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Hard starting

bdemutis

Active Member
Messages
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My truck I noticed is harder starting in the morning or after it sits. It dosnt always do this but sometimes. Anyway went to leave work after truck sat glow plugs cycle truck fires up and stalled then cranked and cranked gave it throttle and it roared to life allot of white smoke smells like diesel then clears up. Also I never hear the lift pump run after I turn the truck off I never tested the pump either I might just replace it tomorrow because I only hear it run when it's in drive and I prime the system.

I was going to install injectors but don't want to throw money at it.

New fuel filter, glow plugs newer pmd , gas cap, new bwd oil pressure sensor and both coolant temp sensors by bwd. glow plug light comes on what seems a long time.
 
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Sounds like air in fuel lines to me, possibly bad glows, or a combination. Someone correct me if wrong, but a weak injector will white smoke continuously?

Test lift pump by jumping the aldl. Lift pump wont run if you don't have oil pressure, assuming you have a non modified factory set up.

Make sure there are no fuel leaks anywhere. If you recently changed fuel filter check for fuel weeping around bottom of filter housing. The fuel heater on the bottom is a known leak area, particularly on 20 year old rigs.

It can run fine, until it sits for a while and the very minor leak allows the system to de pressurize and seep air in. You're looking for a very small leak.
 
Sounds like air in fuel lines to me, possibly bad glows, or a combination. Someone correct me if wrong, but a weak injector will white smoke continuously?

Test lift pump by jumping the aldl. Lift pump wont run if you don't have oil pressure, assuming you have a non modified factory set up.

Make sure there are no fuel leaks anywhere. If you recently changed fuel filter check for fuel weeping around bottom of filter housing. The fuel heater on the bottom is a known leak area, particularly on 20 year old rigs.

It can run fine, until it sits for a while and the very minor leak allows the system to de pressurize and seep air in. You're looking for a very small leak.
Brand new glow plugs I still haven't did the clear fuel line yet I havent even looked were to put the clear line yet I did change the filter because it was leaking a bit. I have no idea where it could be weeping.
 
Get some brake cleaner, spray down the filter housing, and suspect areas so no fuel is present, and everything is clean and dry. Come back a couple hours later and locate the leak. If your filter housing is in stock position on back of intake it's real hard to see what's going on at the bottom where the fuel heater element threads in(from the bottom up). The gasket can go bad there, and the seal where the wires go into the side of the heater are known leak areas. Less prone to leaks, but still a maybe, is the WIF sensor on the side of the housing. There's an O ring under there that can go bad.

I replaced my heater about three years ago. The new one was about $70.00 IIRC.
 
Get some brake cleaner, spray down the filter housing, and suspect areas so no fuel is present, and everything is clean and dry. Come back a couple hours later and locate the leak. If your filter housing is in stock position on back of intake it's real hard to see what's going on at the bottom where the fuel heater element threads in(from the bottom up). The gasket can go bad there, and the seal where the wires go into the side of the heater are known leak areas. Less prone to leaks, but still a maybe, is the WIF sensor on the side of the housing. There's an O ring under there that can go bad.

I replaced my heater about three years ago. The new one was about $70.00 IIRC.
Do you really need the heater or can I bypass it and I felt around the filter haven't had any more leaking and if the filter was leaking would it cause hard staring honestly it just randomly started.
Also is there a rebuild kit for it?
 
What is your cranking speed?

If you know of a leak, fix it. If you are leaking out fuel, you can suck in air at that location.

Remember you can suck in air without fuel leaking out.
You need the clear line. It's like $5. It replaces one on the front, top of the injector pump. It is a 1/4" line about 5" long it connects to a metal line that goes to both side of the engine and all the little 1/8 injector return lines connects together, then to the metal line.

Once you have eliminated the air possibility, then exam glow plug operation. What glow plugs did you install? Time the glow cycle- how long?
 
What is your cranking speed?

If you know of a leak, fix it. If you are leaking out fuel, you can suck in air at that location.

Remember you can suck in air without fuel leaking out.
You need the clear line. It's like $5. It replaces one on the front, top of the injector pump. It is a 1/4" line about 5" long it connects to a metal line that goes to both side of the engine and all the little 1/8 injector return lines connects together, then to the metal line.

Once you have eliminated the air possibility, then exam glow plug operation. What glow plugs did you install? Time the glow cycle- how long?
Ac delco glow plugs all 8 brand new. Glow plug cycle time I want to say it seems like the light stays on for a minute it feels like I'll time it tomorrow.
 
Rebuild kit is a new part. You can unplug the harness, but the part that leaks is on the side of the heater itself. If you remove the heater, you'll have about a 3/8" hole in the bottom of the filter housing. There's NO living without the heater.

If the housing itself isn't weeping anywhere, you have to start moving downstream. First the fuel supply line from the tank forward. The rubber sections there are likely 20 years old also. Look for moisture. Then the return line, the narrower line that runs parralel to the supply line along the frame.

If you jump the aldl to get the lift pump to run, you can crack open the bleeder on top of the filter, see if there is any air there. Probably not much if so. If you had a lot of air, you wouldn't get it to start. If you let the truck sit for a few days, you might have enough air that you'd have a no start.
 
Rebuild kit is a new part. You can unplug the harness, but the part that leaks is on the side of the heater itself. If you remove the heater, you'll have about a 3/8" hole in the bottom of the filter housing. There's NO living without the heater.

If the housing itself isn't weeping anywhere, you have to start moving downstream. First the fuel supply line from the tank forward. The rubber sections there are likely 20 years old also. Look for moisture. Then the return line, the narrower line that runs parralel to the supply line along the frame.

