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2002 egr valve not there

9K views 27 replies 6 participants last post by  scott936 
#1 ·
I tried posing this in Engines but the is no new topic button in that section??? According to the manuals I have, the INTERNET research Ive done a 2002 astro should have an egr valve next to the T stat housing... Well mine doesn't, I checked the vin its a 2002, is it possible that its a late 2002 and has the engine of 2003 that doesn't have an egr???

If there is no egr then what would cause the rough idle?
Ive replace
Cap, rotor, plugs, wires, tps, iac, fuel filter, coil, check vac houses,
 
#2 ·
A partially clogged fuel injector , low fuel pressure , failing fuel regulator , improper gapped plugs , intake manifold vacuum leak are a few possibilities , sometimes the easiest way to find the problem is to have a OBD2 diagnostic live scan that shows the live current activity of all the components in the circuit that indicates what is actually happening .
 
#3 ·
Phantom said:
A partially clogged fuel injector , low fuel pressure , failing fuel regulator , improper gapped plugs , intake manifold vacuum leak are a few possibilities , sometimes the easiest way to find the problem is to have a OBD2 diagnostic live scan that shows the live current activity of all the components in the circuit that indicates what is actually happening .
ok thanks for the input. Any ideas about the EGR deal? Now I'm very curious if this is possible
 
#4 ·
Phantom said:
A partially clogged fuel injector , low fuel pressure , failing fuel regulator , improper gapped plugs , intake manifold vacuum leak are a few possibilities , sometimes the easiest way to find the problem is to have a OBD2 diagnostic live scan that shows the live current activity of all the components in the circuit that indicates what is actually happening .
I have found one of my tool salesmen has a live scanner I can use but I need to find the specs on a 2002 so I can see what is not with in spec, any ideas where I can find those?
 
#5 ·
scott936 said:
I have found one of my tool salesmen has a live scanner I can use but I need to find the specs on a 2002 so I can see what is not with in spec, any ideas where I can find those?
Factory service manual should have them , I use a software program , but it is not currently installed as i am doing service work on that computer , maybe someone here has a manual that can look up the specs , about the egr , on the production line it is easily possible that you got a 2003 engine if it was built in the later part of model year close to the 03 release , or possible that 03 top engine parts were installed on an 02 engine , in a production environment they use whatever is close and handy to keep the production line moving when they run out of parts and they have to wait for more to be transported to the assembly line as down time is very costly to the factory .
 
#6 ·
Kind of a new development has come up, my service engine soon light has come on for the 3rd time the code is misfire #6 cylinder at that point the van idle goes very erratic almost to the point of stalling. Now it has new plugs, wires, cap , rotor & coil all GM stuff.
My question is can the distributor module have an issue with just one cylinder? The Van has 145,000 on it the module is original, the plugs and wires have about 6000 on them at this point. Wednesday I'm planning to pull the plug and wire, I will ohm out the wire just to make sure.

Any input would be helpful
 
#8 ·
When you say dist module , you mean the camshaft sensor? does your engine have any of the other components of a egr system?

it could be that the plug wire is not securely connected just loose , make sure you have the firing order correct as well

other possible causes

broken or burnt exaust valve spring
Poor compression
Defective computer
Faulty spark plug or wire
Faulty oxygen sensor(s)
Faulty fuel injector
Vacuum leak(s)
Low or weak fuel pressure

Defective Mass Air Flow Sensor
Defective Crankshaft and/or Camshaft Sensor
Defective Throttle Position Sensor

Here is some info you may find useful

http://www.engine-light-help.com/check- ... sting.html
 
#9 ·
Hi scott936

Great advice given so far.

Just to make my input here, is the "X" engines don't have EGR valves. I don't know what engine you have, but that year is close to when the EGRs were eliminated all together.

You can find your engine type by lookig at he 8th digit on the VIN Plate.

If this miss occurred after the tune-up, then I would suspect a loose or defective plug wire or a broken/cracked plug. Number 6 is the toughest plug to do out of all the others, and I have cracked my #6 (very easily I might add) on one occasion.

That's when I went to the "Swivel" socket. This evens out the torque when tightening the plug which is in a very awkward spot to reach.

If the SES light triggered, what was the code given, thanks.:)
 
#11 ·
speedy57 said:
Do the (X) engines not have a EGR system at all :confused:
According to the book 2003 and newer no EGR.... That why I asked about late 2002 production having a 2003 engine because I have no EGR????
 
