Help! Car won't run right!

[Sader123]

Brought my 87 GN home in november. Drove it twice the following week. Ran perfectly both times. Started 87 hr weeks until last sunday - no time to start car - it sat in garage.

Last sunday drove car and it spits and sputters now. Part throttle seems ok and has more boost than normal. At least in whistle.

Sputters at any more than light throttle and boost goes thru the roof. I do not know what boost has been dialed to , I assume approx 20psi - no guage in car.

I checked coupling at MAF and at turbo and at intercooler and at TB, thinking something maybe came loose. All tight. Fuel pressure is at 58 psi no vacuum.

Absolutely nothing on the car was changed from the last time I drove it. As it sputters it seems like it is poping back thru the intake. Outdoor temps are a bit colder than when I drove it last.

Any ideas where I should start looking?

Any info appreciated!


Merry Christmas/Happy New Year !!!

[turbodave]

Fuel pressure 58psi line off :eek: OMG, get it back down to somewhere around 40-44 line off (static) where it should be.

Your problem sounds like a couple of possibilities. Bad MAF or bad timing module (under coil pack).

GET A BOOST GUAGE!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Sader123]

Working on the boost guage turbodave !

Yea, I about freaked when I saw 58 psi - no vacuum.

Should fuel pressure be 40-44 static with stock turbo producing approx 20psi???

I'll check the MAF and timing module ASAP.

[turbodave]

Question is, how or why is the fp that high? Something go bad with the regulator? Does it have and adjustable regulator? If so try to get the fp down to the range mentioned. As for what pressure to run, if everything is in good shape and the chip is properly programmed the best fuel pressure should be in the 41-44# range no matter what injectors or setup you're running.

[ES1]

If you are running 93 octane, you should not be running 20 psi. I would think about 15psi would be max.
With boost shooting up, look for a loose or split hose.
My car is the same, I will have it running good and then let it sit and it there will be something wrong with no changes.

[HairDrier]

Sader we had this discussion in the chip forum. Unless you really really want to destroy that engine turn the damn boost down until you get a device to monitor knock and find out what chip you have.

The assclown that owned that car before obviously was nuts. I would set the fuel pressure to 43psi line off and loosen the wastegate rod COMPLETELY so you get about 10-12 psi of boost.

RUN IT THIS WAY UNTIL YOU:
1. Find out what is in this car
2. Get a scan tool, or at least a knock gauge
3. Get the car running properly

[HairDrier]

Is the service engine soon light on at all?

[Sader123]

Yes we did discuss the chip in the other forum, and I agree I need to find out more exact details of the chip, or just get another with known values. The car ran fine before for normal driving, not track driving, and I am trying to get it to run properly before I go changing a bunch of variables and get really screwed up!


Now then,......

I adjusted FP to 43psi static. Idle smoothed out and idle rpm lowered. Problem still exists even at 5psi.

I have a friend with a scanmaster coming over this weekend to check the car.

I have company vehicle, so I DON'T DRIVE THE CAR !!!
Heck I don't even have plates for it yet!
(previous vehicle at home got 500miles a year and a warm garage:-)

I have not got any service engine soon light.

In my prior experience, it seems like the timing is WAAAAAY retarded, hence the quick spool but lack of power. But there is also a large hicuuup and a pop back thru the intake. Ignition???


I can spin wrenches but am new to the TR, I am still playing catchup.


Thanks for the replies guys.

Hairdrier - the chip was the first thing for me to remedy, but this problem just poped up after I started researching the chip.

[HairDrier]

Your problem could be ignition related, but it is too early to tell. Too bad your buddy doesnt have Turbolink so you can record the data, but a Scanmaster will help.

An excessive lean condition could cause fast spoolup and a backfire also. Let us know what your BLM and INT #s are when you get a scantool. Also check the O2 cc's to make sure your O2 sensor is cycling and operating correctly

When I had a similar problem it turned out to be a bad ignition module, but your problem may be different. Let us know what you find

[Sader123]

Adjusted TPS to .42 from .90

BLM 150
INT 128
O2 xcount 46 12mv
rpm800
spark adv. 23.9
MAF 8
TPS .42
IAC 94-95
A/F 15.3(was at 14.8 with TPS at .90)
Inj. pulse width 4.3-4.0.
Now I get constant code 44.

[HairDrier]

Is this in park at operating temperature? If so your IAC count is WAY high

BLM of 150 indicates WAY lean, and your code 44 is for your O2 sensor detecting WAY lean.

Sounds like you may have an air leak somewhere, like the plenum gasket or intake gasket. I would change the O2 sensor as well, since they are cheap just to eliminate the O2 as a possible problem.

