Help! Car sputtering!

[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.

Any ideas where I should start looking?

Any info appreciated!

Merry Christmas/Happy New Year !!!

 

[not-rdy]

We're both new to the LC2 world and are going to be working on problem this weekend. Any help would be appreciated.

Thanks,
Ken

 

[Royal-T-Ltd]

I would start at the 58 psi static [no vacuum] f/p. THAT IS TOOOOOO HIGH - most peoples cars are around 43- 45 psi static; depending on chip program, injector size, boost.... START THERE.

 

[Royal-T-Ltd]

hey i just noticed you are in st. charles, thats not too far from where my brothers and i are. didnt know there were that many turbo t limiteds in this area - including rob nolans car and mine - thats 3. Would love to see your car. Private message me some time - maybe my brothers and i could help ya out as we've been into these cars for a while now - you can always learn something new though.

 

[not-rdy]

I bought this car back in March and I could hardly find pics of dark blue Regals. Now I brought in to an area where there are 2 other Blue Regal Limiteds. What's the chances??

I noticed the fuel pressure to but what baffles me is he drove the car back from the north side of Chicago with no problems but all of the sudden after sitting 2-3 weeks it started it. It seems like the fuel pressure would've acted up before that.

The car has a dual fuel pump setup but I think he said it isn't that great so he will be changing it to a 340 pump, Stock turbo, stock intercooler, adj. fuel reg., cone filter, pump is hotwired, and it has I believe 1 step up in injector sizes and not sure on the chip. I have Direct Scan on a laptop so we are going to try and hook it up and see what it shows.

I do know that these cars act up with the FP high because I had mine set to high and after driving for an hour or so it stalled on me and wouldn't restart. Had a friend pull me home and it started back up. I noticed the FP then and set it right. The car has died on me 3 times with no reason (2 times getting on it then slowing down). It seemed like the more I drove it the more dependable and normal it acted.

Strange tempermental cars.

Ken

 

[quickbrick]

if my car sits for too long it starts doin stupid stuff too i got a scanmaster if ya want to use it.

 

[Royal-T-Ltd]

If it runs good if you drive but sputters when sitting for a long period of time maybe you have a leaking injector. - had that problem - ultimately it back fired through the intake and blew out my MAF on the highway - so check for those two scenarios. and holla back.

 

[not-rdy]

Well it is looking like part of the problem is all the vacuum lines coming off the vacuum block. With Directscan the IAC numbers are high and the o2 volts are low. When we pulled all vacuum lines and blocked off the vacuum block the o2 volts went up a whole lot. The IAC is still high but at least the car went back to rich/lean switching back and forth. It was staying on lean all the time.

Ken

 

[Sader123]

Looks like vacuum leak is the ugly culprit!
All 5 circuits from the vacuum block leak. Does not matter which is connected or disconnected. O2 reading did not significantly change until ALL 5 were blocked. Also found a cracked upper intake, and a stripped bolt for the upper intake. Man, already going to be busy and I just bought the car!


Reset FP to .45, TPS was at .90 , IAC still at 74. Each adjustment we made did significantly help the idle, but vacuum was the major cause.

 

[Red Regal T]

You said it ran perfect when you got it. Due to the fact the car sits, you probably have condensation (water) build up in your fuel. Go for a couple cans of dry gas and change your fuel filter.

 

[not-rdy]

We did drain all fuel from tank and changed the fuel filter. It did idle better and run better without boost. Once boost kicked in it would backfire and go no where. I forgot about the intake but I would guess 90% of the problems are the vacuum lines.

We are getting our feet wet quickly.

Ken

 

[Sader123]

Originally posted by not-rdy
We did drain all fuel from tank and changed the fuel filter. It did idle better and run better without boost. Once boost kicked in it would backfire and go no where. I forgot about the intake but I would guess 90% of the problems are the vacuum lines.

"We are getting our feet wet quickly"




I'll second that !
I'd say we jumped in headfirst!


chris