Last post on Oct 17, 2006 at 8:12 PM
You are in the Chevrolet S-10 & GMC S15 Sonoma
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Chevrolet S-10, GMC Sonoma, GMC S-15, Truck
#571 of 2018 Re: 95 chevy s10 one of the 20,000 [collegej82]
Mar 22, 2005 (8:45 am)
Maybe this can help ???
Fuel System - MIL ON/Rough Idle on Start-Up
File In Section: 06 - Engine/Propulsion System
Bulletin No.: 00-06-04-003B
Date: February, 2003
Rough Idle After Start, And/Or A Service Engine Soon (SES) Light
(Unstick And Clean Central Sequential Fuel Injection (CSFI) Poppet
Valves or Convert to MFI)
1995-2002 Chevrolet and GMC S/T Models
1996-2002 Chevrolet and GMC C/K, M/L, G, P Models
1996-2001 Oldsmobile Bravada
1999-2000 Cadillac Escalade
with 4.3L, 5.0L or 5.7L Engine (VINS W, X, M, R - RPOs L35, LF6, L30, L31)
Except 2002 VIN X - RPO LU3 Models
This bulletin is being revised to update the Warranty Information. Please discard previous copies of Corporate Bulletin Number 00-06-04-003B with warranty chart (Section 06 - Engine). This copy is for Dealers in the state of CALIFORNIA ONLY.
Some customers may comment on rough idle after start-up, especially if the vehicle has sat overnight. These symptoms may be intermittent. The Service Engine Soon (SES) light may also be illuminated. Current misfire or history misfire codes may be detected with the Tech 2 scan tool.
A deposit build-up on the CSFI poppet valve ball and/or seat may cause the poppet ball to stick open or closed. In either case, the specific cylinder will be mis-fueled, resulting in a cylinder mis-fire condition.
A new injector unsticking and cleaning process has proven to be effective in restoring poppet valves to an "as new" condition. CSFI injector replacement should NOT be considered as a correction for this customer concern.
Check the vehicle history to determine if the vehicle is returning for a second fuel system repair for this condition. If the fuel system has been repaired for this condition previously, then inform the customer that an alternate fix is available. A new MFI fuel system has been developed that will back service the CSFI fuel system. The MFI fuel system eliminates the CSFI poppet valve ball and seat. The CSFI fuel system will need to be replaced as a unit. Refer to Central SFI to MFI Conversion instructions in this bulletin.
Notice : Individual CSFI injectors can not be replaced with MFI injectors. The entire CSFI fuel meter body will need to be replaced. The bracket used to retain the injectors in the fuel meter body is different between the CSFI and MFI unit. The unit may not seal if you mix injectors. Severe engine damage could result.
Cleaning the CSFI injectors is the preferred repair. The CSFI unit should not be replaced until cleaning has been attempted. If the vehicle should return for the same repair, then the CSFI unit can be replaced with an MFI unit. If the vehicle is out of warranty, the customer should be given the option of which fix to pursue.
Important : "GM of Canada" dealers require District Service Manager approval prior to replacing the CSFI unit with a MFI unit under warranty.
The first step of this process is to use the J 41413 Evap Pressure/Purge Station, in conjunction with the J 44466-10 pressure regulator/hose assembly, to provide the required high pressure (150 psi) source to perform the unsticking procedure. The J 39021 fuel injector tester and accessories provide the means to "energize" the injector. Some later model-year vehicles may utilize the Tech 2(R) to "energize" the injectors.
The second step of this process is to run the engine on a solution of 10% Top Engine Cleaner and 90% gasoline. This will effectively clean any deposits from the ball and seats of the poppets. It is very important that the engine fuel system is separated from the vehicle fuel system. Top Engine Cleaner may have detrimental effects on the fuel pump.
