Engine loosing power intermittently...HELP!

clusolynn

Member
Joined
Oct 30, 2006
Hello, my engine dies intermittently under normal driving conditions. Also, occasionally after stopping somewhere and turning the car off, it will not restart right away. There are no fault codes stored, and there are many aftermarket bolt-on parts. IE: Gen II, 65lb injectors, LS-1 MAF, LC-1 Wideband, Walbro 340, hotwire kit, volt booster. It sounds as if the fuel pump is not coming on when the key is turned on for the initial prime, so I will be carrying a fuel gauge to check it the next time. The car runs smoothly just prior to this happening, then with no warning it just dies at 60 mph under light load, and restarts itself, usually within 5 to 7 seconds. Any suggestions? Be nice! asloan5 is not invited to post anything!:confused:
 
Any suggestions? Be nice! asloan5 is not invited to post anything!:confused:

perhaps you may get answers if this was posted in the correct forum......General Turbo Buick Tech
or since you posted this is the engine section you should consult the guy who assembled your engine :)
 
The....

ign. control module is a good suspect for that type of cut-off. however, the maf, and a long shot is the volt-booster and gen II.
I suggest start w/ a possible loose wire, or ground on the fender near the bat, the firewall, the bat ground to block and the pos. bat.cable to the starter. If all is secure, check the maf. Not sure if the tap test will work w/the ls-1.never tried it. While your there, ck for leaks between the maf and the turbo, unmetered air usually results in rough performance, but:confused:
you can ck the ign. w/ caspers ccci simulator if you know someone who has one or a spare unit that you can borrow.(?)
Hope this helps.:cool:
 
Hello, my engine dies intermittently under normal driving conditions. Also, occasionally after stopping somewhere and turning the car off, it will not restart right away. There are no fault codes stored, and there are many aftermarket bolt-on parts. IE: Gen II, 65lb injectors, LS-1 MAF, LC-1 Wideband, Walbro 340, hotwire kit, volt booster. It sounds as if the fuel pump is not coming on when the key is turned on for the initial prime, so I will be carrying a fuel gauge to check it the next time. The car runs smoothly just prior to this happening, then with no warning it just dies at 60 mph under light load, and restarts itself, usually within 5 to 7 seconds. Any suggestions? Be nice! asloan5 is not invited to post anything!:confused:

Check your starter lead for a loose connection. Check your ECM with a known good unit.
 
First thing look at fuel pressure. Sounds like fuel pump or it's circuitry is flaky.

Do you have a fuel pressure gauge?
 
Make sure the power wire going to the ecm from the battery is in good shape. