Hard starting change glowplugs now runs rough and sluggish
I have been having trouble stating 01 ford 7.3L diesel so i replaced glow plugs and relay. now starts right up but runs really rough it wont get up and go like it did before i changed them i checked electical wires that i took off and alson checked vacuume lines. what now. can a dealer hook it up to a computer and tell what is wrong like which cylinder is misfiring.
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Re: hard starting change glowplugs now runs rough and...
Well first off i would change the fuel filter if that has not been done also check the air filter if this does not work sounds like ya got a bad injector most any shop that works on diesel and has a scan tool can tell you what clynder is causing you the problem. They are a bullet proof engine most the problems i see are fuel leaks glow plugs and the relay that go bad but the injectors also go bad every now and then.
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Hard starts, can be a number of different things...
But most common is some or most of your glow plugs are bad, or your glow plug relay.
if you have not changed to glow plugs, in a few years, you should just replace them. They're not that expensive.
when glow plugs, and the relay are working properly, vehicle starts right up.
This is not to hard to solve. The outside airtemp determines how long the Glowplug timer works for absolute cold starts. Starting a warm engine is affected by underhood temps.
The Timer Relay will pulse power to the glowplugs. If the glowplugs are good, it is enough to preheat the cylinder for firing.
To tell if a glowplug is good is a matter of comparision between a new glowplug and a worn glowplug. YOU CAN MELT A GLOWPLUG WITH THIS TEST, but you remove the glowplugs, get a set of battery jumper cables and place one jumper to the base of the glowplug USING CARE not to ruin the threads on the glowplug.
You do not want to arc the spark on the glowplug threads. You want your fixed jumper connector locked on the base of the glowplug. The other battery cable jumper is touched to the top of the glowplug where the arcing occurs. This will not hurt the contact point if done properly.
You compare the "glow" of the old glowplug to the "glow" of the new glowplug. Bad glowplugs stay dark or operate at a darker color.
The Timer Relay gives you pulses and that is all the glowplugs get to heat up. This is what you simulate in your test. If a glowplug operates in a dull or dark condition, it is bad and throw it away. You want all glowplugs to readily light up when power is applied.
The other 2 parts to the system are the Timer Relay and the Power Relay. The timer gets its power from the Power Relay and the Power Relay is like a starter solenoid. The Power relay gets a tickler charge when the keyswitch is held to Start.
There are sometimes extreme cold Timers that hold the power longer tothe glowplugs. I do not have the Specs to tell you if your Timer is kicking out to soon.
I hope my solution helps. I have told you how to test your glowplugs. The timers are affected by air temperature and that makes it difficult to say if it is working long enough. If you know the glowplugs are good, and the timer shuts off before the glowplugs heat up, then you need a new or different type of timer.
Hello, The diesel engine relies on Glowplugs for the first start in the Morning or a cold start at anytime.
The Glowplugs themselves can be bad, but there is a Timer which determines how long the Glowplugs will stay on. Before the Timer is a Glowplug Relay which gives the Timer its power to operate. The Ignition switch provides power to the Glowplug Relay.
You disconnect a Glowplug wire, put on a test instrument (either a testlight or Voltmeter) and look to see what happens when you initiate a start. If the testlight lights and cycles a few times like a pulse, then the power supply is good. If not inspect the Timer and Glowplug Relay for continuity
If all the pulses seem to reach the Glowplugs, then most likely the Glowplugs are worn out. Test by removing then and connecting battery jumpers. Briefly touch the top terminal of the Glowplug with the Hot cable after grounding the negative cable on the base of the Glowplug, avoiding the threads.
You can melt a Glowplug. But if you find the Glowplug staying dark, then it is bad. Do this for all the Glowplugs and replace the bad ones. Remember the Glowplug only has the amount of time the Timer gives it to work. So if a few pulses do not make it Glow, then replace it. This should fix you up.
Check for fuses first. The Glowplug timer is the proper name for the part that responds to Temperature when starting your engine. When the engine is cold, of course it is on longer and can cycle making a click and intermittently dimming the lights on your truck. When the engine is warm, your gowplugs may not even fire as the engine is using compression alone to fire up.
Also, Ford did make a Severe Weather model that kept the glowplugs on longer. If you stay in Alaska or a climate with consistent subzero temperatures you may need it.
It sounds like your Glowplug timer or the Glowplugs are bad. The reason that turning the Key 4 or 5 times helps, is that everytime you put the Key to RUN or START you are energizing the Glowplug timer and reheating the Glowplugs.
You can check the Glowplugs by removing them and remove at least 1 bank at a time. Get some jumper cables and put the NEG post on the plug without smashing the threads. Take the POS cable and touch the Glowplug till it starts to Glow. You can mess up and melt the Glowplug so watch it. BUT, as you test you will find the bad Glowplugs will not light or will take longer to light up.
This is the reason I said to take out 4 plugs at a time, minimum, because you need to compare bad and good, visually.
The timer is not as easy to test. It is a variable timer and the warmer an engine is, the less time it will work. Obviously if the Glowplugs are not Hot, the timer is cutting off too early. But you check your Glowplugs first. The Glowplugs help to give a Feedback loop which tells the timer to stay on.
The rough idle is because the glowplug is not hot or the compression is bad in the cylinder.
some of the glow plug have had it, rough idle ,andsmoking after a hard start is typical symptom of some of the glow plugs not working.what happens then,is because you keep trying to start it,the remaining glowplugs get over heated with continuous heating up so they toss it in then it gets to the point where it wont start squirt some starter fluid ,or aerostart into th air cleaner and you will probablyfind it will start strait away if so anew set of glow plugs is in order ----"youdoit"
Check the glow plug relay, wires and glow plugs, could be that or an injector stiction problem. If you have an in range coolant sensor, intake air, or manifold air temperature fault the engine could think it is already warm when it starts and does not compensate for the cold start condition, however this is pretty rare anymore. If you need help with the glowplugs let me know.The stiction problem is going to require dealer tools unless you have a high dollar tool like a genisys which can do a scuff test and the knowladge of how to take the info to figure that the injectors are sticking. If you have a scan tool you can also look at all the temp sensors at start up to see if they are all normal.
Suspect the glow plugs or timer not working proper. You could plug your truck in keep the engine warm so it starts easier. Or you could have the glow plugs tested and replaced if faulty. Your engine has 8 glowplugs and even a couple faulty glowplugs will cause problems starting. You could have injector or injection pump problems as well but harder to diagnos yourself.