More problems Code 32

[Dog House]

Hello again, I hooked a Snap-On MT2500 scanner and one of the things it came up with was that it had a VAT Problem? what is a VAT problem? :confused

 

[John Robinson]

If you could see how the hoses are on this car it does not make sense. It appears someone had possible removed the engine or something and forgot how to hook everything back up. The diagram makes sense the car does not. I just found two more hoses that are broken off and have no idea where they go. They split off of one hose coming from the round canister in the front left fender. This car is a cluster! Guess I better just start from scratch using the diagram you posted.

It appears from this that you bought the car from someone who sc---- it up and could not fix it. Also from what you say I would guess this individual did not have any mechanical ability (sledge hammer mechanic). From following this thread I would suggest that you remove the valve covers and carefully reset the valve tappet clearences. It sounds like the valves are too tight and when you put the exhaust system back on you created back preassure which makes it run even worse. In fact you might be led to believe that the resonator or some other part of the exhaust is clogged up.

 

[Dog House]

Probably no need to mess with the valves, after ruining the scan I noticed the TPS voltage was .66 so I re-checked the low idle speed at normal running temperature and re-set the TPS volts to .54 she’s running a lot better. Boy are these engines temperamental if one setting is out of wack they run like crap. I’m going to let it cool down which wont take too long as it 38 degrees right now, then going to start it cold and see if it idles without having to give it gas which it would not do before.
Bummer, now I’m looking foreword to spring. Going to be a long winter, LOL

 

[Dog House]

Here is the results of the scan with and with out the engine running. Do these numbers look normal? I’m unable to find any reference in my FSM. Thanks!

Initial Scan Engine Off codes 42 & 44 where present. Deleted codes for running scan.


Scan Engine Off
Scan Engine Running



RPM
0
500
02 (mv)
398
398
Intergrater
128
128
Open/Closed Loop
Open
Open
Exhaust Oxigen
Lean
Lean
TPS
0.58
0.68
Block Learn
128
150
IAC Position
160
160
FT Cell
0
0
02 Reading
No
No
02 Crosscounts
0
0
Base PW (ms)
0
4.6
Decel Learn
No
No
Desired Idle
3188
1000
A/F Learned
No
No
Coolant Degree F
94
91
MAT Degree F
82
73
MAF (9m/Sec)
23
14
Air Flow (9m/Sec)
64
13
Load/LV8
0
96
Spark Adv
0
38
Knock
No
Yes
Knock Retard
0
0
Prom ID
1021
1021
Battery
11.8
13.6
Fuel Range
0
13.8
High Bat
No
No
MAF Burn Off
Off
Off
EGR Duty %
0
0
EGR DIAG SW
On
On
CCP Duty Cycle
o
o
Decel Enlean
No
No
Air Divert Sol
DIV
Norm
Air Switch Sol
CONV
Port
Coolant Degree F
92
91
Start CLNT Degree F
92
91
Fan Reguest
No
No
Fan Duty
0
0
VATS Problem
Yes
Yes
Battery (Y)
11.8
13.6
Hi PS Pressure
No
No
Vech Speed
0
0
P/N Switch
P-N
P-N
TCC Command
P1
P1
TCC Apply CKT
No
No
4th Gear
P1
P1
OD Switch
On
On
A/C Request
No
No
A/C Clutch
Off
Off

 

[Dog House]

I forgot to mention when setting the base timing in order to get it to 6 degrees above TDC the square part on the side of the distributor cap with wires going into it was darn near but up against the plenum. Looking at other corvettes they have plenty of room for adjustment before getting close to the plenum.

Would this be a sign of having a problem with the timing chain jumping a tooth on the gears and or maybe someone was in there changing the chain and or gears and didn’t have them lined up correctly thus causing a lot of my poor running condition?

 

[John Robinson]

I forgot to mention when setting the base timing in order to get it to 6 degrees above TDC the square part on the side of the distributor cap with wires going into it was darn near but up against the plenum. Looking at other corvettes they have plenty of room for adjustment before getting close to the plenum.

Would this be a sign of having a problem with the timing chain jumping a tooth on the gears and or maybe someone was in there changing the chain and or gears and didn’t have them lined up correctly thus causing a lot of my poor running condition?

