot OFF the gas, key, 1-2-3 start.

If the fuel system is working properly you shouldn't have to hit the gas until you take off.

 

[ScoobyDooJeep]

With fuel injection you should not have to push the pedal at or before start-up. Try the starting fluid route with your foot OFF the gas, key, 1-2-3 start.

If the fuel system is working properly you shouldn't have to hit the gas until you take off.

Yes I know this. I was seeing what it would do and not do based on the full throttle. My understanding is that it shuts the fuel off with full throttle. I was trying to figure out what that meant in my situation. The only time it did fire off any at all was when I was holding the throttle all the way down. Then it only ran for a 15-20 seconds and not correctly.

Small update. Last night I hooked the test light to the spark plugs and found to have good spark at all of them. Hooked up fuel pressure gauge and it read almost 40 when cranking. Also tried the starting fluid. Nothing doing there. So right now what I'm seeing is that I have fuel and spark. I'm thinking is it's just not firing and getting fuel at the correct times. Which one would think is timing. Again, I haven't moved, pulled or messed with the dist in any way other than replacing the cap, rotor and wires. Have checked and rechecked all that stuff and it seems to be correct. I didn't mess with or remove the timing chain or cover at all.

 

[HttpWayne]

Something else just occured to me, you didn't get any of your injectors swapped around when wiring them back up did you? I remember 2 sets of mine were quite confusing as they looked like they could go either way.

Also, I know you didn't do anything with the ignition, but you might want to check out your ignition coil. Seeing a spark, and having strong spark are two different things. If it has so much as a paper thin crack in it (dropped it or dropped something on it) it won't work. You might see some blue spark, but it won't work. That happened to me. My dad dropped mine when we were swapping things over to the new one. He didn't think anything of it and neither would I. But that was what kept it from starting.

 

[ScoobyDooJeep]

Something else just occured to me, you didn't get any of your injectors swapped around when wiring them back up did you? I remember 2 sets of mine were quite confusing as they looked like they could go either way.

Also, I know you didn't do anything with the ignition, but you might want to check out your ignition coil. Seeing a spark, and having strong spark are two different things. If it has so much as a paper thin crack in it (dropped it or dropped something on it) it won't work. You might see some blue spark, but it won't work. That happened to me. My dad dropped mine when we were swapping things over to the new one. He didn't think anything of it and neither would I. But that was what kept it from starting.

Well, I bought a new one and installed it but I will check it to see that it's putting out what it's suppose too.

 

[HttpWayne]

If you have spark and the proper fuel pressure (and the crank sensor isn't bad), there's only two things it could be that I can think of.

Either your cat is plugged (highly unlikely) or the timing is out.

Your crank sensor IS plugged in, isn't it? I've made that mistake before

 

[djgrayxj]

What is the voltage to fuel injectors?
http://www.naxja.org/forum/showthread.php?t=40941
OP by BSD: 12-2-2004
I just replaced my fuel injectors. One of the cylinders was not running. All was fine before. I am getting spark but doubt I am getting fuel to it. I have voltage on the plug that goes to the injector. However, I do not know if it is the right amount. It also seems to vary when I checked at another plug.
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No Conclusion to this post [I hate poster that never finish a post] but you will find some good information on 91+ injector electrical.

 

[ScoobyDooJeep]

Well, I'm officially giving up on this. I'm pulling it to my buddies shop so they can work on it. I've tried absolutely everything I can think of. I've changed out distributors. I've moved it 180 around (even though I never originally removed the dist). This is the strangest thing I've ever seen.

 

[HttpWayne]

Anything new. ?