A plugged injector could also be a problem

Check all your vacuum lines for leaks also

[Sader123]

Pumped out all the old gas and put in fresh Mobil 93, changed fuel filter, sprayed intake and vacuum hoses with carb cleaner - no change in idle. O2 sensor is a new 3 wire sensor.
Service engine soon light soon has gone off but code 44 still shows up on directscan and direct scan shows under part throttle driving that O2 sensor is switching back and forth lean/rich.

What is IAC???



Engine is at operating temp (185-195) for all readings.

At idle we can hear popping noise inside hedders.

[Sader123]

Last reading was BLM of 150
INT150
O2 xcnt32 35-39mv O2 readings between approx.200-600+ part throttle
rpm 900
A/F 14.8
MAF 6
IAC 87
inj.PW 3.7-3.9

Is a lean reading correct?
How can it register 150(lean) with A/F of 14.8 ?
What should A/F be closer to?

[HairDrier]

Forget the a/f for a minute, and find your air leak. I bet you have a bad vacuum line somewhere causing your car to run bone lean. If you dont find a vacuum leak then spray some starting fluid at the base of the intake manifold, up pipe seals and plenum base. If you hear a change in the idle of the car you have found a leak.

BLM and INT readings of 150 means that the computer is at its limit as far as adding fuel and it STILL cant supply enough.

IAC is your Idle Air Control Sensor. It is WAY off but I dont think that would cause your lean problem. Here is the procedure to get your IAC and TPS where they should be
http://www.gnttype.org/techarea/faq/IACresetscan.html

[Sader123]

OK! Finally got somewhere!
I unplugged all 5 lines from the vacuum block.

Hairdrier - You were correct! With all 5 lines disconnected my O2 readings shot up - fluctuating beteween 300-700. O2 also switching back and forth from rich to lean - all at idle.

Also found one intake bolt loose - probably stripped, and one crack in the upper intake . Above readings were just with vacuum lines off, did not matter which lines were on and which ones were off. They all leak - somewhat!

Miss is now less and idle quality has greatly improved.

Next;

IAC still around 74 and screw is adjusted all the way out - no more adjustment left.
What gives?
How does the ECU measure IAC counts.


I will tell you the Direct Scan was invaluable - without it I would be LOST!


As soon as I get enuf coin I will get a directscan or turbolink for sure !!!

Thanks for your help, I'll post results as soon as I fix these prob's first.

[HairDrier]

IAC still around 74 and screw is adjusted all the way out - no more adjustment left.
What gives?
How does the ECU measure IAC counts.


:add_schac You are turning the screw the wrong way, clockwise lowers the IAC count :arco:
This will throw off your TPS also, so you have to alternate between each one and they will come in line. I try to set my IAC around 10-15

The IAC count somehow represents how much air the IAC motor is allowing into the engine at idle and part throttle. If off it will cause hesitation and stalling when you let off the gas.

Do yourself a favor and take $25 to Autozone and buy enough vacuum hose to do the whole engine. You will need a few different sizes and do one at a time. Then buy some zip ties and zip tie all the hoses to their connectors so they dont blow off under boost. You will probably have to reset your FP regulator once you get the vacuum lines fixed.

Glad you found the problem and it was cheap to fix. Now you know why us jackass's first question is always "do you have a scan tool?"
:add_wegbr

[Sader123]

OK got the IAC screw going the correct way - it's been a long day!

How do you adapt to the hard plastic line???

Also is that 24 degrees spark timing too much at idle?

[six shooter]

OK got the IAC screw going the correct way - it's been a long day!

How do you adapt to the hard plastic line???

Also is that 24 degrees spark timing too much at idle?
To repair damaged hard plastic lines, cut out bad section and slide some 5/32" rubber vac. line over it . Zip tie ends to secure.

[Sader123]

To repair damaged hard plastic lines, cut out bad section and slide some 5/32" rubber vac. line over it . Zip tie ends to secure.


Will that be enuf to hold boost ?

[six shooter]

Will that be enuf to hold boost ?
If not , apply a little 3M Super weatherstrip Adheasive to the side of the plastic line before sliding it in the rubber hose. It will never come apart .

[not-rdy]

Today was definitely a valueable experience for me. We did a lot of searching and it was nice to find the culprits. My car was ignition switch(brand new) and battery(brand new) that gave me fits right after purchase. Chris's is vacuum lines and intake. This spring should be fun. Spring cleaning and some custom fabrication and we will be on our way.

Ken

[HairDrier]

Its cool that you guys can butt heads and help each other out, I know no one around here :albert:

Plus you can share parts to help diagnose problems, as well as tools. I have to buy everything, but most of the junk can be used on other things so that helps.

