Extreme Trouble Cranking 7.3 IDI

[TomQ83]

Hello Everybody, I have been looking through the forum and I can't seem to peg the problem I've run into. I started having real hard times getting the truck to crank. It is a 7.3 IDI turbo. Sometimes warm it would start right up, sometimes it wouldn't. I noticed that my fuel fitler, upon removal is only half full. I found a broken cap in the return lines, and got the kit from napa to replace it. I tried to crank again, and even drove it around the block. I let it sit and cool for a couple of hours, and again it won't crank, and again the fuel filter is half empty (or half full for the positive people, hehe). I replaced the injectors, thinking that I had one hung that was bleeding off. When looking at the old ones, half of them were clogged. Now, after replacing the injectors, I can get the truck to crank after about 3 or 4 minutes, but it only runs for about 10 seconds, and then runs out of fuel. I keep finding these little problems here and there, and it's driving me insane because I've not fixed the main problem. Am I looking at a bad lift pump? That's not keeping the filter full enough to feed the injector pump?

 

[icanfixall]

Well it sounds like your not getting fuel to the filter. So what you need to do is press that schrader valve when the engine is cranking. See if air or fuel comes out. The schrader valve is the inner tube looking thing on the fitler head. Now please answer this.. When you say can't get it to crank.. Are you telling us the starter wont crank the engine or the engine cranks but it wont fire up. So we need to know this before we can go much farther. Now another question about the injecters. Where did you buy them and are they new or rebuilt. What codes are they also. Whenever you replace injecters it best to replace the complete return line kit. Not just spome of them. When you say some of the injecters were plugged.. What makes you think that. All injecters have a needle called the pintle that sticks out the hole in the nozzle. Fuel will get under the pintle and lift it out of the nozzle..

 

[TomQ83]

Icanfixall, Thank you for your response. The injectors had crud built up under the brass ring. I took a pick and scraped around and got it all off, but I was afraid that same crud was built up in the injectors. I got the injectors from O'reilly's as they were the only ones that had 8 in stock. They were BWD Remanufactured injectors. I replaced all 8 caps, and all of the lines between them, used all new line and connectors. The truck will crank over, but will not start. When I finally do get it to pop off, it'll only run for about 10-15 seconds. I will get someone tomorrow to hold open the schrader valve while I'm cranking to see if fuel is coming out there. After replacing the injectors, I did crack all the lines and turn it over until I saw fuel coming out of each injector.

 

[riotwarrior]

Icanfixall, Thank you for your response. The injectors had crud built up under the brass ring. I took a pick and scraped around and got it all off, but I was afraid that same crud was built up in the injectors. I got the injectors from O'reilly's as they were the only ones that had 8 in stock. They were BWD Remanufactured injectors. I replaced all 8 caps, and all of the lines between them, used all new line and connectors. The truck will crank over, but will not start. When I finally do get it to pop off, it'll only run for about 10-15 seconds. I will get someone tomorrow to hold open the schrader valve while I'm cranking to see if fuel is coming out there. After replacing the injectors, I did crack all the lines and turn it over until I saw fuel coming out of each injector.

Welcome to OB, I assure you this has been covered very thoroughly here in many many threads. Lets just pick up where you are for now.

Please also peruse the FAQ and tech sections along with the hall of shame...KEEP YER HARD EARNED MONEY..don't give it to bad retailers!

SO lets start with some basics...

Now what level is yer fuel at in the tank?

If it's 1/4 tank or less you may have a broken shower head. That's a common problem with a relatively simple fix. For now top up the tank with a Gerry can 5 gallons if it's at 1/4 tank. that will suffice.

Ok so if you know how to bypass your ign solenoid on the fender, you can just as easily do this yourself, leave the key off...crank the engine over and hold the schrader valve in watching for air/fuel.

You say you replaced the caps lines and O rings, did you by chance replace the bottom o rings first? Or did you install the top most o rings then roll the bottom ones down over the uppers? This makes a difference. Please elaborate.

Did you replace all the return line caps? The Turbo model has a special T cap or two, most kits don't have those, please explain.

Did you replace ALL the return line and clamps?

Just trying to fish for details before making suggestions, the more information and details you can provide, the better we can help.

