Start Up Surge
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Mountain Pass
Joined: Dec 2003
Posts: 168
Likes: 0
From: NJ
Start Up Surge
My 97 always has what I call a surge, then drop in rpm, then surge, then drop in rpm at start up in the morning. The best I can describe it is, it sounds like it goes vrumm, vrumm. Does this about 4 or 5 times then runs fine. Is this due to air in my fuel line?
lost
Joined: Apr 2003
Posts: 290
Likes: 0
From: Worland, WY
That is the glow plugs kicking in and out. It is normal. It is a on/off surge of the electrical system (GPs) causing the engine rpm to vary due to the increased strain on the alternator.
Last edited by Chris56ford; Nov 27, 2011 at 10:52 AM. Reason: ...
Senior User
Joined: Jul 2009
Posts: 476
Likes: 0
From: Bellingham, WA
Is It a "rough" surge?one of my trucks does what your describing but some what violent... I'm going to pull the crappy chip it came with one day and see if that is it for some reason, but I thinking I'll try to throw a eot sensor at it as this also effects start up... Just a thought and subscription!
Elder User
Joined: Aug 2009
Posts: 869
Likes: 1
From: Michigan
I suspected that wasnt the case. the volt meter stays down well beyond the 1 or 2 second romp romp right at startup that im getting.
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Post Fiend
Joined: Dec 2010
Posts: 10,121
Likes: 3
From: Orrville, Ohio
FWIW, The engine I just swapped into my truck was doing this in the truck it came out of. When I had it on the engine stand, I did quite a few things to it, but the only one I think could have affected this issue was that I replaced the IPR o-rings. Now in the new truck, it doesn't surge or romp at all. I have heard that this surge can be caused by the IPR stroking wildly trying to control ICP. Not 100% positive that the IPR o-rings are what solved it for me, but it might be worth a try.
Oh, and 2x on doubting that it is being caused by the GP's.
Oh, and 2x on doubting that it is being caused by the GP's.
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Post Fiend
Joined: Dec 2010
Posts: 10,121
Likes: 3
From: Orrville, Ohio
Not saying that's not the OP's issue but my donor truck was a ZF5 and mine is an E4OD, so that wasn't the issue for me. Not sure if this post was directed to me or the OP...
Hotshot
Joined: Aug 2006
Posts: 10,764
Likes: 39
Just to anyone it may apply to. Surge at start up means the PCM is confused by the info its getting ..Leaking or bad ICP sensor , of bad connection may also be the case ...
lost
Joined: Apr 2003
Posts: 290
Likes: 0
From: Worland, WY
Reason I talk about the GPs is, mine does this when its cold, like 15 degrees. When I start my truck, the GPs run for a short time as shown by my volt gauge reading like 10 volts.
Then a few moments later as I watch the volt gauge and RPMs I see it surge up and down about 100-200 rpms and the volt gauge also goes up and down (10v-14v) with the rpm. This lasts only for a few moments and the GP system turns off and the rpms stop surging and the volt gauge reads the normal 14v.
It may not necessarily be the GPs themselves, but something with GP system, maybe with the PCM or another sensor.
If my truck is plugged in or its warm, I haven't seen it do it. Just my $.02.
Then a few moments later as I watch the volt gauge and RPMs I see it surge up and down about 100-200 rpms and the volt gauge also goes up and down (10v-14v) with the rpm. This lasts only for a few moments and the GP system turns off and the rpms stop surging and the volt gauge reads the normal 14v.
It may not necessarily be the GPs themselves, but something with GP system, maybe with the PCM or another sensor.
If my truck is plugged in or its warm, I haven't seen it do it. Just my $.02.
Elder User
Joined: Aug 2009
Posts: 869
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From: Michigan
Lead Driver
Joined: Oct 2003
Posts: 8,476
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From: Madison, WI
But in the OP's case, if it's only romping 4-5 times, it's probably not this anyway. Sounds more like a fuel pressure / HP oil pressure thing. Might be worth checking the level of the HPOP reservoir and/or the fuel bowl before a startup sometime.
Hotshot
Joined: Aug 2006
Posts: 10,764
Likes: 39
If it is truly the "romps" at start up it is usually an electrical signal issue . May be due to the ICP sensor or wire as I said , or a slow to respond IPR also .. The PCM can't see fuel pressure . SLow up and down idle can be from something as simple as a plugged FPR screen ...