That is a good indicator that things are not right. The first easy thing to do is remove the rocker covers and go through the valve adjustments. Easy as you do not have to disassemble the front of the engine and you might just get lucky. Another thing to do is check to see that the distributor is properly aligned and positioned in block. As you said earlier this is a basket case and you have to assume that nothing is right until you verify that it is. From what you said about the vacuum hoses etc not being right you have to know that the previous owner was not a meticulous careful workman who paid attention to the details. if your lucky they did not get inside of the engine and all your problems are just a matter of redoing ever thing one at a time until you find the answer. Shoot it only took me 8 months to fix my cruise control but I did it for $5.00 not the hundreds I was being told it needed which basically was keep replacing parts until something works

 

[Dog House]

Thanks John, I did check to see that the distributor is in correctly by bringing #1 cylinder up and the rotor was pointing to the #1 spark plug wire connection on the cap. As far as being lucky under the rocker covers, if the valves are not adjusted correctly would that cause the alignment of the distributor being so far off? Or what should I be looking for?

 

[John Robinson]

Thanks John, I did check to see that the distributor is in correctly by bringing #1 cylinder up and the rotor was pointing to the #1 spark plug wire connection on the cap. As far as being lucky under the rocker covers, if the valves are not adjusted correctly would that cause the alignment of the distributor being so far off? Or what should I be looking for?

In my experience if the valves are overtightened the engine runs rough and acts like it is tight. The first time I really saw this I was in a garage that was working on a 396 Cheville that they had rebuilt and added performance goodies to. I had stopped to buy gas and my ears took me inside to see what was going on. They had been trying for a week to get it to run and idle. It was sitting there shaking, missing and back firing on idle. They had the rocker covers off so I suggested that they start to loosen the valves up to see if they could smooth it out. After they had done one side it started to run better and by the time they had done the other side it was idling and would take the throttle without backfiring. They then went though the drill to properly adjust the valves and it sounded like an engine that was ready to beat the world. As for the distributor pointing to the number one wire at TDC I wonder if you were 180 out on the compression stroke. Next even if you were not 180 out you still do not have any idea if the valve was hanging open when the rotor was firing across to the distributor. The next thing I would look at is to see if the cam lobe is pushing the pushrod up into the rocker arm when the rotor points to the number one cylinder in the distributor. As we all know but sometimes forget all we need to make an engine run is spark fuel and air in the right combination at the right time. I pass this on only as a guide for you and not to tell you what to do I am old and have made my own mistakes over the years and so I am only trying to pass a little of what I have tried and hope it will help solve your problems

 

[Dog House]

Thanks again John, I’ll look into all of this in the spring. I’m in Minnesota without a garage so the car is all covered and put to bed for the winter already covered with snow. :ugh

Happy Holidays and God bless everyone on this forum.
There are a lot of experienced people here with an overwhelming amount of good information to consume, between all of you and my FSM I should be able to get this car running as it should.

 

[John Robinson]

Thanks again John, I’ll look into all of this in the spring. I’m in Minnesota without a garage so the car is all covered and put to bed for the winter already covered with snow. :ugh

Happy Holidays and God bless everyone on this forum.
There are a lot of experienced people here with an overwhelming amount of good information to consume, between all of you and my FSM I should be able to get this car running as it should.

I have family that lived in the Staples, Detroit Lakes, Wadena area in fact in 1988 my wife and I took a train from Indianapolis to Staples and picked up a new car at the Chevy dealer there and went on a two week vacation. The wifes Sister and two children are buried in Wadena.

 

[Dog House]

Well its 57 degrees in Minneapolis today so I’m back working on my basket case vette. I was able to fix the distributor position problem today and reset the timing, idle, and IAC then proceeded to look around the engine compartment and what do I see?

I noticed the MAF was mounted upside down with the wire harness on top so I took off the air filter duct and loosened the clamp to the duct going to the TB and turned it 180 and what do I fine??? There is a hole in the MAF caused from rubbing on the disk that is mounted to the water pump pulley. Correct to assume I’ll need a new MAF? I would think this may have a lot to do with the way this car runs?

Never ending problems! Every place I this car I find something else wrong.

 

[vetteboy86]

So are you getting and engine code telling you the maf is faulty? I would inspect it closely, along with the wires. If there isn't enough slack, the wires were under tension. Also check the metal wire inside the maf. All that vibration could have damaged it.

