Scyimon
Forum Newbie
Posts: 3
Reg: 07-13-12
|
07-13-12 06:55 PM - Post#2247941
Hey all. I have a 1995 G30 van that has been used as a utility vehicle for the better part of its life. I just recently did a partial tune-up do to this issue and was hoping you all could potentially point me to one of a group of parts that I think might be causing the issue. Also, exhaust is shot, I mean completely rusted from the muffler back. Have new one on parts list but drove 1600 miles with it as is and no issue.
Issue:
After 30 to 45 minutes of driving, the engine will stall out no matter the throttle position (idle to floored). I then have to wait a minimal time of 30 minutes up to 2 hours before the vehicle will start regularly otherwise it will start and stutter then die. Sometimes it will start back up while moving if I pump the gas but will soon stall again (1 to 5 minutes)
Item noticed during:
Drop in oil pressure when letting off throttle
Slightly elevated engine temp from normal
Computer is hot to the touch (located under drivers seat in black carrier)
Possible parts causing the problem (suggested from parts stores and shadetree mechanics)
EGR
Computer (due to temp)
Ignition Coil
Ignition control module/system
Tune up consisted of new spark plugs (old ones were rusted and corroded, air filter, oil change, code check, Radiator flush and fill, transmission flush and fill. Also, cleaned the throttle body and seafoam added to both oil and gas.
I have an 1100 mile trip coming up to see my kids for the first time in 8 weeks and really would like to get this solved as soon as possible. Thanks in advance.
Edited by Scyimon on 07-13-12 06:58 PM. Reason for edit: No reason given.
|
|
 62chevy427
"7th Year" Silver Supporting Member
Posts: 1499
Loc: laurens sc
Reg: 04-13-06
|
07-13-12 08:02 PM - Post#2247973
In response to Scyimon
i would suggest something electronic getting hot and shutting down. if your computer gets real hot,try to cool it off quickly to see if it will start again. i suggest removing it and putting it in the refrigerator. could be something else,but i would start there. also check all grounds and power feeds. clean and retighten.
56 bel air ((since 2002)
62 impala ss (since 1965)
65 el camino (since 1969)
66 nova (since 1987)
67 malibu convertible (since 1981)
72 el camino ss454 (since 1985)
83 gmc 4wd (since 1991)
95 impala (new)
11 malibu (new) |
|
drifterdude
Frequent Contributor
Posts: 1282
Reg: 09-04-08
|
07-13-12 09:06 PM - Post#2247999
In response to 62chevy427
I would not suggest the fridge. Sudden temp change could cause condensation and fry it.
I would suggest if possible if its hot is to get a fan that plugs into the lighter socket just a cheapo one and extend the wires and aim it at it to keep it cooler and see if it helps.
It should get warm but not enough to burn you.
92 K1500:350 bored 30 over,built 700r4,Comp extreme energy cam,double roller timing set,shaved heads,Rancho RS9000XL series shocks with wireless my ride system,35 inch Mickey Thompson Baja Claws,Relocated 4x4 switch to rocker on Dash.
Other mods.. |
|
355Cheyenne
Senior Member
Posts: 3743
Loc: Northern MN
Reg: 10-27-04
|
07-13-12 10:03 PM - Post#2248004
In response to Scyimon
change your CTS (coolant temp sensor), refer to the FAQ for specific instructions. Many times I have seen vehicles stall as they get up to operating temperatures.
The ECU getting hot doesn't mean much to me as what do you have to compare it too? may be normal. These older electronics use the aluminum case as a heat sink for the transistors so the case gets warm to hot.
The other suggestions from the coil the ignition module are also possibilities and can be tested. bring the module in and most parts stores can test them. Sometimes when they get hot they fail, that is also true with coils and that can be tested with an ohm meter.
Final possibility which is worst case, you said oil pressure drops, if your motor is worn bad enough that is has low enough oil pressure the fuel pump will cut off. So as the temps increase the oil thins and pressure drops and in a worn motor this could drop to zero. TBI will cut fuel if pressure drops that low. This could be tested but increasing the RPM to increase oil pressure and if that keeps the engine running then it may be time for a motor rebuild/replace.
| 98 Silverado k1500 4x4 350 |
|
Scyimon
Forum Newbie
Posts: 3
Reg: 07-13-12
|
07-13-12 11:12 PM - Post#2248015
In response to 355Cheyenne
The engine is a 95 so hopefully don't need a rebuild already. I will try a fan as I already have a few of the 12v clamp on type in my RV that I'm not using right at the moment. Taking the coil and ignition module in to be tested tomorrow. Is there a way to test the ECU to see if it is going aside from taking it to a shop as the shops here are backed up at least 3 weeks if not more for some. I only mentioned the oil pressure as was noticed after this issue started but even trying to keep it reved up it still stalls out on me.
|
 someotherguy
Moderator
Posts: 23385
Age: 43
Loc: Texas
Reg: 08-01-03
|
07-14-12 05:50 AM - Post#2248048
In response to Scyimon
Welcome to Chevytalk,
I'd put the PCM (computer) at the bottom of the suspect list as they very rarely fail.