If you jump the aldl to get the lift pump to run, you can crack open the bleeder on top of the filter, see if there is any air there. Probably not much if so. If you had a lot of air, you wouldn't get it to start. If you let the truck sit for a few days, you might have enough air that you'd have a no start.
I let it sit usually fir two days over the weekend and she fires up that's what confuses me like today when I left for work fired right up leaving work she fought me maybe it's the pmd but I'd hate to change it with my new one maybe the pmd cable I heard they can go bad because I was having a problem where it would only go to 2500 rpms I unplugged it and plugged it in and she ran great.
Everytime I want to start doing upgrades or maintenance a new problem emerges lol.
 
Are you in road salt country? Perhaps a pin hole rusted in one of the steel sections of fuel line?

Is your relocated PMD on a heat sink, and is it secured in place, i.e. not just sliding around inside the bumper nostril. Fuel solenoid (PMD) problems can manifest all sorts of troubles. I was having weird troubles until one day the truck just died and stayed that way. The extension cable at the PMD in the bumper had finally chafed thru and one of the wires grounded to the inside of the bumper.......blew the "FSOL" fuse under the dash

Have you checked your grounds lately?, pull the FSOL fuse and clean the spades off?

All that being said, I still think it sounds like air from a bad fuel line or filter housing component.
 
Are you in road salt country? Perhaps a pin hole rusted in one of the steel sections of fuel line?

Is your relocated PMD on a heat sink, and is it secured in place, i.e. not just sliding around inside the bumper nostril. Fuel solenoid (PMD) problems can manifest all sorts of troubles. I was having weird troubles until one day the truck just died and stayed that way. The extension cable at the PMD in the bumper had finally chafed thru and one of the wires grounded to the inside of the bumper.......blew the "FSOL" fuse under the dash

Have you checked your grounds lately?, pull the FSOL fuse and clean the spades off?

All that being said, I still think it sounds like air from a bad fuel line or filter housing component.
Yes the pmd is securely mounted under the bumper on a heat sink.
I'm in pa so I guess you can say I'm in salt country. Most the time I thought if the fuel bowl was leaking it would run down the back of the motor and drip all over the ground or trans.
 
Ok so the wait to start stayed on 7 seconds the truck took a few cranks to fire up two key turns. So I'll prime it before I leave work in drive and see if she fires better I also checked the filter housing it's not leaking anymore and I checked in the valley around the filter it dosnt appear to be wet. Maybe I'll pull the intake off and check the lines running to the pump and from.
 
6 to 10 seconds is fairly normal for glow time. I've got fairly new glows and am in s Fl and mine typically will glow about 7-8ish.

If you don't know how miles are on your injectors, or you suspect it is over 100k or more, it couldn't hurt to pull them, and at least have 'em cleaned and tested. Then you'll know if the $$ to replace them are warranted. Those on the passenger side are tuff to get at.

A minor fuel leak in the engine valley may never make it to the ground. There's a small weep hole at the back of the block that drains into the bell. A minor leak will get thrown all over the inside of the bell by the flex plate, etc. A larger leak will be coming from the weep hole on bottom of transmission dust shield and sometimes mistaken for a leaking rear main.......But if everything is dry in the valley, the air may be coming from elsewhere.

Might check if all the injector lines are dry in the bevel on top of the connection nut. Corrosion and vibration have been known to loosen things up after a time.
 
6 to 10 seconds is fairly normal for glow time. I've got fairly new glows and am in s Fl and mine typically will glow about 7-8ish.

If you don't know how miles are on your injectors, or you suspect it is over 100k or more, it couldn't hurt to pull them, and at least have 'em cleaned and tested. Then you'll know if the $$ to replace them are warranted. Those on the passenger side are tuff to get at.

A minor fuel leak in the engine valley may never make it to the ground. There's a small weep hole at the back of the block that drains into the bell. A minor leak will get thrown all over the inside of the bell by the flex plate, etc. A larger leak will be coming from the weep hole on bottom of transmission dust shield and sometimes mistaken for a leaking rear main.......But if everything is dry in the valley, the air may be coming from elsewhere.

Might check if all the injector lines are dry in the bevel on top of the connection nut. Corrosion and vibration have been known to loosen things up after a time.
So make sure there all tight and dry hell I'll just get the new injectors I know they probably just hit 100k or more lol.
 
here's a video of her running I mean I don't know what a healthy 6.5 sounds like also the gunk in my cdr is condensation I light it on fire it sizzles.
 
Sounds pretty normal to me. Maybe a little bit of a slow idle. Maybe mine just idles a bit higher. Been six months since I've heard mine run at all.......

Clean the gunk out of your cdr, preferably NOT by burning it out.;) I use brake cleaner, some rinse them out with diesel fuel, or mineral spirits. The cdr isn't your start issue tho.......
 
I was having a problem where it would only go to 2500 rpms I unplugged it and plugged it in and she ran great.

Wiggle test FAILED! Did you replace the cable and PMD? STOP! You had a failure of the connector and plug in unplug isn't a cure it's a test procedure. Do both just to be sure and get the Made in USA version of the cable as the Cheap China ones do cause issues.

Park the truck nose down and see if it starts easier. Nose down reduces the fuel drainback to the tank. Lift pump failure causes hard starting.

As said above: Crank RPM is critical as well as glow plug time. 100 RPM minimum cold and 150 RPM hot.

Factory glow plug time is frankly too short for the "new" slow self limiting plugs. A tune can extend glow plug time and it should with self limiting plugs.
 
Saw in the video you have the IAT sensor tee'd with the boost gauge. The IAT must be in the boosted air stream and can affect timing and fueling negatively like you have it.
 
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