I'm not sure I would patch it. I suppose you could though.

 

[Dog House]

No codes, haven't looked inside of it other then last fall to notice the screen has been cut out.

 

[Dog House]

I’m back working on the car again and just got through changing the o2 sensor and fuel filter and it still runs like you crap. While I was just running it from time to time it would purr like a kitten and then it would bog and run like crap again. I took it up the road and at first it was running good and very responsive lots of get up and go then right back to running like crap then it would start running good again then like crap. I'm not sure if it a lack of fuel or too much when it is running bad it just bogs spits and sputters and even heard a couple back fires. Anyone have any ideas what I’m up against?

 

[John Robinson]

Two More things to look at

The EVAP system if it is not right will cause a rough idle along with other things. From what you have already said I would make absolutely sure the evap was correctly hooked up and functioning correctly.
Next take a hard look at the EGR and it's vacuum solenoid. The next time you get it running good and it goes to running bad take and tap the egr valve to see if that changes anything. You can also use a long screwdriver to push in on the diaphragm with the engine warm and it should die if not really look at the egr then.

Like you said you have a basket case which means the previous owner was clueless about how to fix this car. With all the things he did wrong that you have already found you can expect to find more. Do what I do get your curved pipe and your Sherlock Holmes hat and have at it.

 

[boomdriver]

well, the description sounds like maybe a MAF fault. Did you replace or repair the old one? And are there any new codes? I'd check the codes after the poor running and clear them, then run it and ck again.
Usually if the MAF is bad it will burp and puke on itself when throttle is applied until the ECM jumps to LHM and then it smooths out, but it should stay there (LHM) until the key is turned off then it may want to go thru the process again until the fault is corrected.
I have seen the MAF rolled over before, usually its because the plug is difficult to get in or there is wire hanging down in things. I have run mine like that before. It does'nt harm anything.

Something else regarding the inconsistant performance, is maybe a loose contact on the distributer. If the batt wire is loose, that will do everything you describe then run fine for a while. I had a car that would cut out ONLY on hard right hand corners....drove me nuts till I found the wire was pulling loose in that direction and not the left turns.

Also, if you have a fuel pressure gauge, check that when its running poor. I saw that you changed the filter but there is also a filter/screen in the tank on the pump that will really mess with you and cause the same problems as a plugged filter or worse. If the fuel pressure bounces around alot when the engine is revved, thats a sign of a clogged screen. Pressure should be rock solid and only drop a few lbs when revved but recover almost immediately. 35 to 40 lbs is a good number for idle. When looking at the fuel pressure gauge, everytime the needle drops, that is time that the pump is unable to push fuel to the injectors. The engine reacts to each of these "voids" in the fuel flow.
Hope this helps a little.

 

[Dog House]

John, nice to see your still around and thanks for your in put you too boomdriver. I should probably re-phrase the way this car is running. It’s not just from time to time that it acts up. Every time I start the car it usually runs bad at first then later its fine a little longer and it’s bad again and so on and so on.
I just went out and put the fuel pressure gage on it and it ran fine for about 15 seconds then went bad and didn’t come back to good again the entire time (about15 minutes) that I ran it. The pressure was good at 40 lbs the whole time. It would rise to around 44 lbs when accelerated and drop to 35 lbs when I let off then back to 40 lbs at ideal. I replaced all the vacuum lines when I got it so I don’t think that’s a problem.
I looked to see if I could get a screw driver on the ERG but with the plenum I don’t think you could depress it to see if it would die?
I’m not a bad backyard mechanic but I’m stumped especially not knowing the back ground of the car.

 

[Dog House]

Forgot to mention the car is hard to start I have to pump the gas peddle a lot to get it to start.

 

[c4c5specialist]

HI there,

I think you have a few different concerns.

#1, check your fuel injectors for resistance, 16.5 ohms
#2, check your fuel pressure 41-47 psi when you turn the key ON, engine NOT running.
#3, do you have an oiled air filter that may have contaminated the MAF sensor ?

Give your results and then we can proceed.

Allthebest, c4c5

 

[Dog House]

Already checked fuel pressure engine off key on read 42lbs after a couple minutes dropped to 40lbs and held.
To check injector ohms do you jus pierce the two leads? Ignition on or off? I presume on?
Air filter looks clean.
Might be a good idea to clean the throttle body?