Ignition module inside the distributor, move it to the top of the suspect list. If you replace it, do not fail to clean off the old heat sink compound from the distributor, and apply a thin but even layer of new compound to the new module. You want enough to completely coat the metal portion of it where it contacts the distributor base, but not a sloppy amount; too much of the stuff becomes counterproductive. Be sure you're using actual heat sink compound (also sometimes referred to as thermal grease) - very commonly some parts house guys and other people will call it dielectric grease and this is incorrect; they are two totally separate products and dielectric grease will not do the job.
Before replacing anything though, you're in a good position for troubleshooting in that it takes time before you can start it again. Consistency is good. Immediately when it dies you should be ready with a fuel pressure gauge and a spark checker, to see what's happening. Info on both tools and how to use them in the FAQ post at the top of this forum listing, under the heading "Won't start"
Richard
|
Allan In NE
Contributor
Posts: 903
Reg: 12-27-11
|
07-14-12 05:59 AM - Post#2248054
In response to Scyimon
30-40 minutes?
Coil, possible fuel pump.
Allan
| Lifelong GM automatic transmission specialist |
|
elcamino
Valued Contributor
Posts: 4812
Loc: Lake Superior-Michigan US...
Reg: 03-30-00
|
07-14-12 11:03 AM - Post#2248136
In response to Scyimon
In the early to mid-90's some computers had problems. The way to test it is when the vehicle is running, take a plastic handle screw driver and tap lightly on the computer with the handle. If it has a bad circuit it will stall right out. A GM tech told me about this years ago. Cannot recall if the computer problems were also in trucks but I know for a fact there were is cars as I know someone with that problem in a 93 Chevy car.
Mike
2009 Cadillac CTS4 AWD Performance Sedan
2012 GMC Sierra AWD Denali 6.2L |
|
elcamino
Valued Contributor
Posts: 4812
Loc: Lake Superior-Michigan US...
Reg: 03-30-00
|
07-14-12 11:43 AM - Post#2248149
In response to elcamino
Also, if you have any made in China ignition parts, get rid of them and put in AC Delco. Some of far east electonic parts have very cheap circuit boards or have smaller parts that make them junk. And be careful, even the well known brands have made in china parts in thier boxes. Ignition modules are high on the list of shoddy far east parts, they are so cheap that when they get hot they fail.
Mike
2009 Cadillac CTS4 AWD Performance Sedan
2012 GMC Sierra AWD Denali 6.2L |
|
Scyimon
Forum Newbie
Posts: 3
Reg: 07-13-12
|
07-14-12 05:10 PM - Post#2248221
In response to Allan In NE
As I was pulling the distributor cap and associated parts to get the module tested, noticed a fair amount of rust and corrosion on the plug wire contacts and the rotor and cap contacted were scorched like crazy. I have now replace all three along with the coil and no issue during or after 100 mile test drive.
Only thing now is the oil pressure keeps dropping at idle down to the lowest hash mark on the gauge (I assume it 20psi as the gauge only goes to 80 and has 3 hash marks between that and 0) Normally runs between middle and 3rd hash (50)
|
someotherguy
Moderator
Posts: 23385
Age: 43
Loc: Texas
Reg: 08-01-03
|
07-14-12 06:21 PM - Post#2248234
In response to Scyimon
"Scorched" appearance of the cap and rotor is usually the spark firing through the plastic erratically as the parts have gone bad and are no longer insulating properly. Also typically referred to as "carbon tracking." It sounds like maybe it's been a long time since a proper tune-up.
The oil pressure sending unit isn't famously reliable; over time they go bad and read lower and lower. To be sure you should confirm readings using a mechanical oil pressure gauge.
Bare minimum oil pressure according to GM spec on the TBI 5.7 is lower than you might think. The figures the manual gives are minimum of 6 psi at 1000 RPM, 18 @ 2000, 24 @ 4000.
I would personally be very nervous if I was getting close to that minimum spec, but on these TBI generation engines, around 15~20 psi warm idle is common and nothing to worry about.
Richard
|
|
Gain extra benefits by becoming a Supporting Member 
drtyler (4)
