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Hesitate when first entering the freeway, not choked correct

4cyl(YIKES!), V6 or V8 REPAIRS, ADJUSTMENTS, UPGRADES/MODIFICATIONS.
ANTYHING FROM AIR/OIL/FUEL FILTERS TO CRANK TURNING/BLOCK BORING, POST IT IN HERE
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LaGrasta
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Hesitate when first entering the freeway, not choked correct

Post by LaGrasta »

Something new has been happening these past few months, can't figure it out.

Background:
186k miles
fairly new rebuild on rear end and trans
tune up just a few years ago, maybe 30k or so


I start the van, jump on the freeway and I feel it cut on and off, hesitate, shudder, etc. If I engaged the cruise, I can really feel it. It goes away in less than a mile and doesn't do it again until it sits overnight upon first start up again. Once warm it never does it. After arriving to work and it sits at work all day, ti doesn't do it either.

Maybe a "choke" issue?
1998 Astro, 224,000 miles

K&N air filter
TruCool trans cooler
2" Overland lift & 15" BFG Terrain, 3.73 gears
JET Performance SCU-2000 (Speed Control Unit)
Gabriel Ultra shocks, rear AirLift bags & sway bar
iPOD, CD, DVD, Dutch door mounted 12s, 400w
Draw-Tite Dual Port Hitch System, hitch-mounted bike rack (4), hitch-mounted cargo tray, Thule roof-mounted cargo box

LiftedAWDAstro
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How many wheels are on an Astro van? (4): 6
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Re: Hesitate when first entering the freeway, not choked cor

Post by LiftedAWDAstro »

Well there is no choke on the fuel injected engines, but it does sound like an open/closed loop running issue. I am not real familiar with what sensors are used during open loop compared to closed loop so hopefully one of the more technical guys can help. Have you pulled any codes or pending codes yet?
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy
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LaGrasta
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How many wheels are on an Astro van? (4): 4
Location: Mission Viejo, CA

Re: Hesitate when first entering the freeway, not choked cor

Post by LaGrasta »

notice choke was in quotes, i wasn't sure what to call the process of "waring up" a FI. lol
no codes at all.
1998 Astro, 224,000 miles

K&N air filter
TruCool trans cooler
2" Overland lift & 15" BFG Terrain, 3.73 gears
JET Performance SCU-2000 (Speed Control Unit)
Gabriel Ultra shocks, rear AirLift bags & sway bar
iPOD, CD, DVD, Dutch door mounted 12s, 400w
Draw-Tite Dual Port Hitch System, hitch-mounted bike rack (4), hitch-mounted cargo tray, Thule roof-mounted cargo box

LiftedAWDAstro
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How many wheels are on an Astro van? (4): 6
Location: New Haven, NY

Re: Hesitate when first entering the freeway, not choked cor

Post by LiftedAWDAstro »

I figured being in quotes meant you knew there wasn't an actual choke. Wish I could help you with more troubleshooting ideas.
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy
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Topic author
LaGrasta
I sleep in my van
Posts: 715
Joined: Fri Jan 19, 2007 10:07 pm
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How many wheels are on an Astro van? (4): 4
Location: Mission Viejo, CA

Re: Hesitate when first entering the freeway, not choked cor

Post by LaGrasta »

At first I wondered if one of the rear bearings were dragging, they weren't replaced when i rebuilt the rear end. What killed that theory is it never does it unless it sits overnight. Hmmm.

Anyone else have any guesses?
1998 Astro, 224,000 miles

K&N air filter
TruCool trans cooler
2" Overland lift & 15" BFG Terrain, 3.73 gears
JET Performance SCU-2000 (Speed Control Unit)
Gabriel Ultra shocks, rear AirLift bags & sway bar
iPOD, CD, DVD, Dutch door mounted 12s, 400w
Draw-Tite Dual Port Hitch System, hitch-mounted bike rack (4), hitch-mounted cargo tray, Thule roof-mounted cargo box
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Smiliesafari
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How many wheels are on an Astro van? (4): 4
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Re: Hesitate when first entering the freeway, not choked cor

Post by Smiliesafari »

Run some "Seafoam" through it. Half can in the intake and the other half in the gas tank. It could be something as simple as dirty injectors.
1996 Safari SLX Hotair balloon transport vehicle

astrozam
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Re: Hesitate when first entering the freeway, not choked cor

Post by astrozam »

EGR valve perhaps? I'm not sure if the 98's were the same as the 95's but I remember having issues sort of similiar to that one time due to a sticky EGR valve...but I'm only takin a guess here.
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LaGrasta
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Re: Hesitate when first entering the freeway, not choked cor

Post by LaGrasta »

I have a new spider injector upgrade somewhat recent, but the EGR valve, hmmm. Let me gander that.
1998 Astro, 224,000 miles

K&N air filter
TruCool trans cooler
2" Overland lift & 15" BFG Terrain, 3.73 gears
JET Performance SCU-2000 (Speed Control Unit)
Gabriel Ultra shocks, rear AirLift bags & sway bar
iPOD, CD, DVD, Dutch door mounted 12s, 400w
Draw-Tite Dual Port Hitch System, hitch-mounted bike rack (4), hitch-mounted cargo tray, Thule roof-mounted cargo box
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v8famvan
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How many wheels are on an Astro van? (4): 4
Location: British Columbia

Re: Hesitate when first entering the freeway, not choked cor

Post by v8famvan »

CMP retard issue?
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Topic author
LaGrasta
I sleep in my van
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Joined: Fri Jan 19, 2007 10:07 pm
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How many wheels are on an Astro van? (4): 4
Location: Mission Viejo, CA

Re: Hesitate when first entering the freeway, not choked cor

Post by LaGrasta »

UPDATE: It turns out it was low on trans fluid
1998 Astro, 224,000 miles

K&N air filter
TruCool trans cooler
2" Overland lift & 15" BFG Terrain, 3.73 gears
JET Performance SCU-2000 (Speed Control Unit)
Gabriel Ultra shocks, rear AirLift bags & sway bar
iPOD, CD, DVD, Dutch door mounted 12s, 400w
Draw-Tite Dual Port Hitch System, hitch-mounted bike rack (4), hitch-mounted cargo tray, Thule roof-mounted cargo box
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okie1
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Re: Hesitate when first entering the freeway, not choked cor

Post by okie1 »

Thanks for coming back with the answer, might help someone down the road. :partyman:
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Topic author
LaGrasta
I sleep in my van
Posts: 715
Joined: Fri Jan 19, 2007 10:07 pm
antispam: No
How many wheels are on an Astro van? (4): 4
Location: Mission Viejo, CA

Re: Hesitate when first entering the freeway, not choked cor

Post by LaGrasta »

So many miles later, the problem returned and became worse. It bucks when idling along, such as when on cruise control on freeway. Basically, it's noticeable when no or little fuel is being supplied. With this determination, I finally figured it out and 100% fixed it. The distributor was worn and needed replaced. $100 and an hour of labor and it is back to perfect. This was a long term troubleshoot experience. We're now at 221,000.
1998 Astro, 224,000 miles

K&N air filter
TruCool trans cooler
2" Overland lift & 15" BFG Terrain, 3.73 gears
JET Performance SCU-2000 (Speed Control Unit)
Gabriel Ultra shocks, rear AirLift bags & sway bar
iPOD, CD, DVD, Dutch door mounted 12s, 400w
Draw-Tite Dual Port Hitch System, hitch-mounted bike rack (4), hitch-mounted cargo tray, Thule roof-mounted cargo box
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