Strong throttle "SURGE" at startup... - Diesel Forum

jlsworks · 09-10-2001, 03:21 PM

As of lately, my 12,000 mile SD experiences a strong throttle surge on startup. When I start the truck first thing in the morning, it will really throttle the motor, and then calms right down.
The truck usually starts strong, with plenty of body movement, but this morning it really hit the throttle hard, it sounded liked it "tweaked" the motor a little because it started so hard (I have experienced this 3-4 times now in the last month, cold motor only).
Can this be doing some damage to the motor getting the beast turned over first thing in the morning?
This seems uncharacteristic, Do any others start strong like this? Does the truck "move" on startup.

STROKER DUMP · 09-10-2001, 04:11 PM

My '01 also does that. I would say it revs up to around 1500 and then settles down. I don't like it any more than you do as this cannot be good for a cold motor with no oil pressure. I haven't had a chance to ask the service manager about it yet, as if he would know. LOL

F-250 Hoss · 09-10-2001, 04:36 PM

Mine revs at startup and then quickly idles back down, but I've always thought this was normal. I don't think I've ever had a vehicle that didn't do that.

Fritzmaster · 09-10-2001, 07:25 PM

Gets the pressure up FAST. I don't think it's harmfull, there is no load on the engine, and it get the oil flowing.

fredvon4 · 09-13-2001, 10:53 AM

I have only had the surge twice. Both times this week as I am going to work early(4:30 AM)to get into the three hour line on to Fort Hood (total security inspection of every auto).

I got the truck in April and it is now cooler in the AM then then.

The engine has always started instantly and this short surge bugged me both times. I am very consistent in my shut down proceedures as I flew in helicopters most of my career and have had several turbo autos.

On electronic controlled engines I never have my foot on the throttle as there is no accelerator pump (carburator) or choke plate to move anyway.

My point is, that the surge on my engine is NOT from an extra load of fuel in engine from previous shut down. Nor is it from throttle body butterfly plates being open by my foot.

Conclusion is that the computer is causing this surge for an unknown reason.

I am only concerned about this as the oil preasure has not gotten to the top end and this is not good.

I am interested in what others are experiancing and what different service managers claim to be the culprit.

I have a GOOD code, IWG0, and do not want FoMoCo changing it, as others have reported loss of power and MPG with "fixed codes"

your thoughts folks.

jlsworks · 09-13-2001, 11:18 AM

So, someone is experiencing the same thing, as far as I know I havent had any computer updates done. I really thought I've heard the motor "tweak" once or twice, have you experienced any strange grunts on startup?

F-250 Hoss · 09-13-2001, 01:29 PM

Just what kind of RPMs are we talking here? As I said earlier, my truck always kind of revs up when first started. I haven't checked, but I'd say it goes up to about 1500-1700 RPM from just thinking about it. How high does your go?

wldwilliam · 09-13-2001, 08:51 PM

Mine will go up as high as 2000. It's too high if you ask me and takes too long to settle in to a good idle position.

MECHANIC88115 · 09-13-2001, 11:00 PM

The v10's and 5.4's do that about the same as the 302 351, the 460 did it mildly, the 302 and 352 did the exact same thing, they would rev to about 2000 for a second or two, then come down to 1000 for the same amount of time, and then finally settle at the ideal speed of 750, I don't know about the 300 L6, it has been to long since I seen one. Hope this helps, mason

F-250 Hoss · 09-14-2001, 07:37 AM

I double checked last night. When first started, mine jumps up to the 1600-1700 range and then quickly settles down to idle at about 900-1000. It's done this since day one and it does it every time I crank up. Like I said before, I don't recall ever having a vehicle that didn't do something similar.

Is that what you're calling the surge or does yours do something different. Like someone said, my truck actually moves when the engine cranks, but I don't think there's a vehicle on the road that doesn't move a little bit (the bigger the engine the more the movement???).

CooperJ · 09-17-2001, 12:57 AM

My 2001 does the same thing. I'm sure it's the computer "priming" the injection and I'd be surprised if it did any harm...I also suspect that this is why the "starting drill" is not to touch the gas - because the computer does it for you.

Homegrown · 09-18-2001, 12:50 AM

I wouldn't get too excited about this, as mine revs to 1500, for a second or two and then settles at around 750. My 1986 with a 351 4 barrel carb had several steps on the choke plate cam, the first of which held the RPM's at 2200! until the motor warmed up a bit. According to the shop manual, this is exactly the way it was supposed to work. Hard to argue with them since the motor had 165K on it (when I sold it), good compression, and never had the heads off. [img]images/icons/smile.gif[/img]