Confused grid warmers

[TFucili]

When I got my truck a few weeks ago, daytime temps were running in the high thirties to low forties, the grid warmer wait light would go out very quickly(probably <five seconds), and the truck would start at the very touch of the key, like a jerk pump. Over the last few days I have noticed on several occasions, with temps in the sixties, the wait light staying on much longer(maybe ten seconds), and the idle speed varying noticibly as the warmers continued to cycle. Additionally, even when the wait light goes out quickly it takes a few revolutions for the engine to fire now. Not prolonged cranking, by any means, but different than initially.



Opinions?

 

[TFucili]

Holy smokes, three quarters of my post didn't show up!!!

At the rate I type it'll take a week to re-do it. LOL

 

[TFucili]

Try, try again...

When I got my truck a few weeks ago daytime temps were running in the high thirties to low forties, the grid warmer wait light would go out very quickly(probably<five seconds), and the truck would start at the very touch of the key, like a jerk pump. Over the last few days I have noticed on several occasions, with temps in the sixties, the wait light staying on much longer(maybe ten seconds), and the idle speed varying noticeably(maybe three hundred RPM) as the grid warmers continued to cycle. Additionally, even when the wait light goes out quickly it takes a few revolutions for the engine to fire now. Not prolonged cranking by any means, but different than at first.



Opinions?



ARRRRRRRRRRRRRRRRRRGH!! It happened again, I surrender.

 

[p-Bar]

In 50 degree weather mine stays on for at least 10 seconds

 

[TFucili]

Well, what I tried to say was when it was cooler ambient the wait light was on <5 seconds and the engine would start instantly. Lately, at substantially warmer ambient, the wait light has stayed on substantially longer and it's taking several revolutions for the engine to fire. Not prolonged cranking, mind you, but discernably longer.

 

[RMalone]

My wait light stays on at least 10 seconds at 50f if the truck has sat for a long time. But at 50 if I start it again within 2 hours of it running the wait light goes off after its initial test cycle to show you all the lights work. It could be your engine just hasn't cooled off before you start it again. My truck always takes a few revolutions to start always has, funny my dads first gen truck starts as soon as the key hits start... go figure.

 

[TFucili]

It's not so much the particular things that the truck does bother me, but that a CHANGE in behavior,all else being equal is usually a signal. I've owned and worked on plenty of diesels, but they were all mechanical. Electronics are wonderful... when they work...

 

[Wayne M.]

Quote, My truck always takes a few revolutions to start always has, funny my dads first gen truck starts as soon as the key hits start... go figure.



Rmalone, the fact that the new trucks crank longer is not cause for concern. The older "mechanical" engines could start in a 1/4 revolution of the crank because the injection pumps were ready to spray fuel at a split second. Our newer "electronic" engines need about 2 crank revolutions for the computer to pick up on when cylinder #1 can fire, and then sets off a sequence of events to make the engine run.

In regards to the grid heaters, I really havent noticed a pattern as to how long they preheat accoding to ambient temp, I only care that they are working. The thing I noticed that is way different from my 'ol '92 is that they like to keep working for a long time afterwards (you can watch this via the voltmeter). What bugs me is that once the engine is warmed up, and you shut down for a minute, the grids heat on restart- no matter how long the tngine was off- even for just a minute. I once ran for an hour, shut down for fuel, and the voltmeter was doing it's dance (indicating grid action) on restart. I'm thinking this is for emmissions. The '92 I has would never heat the grids once the engine was running for the day, unless it was real cold out.

 

[RMalone]

Wayne M. my truck also runs the heaters (noticed via the voltmeter) the same way yours does. Kind of silly. Do you know?, does the wait to start light have to do with grid heaters or are they for a hot surface for ignition in cold starts. My voltmeter shows heater no matter how long the truck was run before being shut off in cold abient temps and restarted. However my wait to start light goes off with all the other dash lights if the truck is good and warm before you start it (independent of abient temps) just curious?

 

[Wayne M.]

I think the wait to start lamp (the curls) does light up like the other lamps (this is called "proving out" to show operation) and if it stays on, like the check engine lamp will (until cranked) the grids are definetly warming up. I think the voltage is cut when the lamp goes out, and then they heat again once the engine starts, and then goes into a cycle. The only hot surface in these engines (starting aid) is the grid heater, and the block heater, which is a different matter. There are no other aids like junky glowplugs. If the light goes right out, should if it's warmer than 50* ambient, then the grids shouldn't cycle.

 

[djr99]

The grid heaters cycle on and off after start (even hot restart). I believe this is to minimize the amount of smoke. I don't know what criteria the computer uses to shut them off. They shut off when you get above 20 mph anyway. It can be very annoying at night because the headlights (not very good to begin with) keep dimming.

 

[chessie-system]

The grid heaters are an emmissions related item that are required for the trucks. They get rid of most startup smoke but are not really necessary to get the truck to run as is Ford. I unplugged mine as soon as it came home from the dealer. I ran my 95 without them for 8 years. My 03 starts at 0 degrees no problem. The batteries lasted 6 years on the 95. I expect the same from the 03.

Jeff

 

[TFucili]

The engine will probably start without them, and there is surely an emissions benefit with their use, but, nevertheless, grid warmers, glow plugs, and ether injection are ALL termed "cold start aids".