Sader dont forget to check the WOT TPS setting, make sure it is over four volts at WOT or the ECM wont go into power enrichment mode.

[1badTTA]

Just a suggestion, but you said FP was at 58psi originally and you set it down to around 43psi. Then it was running really lean and you were looking for an air leak.

Try using as different gauge to make sure on the fuel pressure, and make sure you have the correct chip for your injectors. Since the car is new to you, assume nothing and check everything. It is possible it is a chip for 50lb injectors that used to be in the car before you bought it but got removed and they just cranked up the FP as a bandaid. Or the fuel pressure wasn't really 58psi and the gauge is jacked.

[Sader123]

Is the WOT volts on the Direct Scan?
And I assume I would have to get WOT volts over 4 while keeping TPS at .42?

I definitely discovered the FP guage is off. Shows 5psi while holding it in my hand. A different guage shows it is off 5psi thru the whole range. I need a new guage!

Chip says "green top injectors" I tried to scan the chip in but pic quality is poor. Sitcker on the chip is hand written
word for word:

" Street performance
GRN-TOP INJ.
.207IR
25* @'M RPM "

I assumed 25* was total but after direct scan shows timing at idle 800rpm, to be 23.9, maybe that 25* is 1000rpm? Also hard to read I assumed the degree symbol because of its placement. The '@' symbol is also assumed, written too small with felt tip - ink spread together, but is close to assume. Last symbol ' may be a "1" but looks like someone tried to squeeze it in there - didn't leave enuf room for themselves.

So after yesterday's lesson, My injectors are completely black. Chip seems to make more sense after seeing readings.

What is the .207IR, sloppy writing, could it be .207IP ?

[HairDrier]

Take the numbers off your injectors and look them up at www.gnttype.org. That will tell you what injectors you have. I suspect they are stock or 30# stock replacements.

That chip has me clueless. Like I said before if it is 25 degrees you will be putting your rods throught the oilpan in no time on pump gas.

Once your car is right make some recorded runs on Direct Scan and post the results. The someone familiar with DS like TurboDave or TurboBob can help you decipher them

Keep the boost low at first, and then work it up to 15-16psi and see what happens

[HairDrier]

Do your injectors look like this?
These are 009's

http://www.gnttype.org/techarea/pictureguides/injectors/425lb.html



Here are other part numbers for injectors
http://www.gnttype.org/techarea/fuelsystem/injflow.html

[Sader123]

Well, On such a beautiful day, 71*F here in St. Louis, I decided to play hookie and see if I could get to the bottom of my problem. Went to the local auto parts store and bought a bunch of vacuum hose. Replaced all vacuum circuits with new hose - fixed now right?

Negative!

Still sputters........

SH*^!!!!!!


Light throttle driveability has greatly improved in that I
can now have about 1/4 throttle without sputtering and it "almost":) sounds normal. Any more throttle and it sputters.

Got my Mityvac and started to test each individual circuit.

FOUND! EGR solenoid does not hold a vacuum. Is it supposed to? :fragez:

FOUND! Charcol canistor solenoid does not hold vacuum. Is it supposed to? :fragez:

I don't know! :SHOCKED:

I bypassed these circuits(capped them off).
Driveability again increased. But still sputters going up slight incline. AW HECK!!!!!
I must be on the right track as each find yields an improvement. Car is still miss firing on the lean side. And my friend with the Direct Scan is not available to help today. Well a little light goes on..............

Like I mentioned earlier, today was a beautiful day for the second day of 2004, so I figured I'd put my new GSS340M pump in to get ahead of the game for spring.

I removed what I assumed was the stock in tank pump - looks like GM markings on it and removed an older Bosch external pump.


After checking for leaks, I immediately noticed there was no more popping at idle in the hedders and it was smooth.
What the hell, I had nothing to lose, so I went for a drive.

MAGIC!!!!!! IT RUNS AWESOME AGAIN. :top:
MUST HAVE BEEN ONE OF THE FUEL PUMPS WENT OUT.
When I pumped the tank out last weekend I thought it was slow moving and this confirms it!!!

Sorry for the long post, I am excited my new toy has sprung to life again!

I WANT TO EXTEND MY THANKS TO THOSE WHO GAVE INPUT TO THE PROCESS! IT IS VERY MUCH APPRECIATED!

Does anyone know if the two soleniods listed above should hold vacuum? I hooked one of them up on my drive tonight - still 68*F - and the car still runs fine.

......now to get back on the pesky chip situation..............

Thanks again guys!

Happy New Year to all !!!!!!!!