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Hello, so I have a 99 7.3 powerstroke that started to rev itself and run rough intermittently while driving and throwingan intermittent ses light.. I had had slight issues with truck reving itself In past so I replaced the tps. Truck now only acts up when cold upon start up and blows tons of white smoke and is hard starting.. ses light is on all the time as well. I tried reading codes but it says no codes (maybe due to truck being chipped). Also this all started happening immediately after I changed my fuel filter. Any help would be greatly appreciated as I need my truck to back and reliable. Thank you
Depending on if this is an early 99 or a late 99, you could have your glow plug relay or your intake air heater relay going bad. They are IDENTICAL components, and last I knew fairly cheap. The early '99 trucks did NOT have the intake air heater, the later ones did. I had an early '99 and lost the glow plug relay and could NOT get the truck to start. My FIL had a late '99 and his intake air heater relay went bad, and his would start but only if he either used the block heater for an hour OR put a salamander heater on it for a while. Even then, it would have a LOT of white, fuel-smelling smoke coming from the exhaust until the engine warmed up. We replaced the intake air heater relay and his hard starting issue went away.
No idea if this will solve your SES light, since you said it won't pull codes despite the light being on. Neither of our trucks threw codes for these two relays.
How are you pulling codes?
Parts store readers do not do well with our trucks. Get FORScan on your phone and the recommended OBD II reader. FORScan can do just about everything the Ford Dealer can do.
However as above unless something else is going on the relay going usually will not throw a code, but the relay is an easy check.
You can jump the terminals on a glow plug relay with a screwdriver. I did this for a week or so a few yrs ago until i was able to replace the relay. I would turn the key on, jump the solenoid by holding the screwdriver on the 2 terminals for 15-20 seconds. Jump in the truck quickly and fire it up.
When you replace the solenoid don't use a crap parts store or regular start solenoid. Get a trombetta or stancor upgraded relay. Or get a motorcraft.
You can jump the terminals on a glow plug relay with a screwdriver. I did this for a week or so a few yrs ago until i was able to replace the relay. I would turn the key on, jump the solenoid by holding the screwdriver on the 2 terminals for 15-20 seconds. Jump in the truck quickly and fire it up.
When you replace the solenoid don't use a crap parts store or regular start solenoid. Get a trombetta or stancor upgraded relay. Or get a motorcraft.
Yes, you can jumper over the solenoid with a screwdriver or something steel with a nice rubber/plastic handle on it. Had to do it many times myself. You're going to see a good spark though, so don't be to scared of it.
That said, 15-20 seconds seems a bit excessive...that length of time will burn up your glow plugs, since the computer only commands them on for 5-8 seconds MAX. Heck back in the 80's when my dad by passed the solenoid on his 6.2 GM diesel he would only hold it for a count to 5.
Depending on if this is an early 99 or a late 99, you could have your glow plug relay or your intake air heater relay going bad. They are IDENTICAL components, and last I knew fairly cheap. The early '99 trucks did NOT have the intake air heater, the later ones did. I had an early '99 and lost the glow plug relay and could NOT get the truck to start. My FIL had a late '99 and his intake air heater relay went bad, and his would start but only if he either used the block heater for an hour OR put a salamander heater on it for a while. Even then, it would have a LOT of white, fuel-smelling smoke coming from the exhaust until the engine warmed up. We replaced the intake air heater relay and his hard starting issue went away.
No idea if this will solve your SES light, since you said it won't pull codes despite the light being on. Neither of our trucks threw codes for these two relays.
thank you, I checked intake heater relay and it does appear to be bad, I had checked my glow plug relay but neglected to check the other. My truck is a late 99. I think I may have another issue though with the truck reving itself? Could it be the truck trying to find idle? I will see if the relay changes anything.
The air intake heater doesnt do much to help with cold starts. I think its actually designed to help prevent dry stacking during long idling. It takes alot of circumstances for it to actually turn on. Many 7.3 owners delete the aih and use this port for a boost guage fitting, including me.
15-20 seconds of glow plug is 1/4 of its standard run or on time. The pcm regulates it to 120seconds. Alot of guys will do 2 or 3 cycles when its real cold.
Could the high idle be engaging? Is this the high rev you are hearing? With low enough temps and during a long idle the motor will go into high idle.
Do you have a multi meter? You can easily check resistance to you injectors to check the uvch and wiring.
The air intake heater doesnt do much to help with cold starts. I think its actually designed to help prevent dry stacking during long idling. It takes alot of circumstances for it to actually turn on. Many 7.3 owners delete the aih and use this port for a boost guage fitting, including me.
I suggested it because my FIL had a late '99 that WOULD NOT START on a cool (sub-50°) morning unless he ran a salamander heater under it for 20 minutes, and even then it would crank for a long time just blowing white smoke before it would start and run. We replaced the Air Intake Heater relay and it would fire right up even below freezing with no issues.
Am I saying it is like that with all trucks? No. Just stating my experience.
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). Also this all started happening immediately after I changed my fuel filter. Any help would be greatly appreciated as I need my truck to back and reliable. Thank you