Anyway, Welcome to OB

Al

 

[TomQ83]

Hello Al, thank you for your response. The kit I got from napa had all of the caps that snap o er the injectors. It did not have the T fitting that was on the back of the engine. I replaced the line from injector pump, all the way down the left side of the engine, the two pieces across the back of the engine, the lines down the right side of the engine and up to the water/fuel separator. The new injectors came with the O rings already installed, so I honestly cant say how they were put on. I didnt even think of jumping out the solenoid, i know we have a switch to do just that in our tool box. I am going to see how much fuel comes out today when I get off work.

 

[OLDBULL8]

To set the record straight, you don't have trouble "CRANKING" , you have trouble "STARTING".

Am I looking at a bad lift pump? That's not keeping the filter full enough to feed the injector pump?

Yes, more than likely.

Since the fuel filter is half full after starting and running for 10 seconds as you say. By cranking your filling the filter and fuel line to the IP enough to run the engine for the 10 seconds, the IP will suck fuel until it empties the filter half way, that means the lift pump is not supplying fuel into the filter. That means either your lift pump is bad, your tank is empty, tank is less than 1/4 full and the tank suction shower head is broke off. Check your engine oil level, if the lift pump diaphram is broke, you will pump fuel into the crankcase. If replacing the lift pump, make sure the arm goes under the cam.

I can get the truck to crank after about 3 or 4 minutes, but it only runs for about 10 seconds, and then runs out of fuel.

Don't crank for more than 20 seconds without letting the starter cool off for 2 minutes between cranks. You will burn the starter up.

The injectors had crud built up under the brass ring. I took a pick and scraped around and got it all off, but I was afraid that same crud was built up in the injectors

Scraping the injector seat with a pick is a NO NO, you can scratch the seat and the copper washer may not seal and you will get even more carbon there after you get it running, torque the injectors to at least 35 ft lbs. To clean the seats, get a 12 guage shot gun brass brush.
Hopefully you lubed the o'rings before installing the caps, if not, it's possible to cut the o'ring and allow air intrusion.

 

[riotwarrior]

......Hopefully you lubed the o'rings before installing the caps, if not, it's possible to cut the o'ring and allow air intrusion.....

This is a good point as well as removing any parting/casting flash carefully prior to installation.

Guess we shoulda mentioned that...rofl

 

[TomQ83]

You are correct, I was having trouble starting the engine, have no trouble cranking it. I definitely was only cranking for about 20- 30 seconds at a time with a break in between cranks. Partially to give the starter a break, and to recharge the battery. I did lube the rings before putting the caps on, I don't want to have to go buy a kit for one O ring. I am going to pick up a lift pump on the way home today, and we'll see how it plays out. Again, I appreciate the patience and help.

 

[riotwarrior]

You may find that a nice DURALIFT from Genlightening would be the way to go. Take a gander at the Tech articles for a Duralift pump install...and you'll see just how impressive it is. Makes priming a breeze too BTW

JM2CW

Al

 

[icanfixall]

The electric lift pump is the best way for these engines to prime the fuel systems and keep them running. We don't have to crank the engine to fill the filter after a replacement. Just turn on the ignition key and wait for it... Be careful installing the arm on the new lift pump. It has to be placed on top of the cam lobe. If it gets under the cam it will break off and end up in the oil pan.. Thats not a bad place but its not where it belongs either.

 

[OLDBULL8]

The electric lift pump is the best way for these engines to prime the fuel systems and keep them running. We don't have to crank the engine to fill the filter after a replacement. Just turn on the ignition key and wait for it... Be careful installing the arm on the new lift pump. It has to be placed on top of the cam lobe. If it gets under the cam it will break off and end up in the oil pan.. Thats not a bad place but its not where it belongs either.

Gary; Sorry to disagree with you. The arm definetly has to go under the cam lobe. But I'm sure he will read the instruction's.

1st pic is an airtex, that can go straight in. 2nd pic is a Carter, that has to tip up to go under the cam lobe.

 

[TomQ83]

Well the lift pump wasn't it. I primed it, it cranked immediately, ran for 10 seconds, and shut down. The return lines are empty and the fuel filter is once again half full. I'm at a complete loss.

 

[icanfixall]

What the hell was I thinking.. Arm on top of the cam... How imbarrassing that one is... Well I guess I am human after all... Thanks Bill... I sure would have felt horrible if someone did that and it ruined a good pump...

 

[gatorman21218]

start replacing the rubber fuel line with clear tubing to see if you are getting fuel and if there are bubbles in it. this is my go to way of discovering air leaks. Start with the short piece feeding the lift pump

 

[TomQ83]

Alright, the fuel filter housing is cracked. anybody have a part number for it? I can't seem to find it anywhere. Thanks!