#13 ·
Phantom said:
When you say dist module , you mean the camshaft sensor? does your engine have any of the other components of a egr system?

it could be that the plug wire is not securely connected just loose , make sure you have the firing order correct as well

other possible causes

broken or burnt exaust valve spring
Poor compression
Defective computer
Faulty spark plug or wire
Faulty oxygen sensor(s)
Faulty fuel injector
Vacuum leak(s)
Low or weak fuel pressure

Defective Mass Air Flow Sensor
Defective Crankshaft and/or Camshaft Sensor
Defective Throttle Position Sensor

Here is some info you may find useful

http://www.engine-light-help.com/check- ... sting.html
Just my thought process so please bare with me.
Valve spring issue - wouldn't I see that through the RPM range and be a constant issue?
Poor Compression - Same thought a Valve spring
Defective Computer - I can see that being a problem
Fault plug and or wire - I can see that being a problem
Faulty O2 - Wouldn't I get an O2 code
Fuel injector - Wouldn't it be constant and wouldn't it effect the rest of the bank
Vacuum leak - I can see that being a problem
Fuel pressure - wouldn't I see some other issues at speed with a higher demand???

This problem is working my last nerve, the van runs good at speed and at time idles ok then something happens and it idles like a diesel and throws a code it may last an hour or a few days depending on her mood..... Van pause maybe????

Today I'm getting a scanner with live feed, should be able to give some numbers later today and just maybe come up with a solution
 
#14 ·
They do have an emissions system, but it's designed differently than the typical egr setup. It was computer controlled with the Xs (to my understanding).:)
 
#15 ·
Matrixx said:
They do have an emissions system, but it's designed differently than the typical egr setup. It was computer controlled with the Xs (to my understanding).:)
You are correct... I talked with a tech today in detail about my problem and learned some interesting things. It seem that the "spider" is a very common failed part on the astro and after hearing the vans symptoms he believes #6 on the spider is the problem.

I will do all the testing anyway to make sure before I get to excited about this repair... Ive done some of the live feed testing but the scanner I'm using is limited, the high dollar scanner wouldn't work today dure to a card issue...My luck... I will post what info I get later today

Thanks for your input.
 
#16 ·
Ok this is the live data I have so far -

RPM at idle in park with AC on 602
RPM at Idle in drive with AC on 553
RPM at idle in drive AC off 600 AC Starts drops to 406 then back to 600

STFT B1 0 to .8
LTFT B1 .8
STFT B2 0 to 1.6
LTFT B2 -1.6

Spark Adv at idle with AC on 17.5

I will get compression readings and Vac info on Wednesday, that my next slow day. OK Astro Van gurus tell me what all this means...
 
#17 ·
LTFT Long Term Fuel Trim
STFT Short Term Fuel Trim, is a program in the vehicle's computer designed to add or subtract fuel from the vehicle to compensate for operating conditions that vary from the ideal A/F ratio. The vehicle uses this program to make minor fuel adjustments (fine tune) on a short-term basis
STFT B1 --> B1 = Bank1
LTFT B1
STFT B2 --> B2 = Bank2
LTFT B2

The numbers reflect how much adjusting the PCM had to do to get the Air fuel ratio back to its intended range , closer to zero the better , but there are factors that can cause things to be way off since the PCM can only adjust to limited parameters , when components go bad they can be outside the limits of adjustment of the PCM .

Your numbers look like they are within reasonable spec , but without the exact spec they are supposed to be it is hard to say .
You would need to run all the diagnostics to find where the miss is , finding out if the coil is putting out the right voltage , if every cylinder is firing right on time getting measurements of every cylinder and comparing , kinda like comparing cylinder compression , typically the one that reads out of range from the others is the problem cylinder, but sometimes several cylinders are missing the right compression mark , finding if the crank sensor is firing consistently with in spec there is a lot of detailed stuff a scanner can do , and depending on what the scanner is capable of. Which is why you need a table chart that shows what the proper measurements should be and then compare your readings to what they are supposed to be

I prefer the laptop type because they can do more than the hand held type . GM has actually abandoned the hand held Tech2 type for a couple years now , its all computer based now , the only reason they may still have or use the Tech2 style is for the older vehicles
 
#18 ·
Phantom said:
LTFT Long Term Fuel Trim
STFT Short Term Fuel Trim, is a program in the vehicle's computer designed to add or subtract fuel from the vehicle to compensate for operating conditions that vary from the ideal A/F ratio. The vehicle uses this program to make minor fuel adjustments (fine tune) on a short-term basis
STFT B1 --> B1 = Bank1
LTFT B1
STFT B2 --> B2 = Bank2
LTFT B2

The numbers reflect how much adjusting the PCM had to do to get the Air fuel ratio back to its intended range , closer to zero the better , but there are factors that can cause things to be way off since the PCM can only adjust to limited parameters , when components go bad they can be outside the limits of adjustment of the PCM .

Your numbers look like they are within reasonable spec , but without the exact spec they are supposed to be it is hard to say .
You would need to run all the diagnostics to find where the miss is , finding out if the coil is putting out the right voltage , if every cylinder is firing right on time getting measurements of every cylinder and comparing , kinda like comparing cylinder compression , typically the one that reads out of range from the others is the problem cylinder, but sometimes several cylinders are missing the right compression mark , finding if the crank sensor is firing consistently with in spec there is a lot of detailed stuff a scanner can do , and depending on what the scanner is capable of. Which is why you need a table chart that shows what the proper measurements should be and then compare your readings to what they are supposed to be

I prefer the laptop type because they can do more than the hand held type . GM has actually abandoned the hand held Tech2 type for a couple years now , its all computer based now , the only reason they may still have or use the Tech2 style is for the older vehicles
Wow, thanks for the information.. Is there a software I can buy for my laptop that you would recommend to give me the needed data?
 
