Why Does It Die??

[TurboBuRick]

I bought an LS1 MAF and translator for mine thinking it was the problem and it wasn't. Not that it's a bad investment or anything but your problem could be else where. There is a sure fire way to eliminate a vacume leak. With my 87, I pulled the rocker assemblie off to shut the vales, disconnected and plugged off the PCV line and took off the EGR and selaed off the port. Then, I got a 2" rubber cap to go over the throttle body. I then took an air hose and inserted it into one of the vacume lines with about 10PSI. I know this sounds crazy, but if air doesn't bleed off, you definitley don't have a vacume leak. I hope that made sense. Unfortunatley, my car seems to have good vacum so I probably have some other problem. I would eliminate the possibilty of a vacume leak first.

Nice! Now thats the way to find a vacuum leak. I had thoughts of doing the same thing. I planned on using some soap in a spray bottle for my leak detector.

 

[darkred87T]

Yeah, that's what I did once I had pressure and I only got a slight bubbling up by the vacum block which I fixed and my car still runs like crap. However, at least now I know to look eslewhere.

 

[Rads]

Here is a run I took Saturday. I ran a temporary hose eliminating the intercooler. The fuel pressure is at 40 psi w/o vacum and at 34 psi with vacum.

 

[cool 84]

I can't open the picture but how did it run without the intercooler?

 

[Rads]

It's an Excel file. I hope that I uploaded it right. As far as the intercooler goes the car had a little better throttle responce and ran a little smoother. I can't get very good RPM's as it bogs down with out the MAF hooked up. This week I hope to go through all the vacum lines one more time.

 

[TType84]

Random thought, check this though.

Take the hose off the EGR valve and cap it off. I had a weird problem with a bad EGR solenoid and it was ****ed up and causing the EGR to do all sorts of crazy **** @ idle, sounded like i had a HUUUUUGE

 

[darkred87T]

Random thought, check this though.

Take the hose off the EGR valve and cap it off. I had a weird problem with a bad EGR solenoid and it was ****ed up and causing the EGR to do all sorts of crazy **** @ idle, sounded like i had a HUUUUUGE

Good thought, if the solenoid isn't working properly, you might have vacume on that hose at idle which will pull the EGR open allowing exuast into the intake.

 

[Rads]

Thanks for the info. I'll give it a shot and let you know.

 

[Rads]

I gave it a shot but, it seemed to make it run worse. I guess I just can't understand why when the MAF is hooked up the thing runs so bad (very rich). Just wondering could this have something to do with the O2 sensor? When I run the car for a while the code comes up saying the car is running rich. Does the 02 have anything to do with fueling or air intake??

 

[darkred87T]

Yes, the O2 sensor measures the exhaust (lean or rich) from what I understand. If the car is running rich like you say, it is very possible that your BLM numbers are high telling you there is a lean condition. As a result, the ECM will add fuel to compensate for what it thinks is a lean condition. At least, that's the problem I'm having with mine. My BLMS are 160 at idle (lean) and as a result, and the car is running rich.
Oops, an earlier Buick might not have BLM's? In any case, I would think the same principle applies where a rich idle can be a result of a lean condition.

 

[cool 84]

I gave it a shot but, it seemed to make it run worse. I guess I just can't understand why when the MAF is hooked up the thing runs so bad (very rich). Just wondering could this have something to do with the O2 sensor? When I run the car for a while the code comes up saying the car is running rich. Does the 02 have anything to do with fueling or air intake??

Have you run it with the MAF hooked up and no intercooler?

 

[Rads]

Yes, I can't drive it but I can try to get it to run long enough to get some numbers from TL. What usually happens is the plugs foul and after I clean them it runs very rich and I get alot of black smoke out of the exhaust. Thanks for the replies!!

 

[Rads]

Here is my latest run, this is with no intercooler and the MAF sensor hooked up. I checked the O2 sensor and the thing was full of carbon. I cleaned it and put it back in. started the car with the MAF pluged in and the car ran OK. Then I shut the car off and resrarted and it ran like crap again, checked the O2 again and the thing was full of carbon again. I did this several times with the same ending each time. How do I get so much carbon build-up? My BLM's at idle seem to be about 135-140. Does that sound right? Thanks!

 

[cool 84]

Ideally you want 128. The computer is adding fuel. Do you have an exhaust leak?

 

[Rads]

No, I don't have any exhaust leaks but, could my wastegat if it was leaking by cause this?

 

[Ed from Iowa]

Reset the TPS at .45, clear the computer and start it. If that does'nt work reset cam sensor. Good luck!! Ed

 

[BRAD_PADGETT]

Rads- We need to know the following numbers at idle in park We need to know:

02
blm
int
tps
iac
mal
af
fuel pressure with line off.

We also need to know every mod from stock as well. Especially what ecm, ign, and most importantly what is your MAF? You do not check for vacuum leaks with soap. This is a stupid idea. You check for vacuum leaks using carborator cleaner-If the rpm changes when spraying all vacuum lines, around the turbo as well as the exhaust manifold you have found your leak.

Until you provide the above needed info you are basically shooting in the dark at the expense of your wallet. Brad

 

[Rads]

Brad - Here are the numbers at 950 rpm with the mass air flow sensor hooked up ( the motor idles at 850 to 1150 with MAF hooked up).

o2 - 883
BLM - 128
INT - 113
TPS - .41
IAC - 110
MAF - 38g/s
LV8 - 203
fuel pressure line off - 40 psi
CTS - 147.6

I have a 85 ignition module and 86-87 coil pack. The ECM is stock 85. I am not sure what you mean by what is my MAF. The reading is 38g/s, it is a recond. unit that I just installed last week. Hopefully, this all makes sense. Thanks!

Ed - I'll give it a shot . Thanks!

 

[BRAD_PADGETT]

ED this makes all the sense in the world to me and I am only beginning to use the scan readings. I was very fortunate that a forum member -TENRIGHT and I have about 95% the same setup as him. He saw that I was struggling and took the time to come see me and he tuned my car in one hour. I watched him do it. I had the fuel pressure to high, IAC at zero and TPS too low.

Here are my numbers with a tuned car warmed up in park.

02-840
blm-123
int-128
tps-.46
iac-27
maf-05

Based on your numbers the IAC is way out of wack which affects the INT. You need to get the IAC to below 30 at idle in park. This will bring your idle rpm to 800. The other big issue is the maf reading. Way too high. I have heard through my Alky testing that only one in ten remanufactured 87MAF and after market MAF work. My experience confirms this. I am lucky that I have a good original 87 MAF. I will be switching to the LS1 type and translator in the near future. Now members can help you even more than I can because we can see what is going on. Thanks-Brad

 

[BRAD_PADGETT]

I would get the IAC fixed first which should cure the INT. If you are still having problems let us know. If it is the MAF I have a Tomco unit whiched worked on my car with the 85 ECM and I can send it to you for a test. Brad