ictyotafan

I have a 91 4x4 3.0 that starts up and sputters for a few seconds before it dies. So far, I have replaced the ECU, CO relay, MAF, ignitor, coil, efi relay, ignition switch and the fuel filter. I removed the fuel pump and it appears to be pushing enough fuel. Any help would be greatly appreciated.

yayfortrees

Hey yota fan, are you in Wichita? If so, you're close to me.

How and when did this problem start? Suddenly or slowly? Have you taken any compression readings? What do the spark plugs look like?

Right now, the good news is that your truck has lots of new parts that won't need to be replaced for a very long time. The bad news is that your truck didn't really need most of them. Let's start some diagnosis work on it before throwing any more parts at it. Judging from your list of parts, a trip to the stealership would have been less expensive.

Give us some answers to the questions above, and let us know what you find out or have already done. We'll get this thing figured out.

ictyotafan

Yep, good ole Wichita. A few months ago, I had the heads rebuilt. During this time, I replaced everything from there up, including the plugs, wires, distributor cap, and rotor. A few weeks ago, I put on a new exhaust and a new oxygen sensor. I drove it for a few days and decided to disconnect the battery to see if I was getting any codes. The next morning is when all my problems started. I am going to try and get a fuel pressure tester tomorrow and check that. It was running lean before the exhaust and o2 sensor were changed.

yayfortrees

Cool! I'm located about an hour east of you, near Eureka. I'm in Wichita quite a bit.

So I'm assuming you had the heads rebuilt due to high mileage? What about the bottom end, has it been rebuilt recently? How many miles on it?

Have you taken any compression readings? You probably already have, but if not, test compression tomorrow along with your fuel pressure test.

Your ignition timing is spot on isn't it?

a4runnerfreak

Have you checked your cold start injector, the wiring going to the csi? What 'bout the csi time switch? Maybe clogged fuel lines, you sure your getting the right amount of fuel thru the rails?

ictyotafan

I got the fuel pump changed out today and no luck yet. This weekend I will go over a4runnerfreak's suggestions and hope to have some luck.

yayfortrees

Be careful relying on luck to fix a vehicle. I wish I had the money to throw on parts like you! My truck would be ready to go by now if I did!

abecedarian

Jumper battery voltage to the Fp terminal and see if it keeps running after you start it.

yayfortrees

Another guy's thread that I have been following finally came up with a definitive answer to his problem. He checked the compression and found 2 cylinders with problems, just like I suggested first. I hate it when that is the case, but proper diagnosis will save a lot of time and money.

Please, please, please rule out the motor by checking compression.

ictyotafan

I finally found my problem. The wiring harness that goes to the coil and ignitor had fell down on the headers and made an ugly mess. I got all this fixed and it is finally running again. Thanks for all of the suggestions.

Kiroshu

Did you try and spray carb cleaner into a hose going to the intake and see if will stay running? Thats the first step you take into finding out its a fuel prob. Possible signal problem. Check and clean all grounds and make sure they are where they are supose to be.

camo31_10.50

good suggestion Kiroshu..but i'm pretty sure he's figured out the problem

Kiroshu

lol wow i musta posted that as soon as he posted his cause i didn't see that lol.... That happens all the time where those signal wires from the ignitor get damaged and cause no start....