Jump to content

Help... it won't start, and I can't figure out why!


Recommended Posts

Ok, so I had the Comanche up on jackstands today. Was able to start it a couple of times up on the stands, no problems. After I put it back on the ground, it wouldn't start. I was working on the body and the interior, so I didn't do any engine work, besides changing the air filter. But now it turns over, sounds like it wants to catch, and even will briefly, but then dies. I thought maybe I had accidently messed up a vacuum line to the fuel injection system when I changed the filter, but I can't find anything wrong.

 

It's an 89 with the I6, 5 spd, 4wd. Any advice would be appreciated.

 

J.

Link to comment
Share on other sites

Boiler - I would guess that you might have bumped the fuel pump resistor, White porcelain conector, about 3" long, with 2 orange wires on each end, this is right above the air cleaner, and controlls curent to the fuel pump. and if you are cranking and will not start, the fuel is not getting to the rail.

Check this out first, Advance auto parts have this in stock if yours is shot.

 

Good luck ;)

 

Pete M supplyed the picture, we had this coulpe of weeks ago

Hope you don't mind me posting your picture of this Pete :bowdown:

Link to comment
Share on other sites

The fuel pump ballast resistor isn't necessary, it's only to make the fuel pump run quieter. The 87s don't have it.

 

Which means for diagnostic purposes you can just jumper the two wires together. If it starts and stays running, you've identified the problem. Since you changed the air filter, there's a good chance you may have whacked that thing without realizing it.

Link to comment
Share on other sites

Ok, so I jumpered the fuel pump resistor and still no luck. Pulled the plugs and checked them over, and they're fine. The truck will catch once in a while, and run for a second or so, but when it does, it runs so rough as to shake the entire truck. So I'm at a loss. Any other ideas?

 

J.

Link to comment
Share on other sites

No, no welding work. Just sanding and removing decals to get ready to paint. I did mess with the transfer case for a short time, but that doesn't have anything to do with the engine running. I double checked the vacuum lines to it just to make sure they were hooked up..... not even sure if that would have anything to do with the engine starting. Like I said, I'm at a loss.

 

Is there any way to check the that the fuel pump is working correctly besides getting a pressure guage?

 

I just don't understand this, because I was able to just reach in and start it two or three times when it was on the stands, and now it won't run. I know it's probably something simple, but I can't find it.

 

Thanks for the help so far.

 

Josh

Link to comment
Share on other sites

here's a quick way of seeing if the pump even works, turn the ignition to on and listen for a humming sound coming from the gas tank. should humm for a few seconds a least and then stop. don't turn on the engine when doing this just turn key to on. your guages and lights should come on but not the starter to crank it over. if there is no humming then i bet the pump isn't working for some reason, maybe a wire got jarred lose when you took it off the stands? if there is a humming then i would say the pump works but the fuel might not be getting to the engine. i know the fuel line is metal except for the connector hoses for the filter but i'm sure you have noticed if you accidently crushed it with the jack. also check for any blown fuses. kinda strange why it would start on stands but not after it's back on the ground.

Link to comment
Share on other sites

I finally got some time to spend on the Comanche. I disconnected the fuel line from the fuel rail and put it in to a bottle and cranked it over, and I am getting fuel. Now what? I've jumped the fuel pump resistor, so that's not in the loop any more. But, unlike before, when the engine would catch a little, now it doesn't at all. So I don't know what to do now, except yell for help. I know I need to now check if I'm getting spark, but I can't do that until I get someone to help out here (I live in the sticks). Any other advice?

 

J.

Link to comment
Share on other sites

try fogging some ether in the intake. If it cathes you've got a fuel problem, if not it's spark.

To test for spark rig up a remote starter wire. Pull the green wire that goes to the start, and jumper it to the positive terminal of the battery. Make sure it's not in gear, the motor will turn over.

Link to comment
Share on other sites

the make a spark plug tester you can use to make it easier or make a push button start and hook it up to the starter so you don't need a partner for help. You can look up how to make the push button starter that just uses clamps Like a jumper cable just smaller connected to the starter. Just trying to help you solve this ASAP.

 

Cole

Link to comment
Share on other sites

Ok, so I blasted it with starting fluid and it fired for a few seconds. Guess I have spark. So, do I now start with the fuel filter? Then work my way down the line of the fuel system? It hasn't been ran out of, or run low on gas, but the gas is a little old. I couldn't see that being the whole problem, but maybe contributing to it? Guess I'll start with the fuel filter, and maybe drain the gas out and get some new stuff. How hard is it to drain that tank?

 

J.

 

Thanks for all the help, by the way.

Link to comment
Share on other sites

I had an issue like that with my truck a while back. and it turned out to be a ground wire off on the engine block. Its located on passenger side just above and to the back of the oil sending unit. I can't say thats your problem. just an idea.

Link to comment
Share on other sites

Ok, so I blasted it with starting fluid and it fired for a few seconds. Guess I have spark. So, do I now start with the fuel filter? Then work my way down the line of the fuel system? It hasn't been ran out of, or run low on gas, but the gas is a little old. I couldn't see that being the whole problem, but maybe contributing to it? Guess I'll start with the fuel filter, and maybe drain the gas out and get some new stuff. How hard is it to drain that tank?

 

J.

 

Thanks for all the help, by the way.

 

How much gas is in the tank? If less than a 1/4 tank I wouldn't worry about draining. You are right to start with the filter, its a easy job and should likely be done anyhow.

 

After that I would check the fuel pump. When you first turn the key, before the starter catches, you should hear the pump prime the line. If you don't, its likely the pump is shot.

 

Try that and get back to us.

 

Good luck,

CW

Link to comment
Share on other sites

The tanks about 3/4 full, so I think I'll drain it. I can hear the pump humm, so I think that's ok. I get fuel out of the fuel line running into the fuel rail for the EFI when I crank it over, but I don't know if it's enough. Guess all I can do is start at one end and work my way to the other.

 

The ground strap looks ok.

 

Thanks,

Josh

Link to comment
Share on other sites

have you pulled the injectors to see if they r good. I knwo you tried most of the others but if fuel is getting to the rail and it fires with starter fluid then maybe fuel isnt reacing the injectors or coming out incorectly.

 

Cole

Link to comment
Share on other sites

Boiler - How long did you have the Mj on the jack stands?? and when was the last time you started it, that it ran?? If you had it sitting for couple for months, even 2 months, the gas might have gone bad, if you take off the gas cap, and it smells like Varnish, thats bad gas.

 

You can save some trouble by adding Fuel Stabilizer to the gas in the tank, but still change out the filter. Let the Stabilizer sit over night, and see if it will start and run.

Link to comment
Share on other sites

Even with bad gas it should at least try to start. The gas in my 88 was almost 2 years old when I finally fired it up, but the truck still ran. It ran poorly, but it ran and idled. I dumped in some stabilizer and some octane boost and it ran and drove just fine.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...