#19 ·
With OBD2 you need a hardware interface to plug into the OBD2 diag port , with OBD1 just a cable with the proper end on it would work , but with OBD2 the interface is required to use the proper protocol to make the communication between the car and the laptop.

Most companies prefer to make their stuff proprietary just so it doesn't work with other companies stuff ,

EFI Live
HP Tuner
Tuner Cat
Digimoto
Snap-On Shop Stream

Just a few choices

There are many software you can use , here is an interface that I have found to be good quality , there are some products similar to it for about 40 bucks cheaper but the quality of the circuit and case are not as durable and are inferior to this product and they have free tech support if you need help . with their product many different software can be used , they have a few more choices on their website.
http://obd2allinone.com/sc/details.asp?item=obd2usb
http://obd2allinone.com/

http://obd2allinone.com/sc/details.asp?item=12combo

The Tuner programs can actually flash the ECM/PCM to new custom settings , but before you attempt that make sure you learn how to use the program and what it does , just so you don't change something that you don't need or want changed , the process is like flashing the BIOS on a desktop computer , make sure there is no power interruption when flashing , that is critical
 
#20 ·
Phantom said:
With OBD2 you need a hardware interface to plug into the OBD2 diag port , with OBD1 just a cable with the proper end on it would work , but with OBD2 the interface is required to use the proper protocol to make the communication between the car and the laptop.

Most companies prefer to make their stuff proprietary just so it doesn't work with other companies stuff ,

EFI Live
HP Tuner
Tuner Cat
Digimoto
Snap-On Shop Stream

Just a few choices

There are many software you can use , here is an interface that I have found to be good quality , there are some products similar to it for about 40 bucks cheaper but the quality of the circuit and case are not as durable and are inferior to this product and they have free tech support if you need help . with their product many different software can be used , they have a few more choices on their website.
http://obd2allinone.com/sc/details.asp?item=obd2usb
http://obd2allinone.com/

http://obd2allinone.com/sc/details.asp?item=12combo

The Tuner programs can actually flash the ECM/PCM to new custom settings , but before you attempt that make sure you learn how to use the program and what it does , just so you don't change something that you don't need or want changed , the process is like flashing the BIOS on a desktop computer , make sure there is no power interruption when flashing , that is critical
thanks for all information and help. I will get the compression and vac info on Wednesday.
 
#21 ·
New test done today fuel pressure:
At idle in park 49-50 psi
In Park at 1800 rpm 46 psi
Key on engine off 53 Psi

According to my book it seems low, what are your opinions
 
#22 ·
scott936 said:
New test done today fuel pressure:
At idle in park 49-50 psi
In Park at 1800 rpm 46 psi
Key on engine off 53 Psi

According to my book it seems low, what are your opinions
Yes it very low , it should be over 60 psi and not lower than 58 59 area, it could well be your problem , engine not getting enough fuel to run smoothly, if it is not it will be soon. Time to replace , use only a Delphi or Ac Delco brand fuel pump , or you will change it again in a year, change the in tank fuel sock with it and be careful when handling the unit when you pull it out and put it in , a fuel filter should be replaced with it .
 
#23 ·
Phantom said:
scott936 said:
New test done today fuel pressure:
At idle in park 49-50 psi
In Park at 1800 rpm 46 psi
Key on engine off 53 Psi

According to my book it seems low, what are your opinions
Yes it very low , it should be over 60 psi and not lower than 58 59 area, it could well be your problem , engine not getting enough fuel to run smoothly, if it is not it will be soon. Time to replace , use only a Delphi or Ac Delco brand fuel pump , or you will change it again in a year, change the in tank fuel sock with it and be careful when handling the unit when you pull it out and put it in , a fuel filter should be replaced with it .
Ok I will order it now with the sock, thanks for your help. I will get that replaced and then we will see how it runs and proceed form there

Thanks
 
#25 ·
Well its been a couple of days since the fuel pump switch and about 500 miles, what i have learned is this.

Fuel swap was a breeze, no problems
At first there was little to no improvement but as i drove it it did seem to improve the idle.
I did put my Vac gage on it and it showed that the time is retarded some what.

Since I'm taking our van on a 1000 (round trip) business trip I sending to a buddy (Mr goodwrench) of mine to figure out what the problem is.
 
#26 ·
If you end up needing a spider assembly,and plan on keeping the van, I'd go with the later model vin "X" spider. It's an upgrade, and you need the spider and the retaining bracket, and it eliminates those POS poppets. Basically, where the injectors fit in the housing on the original unit, it's just a plenum, and it has real injectors on the end of the fuel distribution lines, in place of the poppet assemblies. :2:
 
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