#572 of 2018 Re: sputters idles up and down sputters when going up a hill [canufixit]
Mar 23, 2005 (8:01 am)
Canufixit, I'm new to the site and have a question re. 95 S10 2.2 2x2 I bought recently as a project. Plan to replace engine w/ mouse motor out of 2001 camero which received a 383 stroker but for now just playing with the 2.2. Pulled and replaced cyl head, cleaned injectors, new tps, new iac, new plugs,wires, fuel pressure regulator, etc. Now engine idles fast and has no power. Strong fuel smell at tail pipe. I'm thinking stuck exhaust valve on new head. Any ideas? Thanks. Bill Mc
#573 of 2018 Re: 99 4x4 4.3L 5spd- Losing power during acceleration... [londog77]
Mar 23, 2005 (8:07 am)
Ok, One more suggestion ...
I have "heard" of the intake manifold to head gasket leaking in the front or rear ends of the manifold. This will allow coolant into front or rear cylinders ... If it is just leaking a little - you get a rough engine - if it's leaking a lot - it can fill up the pistons affected and cause a hydrostatic lock - and the engine will not turn .... Try a compression test on the cylinders ..... and look at the plugs when you pull them to see if they look wet (and smell them for the antifreeze ...).
All I can think of right now ....
#574 of 2018 Re: Transmission Whining [draggn66]
Mar 23, 2005 (8:12 am)
In My case (on my truck) - the sweet spot is at 40 MPH. Just under /around/ just over 40 MPH on a light load on the drive train - the rear end whines. Take your foot off the gas - and it goes away. give it a little more gas and it gets louder - give it a lot of gas and it almost goes away. This is listed as "Normal" at 40 MPH in the shop manual for my Sonoma. It's not bad - so I just ignore it - but the root cause is incorrect pinion gear loading (shims) when the rear end finally broke in and the mechanicals finally seated ...
Mar 23, 2005 (9:05 am)
I recently purchased an 02 S-10 from a local Dealer (not chevy) and have discovered the carpet on the driver's side is soaked during rains. I can't find any source for the leak. Suspect cowling under wipers but don't know. Any thoughts suggestions? I can't find any information on the drainage sytem for the cowling fresh air intakes.
#576 of 2018 Re: wet carpet [02_wet_carpet]
Mar 23, 2005 (12:30 pm)
See an Earlier Post I made on this - not sure if this is your problem though - Mine was the seam between the roof and the corner post not being sealed in the inside ...
#577 of 2018 Re: sputters idles up and down sputters when going up a hill [87vette]
Mar 23, 2005 (1:03 pm)
If memory serves me - a vacuum gauge will quickly show a stuck valve. Instead of a steady state at Idle the needle will "dip" drastically on every revolution of the engine ...
I'd do a Cylinder pressure test (wet and dry) on each cylinder as well. With the pressure test and vacuum checks you'll have a better idea of the mechanicals and also a record for future reference ...
A stong fuel smell at the exhaust may be Ok when the engine is still cold as more gas is poured into the engine until it get up to Temp. But as you said a "Strong" smell may not be right ...
#578 of 2018 Re: Chevy S-10 Fuel Pump [dblaine]
Mar 23, 2005 (1:09 pm)
Can you jumper the fuel pump ?? - if you can get the pump running and the engines runs OK for a good while - at least you'd know that the pump is OK and its' the supply voltage/circuit to the pump that's the problem. This may help you in removing some of the variables in the equation. If it does not run - re-check the pump - it it runs - troubleshoot the wiring....
#579 of 2018 Re: Cajun, [leadfoot4]
Mar 23, 2005 (1:16 pm)
I had an uner chassis rear rattle on intial engine start up - turned out to be a loose baffle plate inside the muffler.
I'd get under the truck and really shake the exhaust - check both the muffler and the Converter (expecially the heat shield!!!)
#580 of 2018 Re: Coolant change on S-10 [jae5]
Mar 28, 2005 (6:19 am)
I was having the same problem with my 2002 S-10. I had a coolant leak at the thermostat housing and needed to drain the radiator but could not find an easy way to "turn" the plastic petcock. After maneuvering an inspection mirror into position, I could see an allen head fitting in the center of the petcock. I inserted a 3/8" allen wrench into the center of the petcock, and turned it counterclockwise approximately one quarter of a turn. It "popped" out slightly allowing coolant to flow from the radiator.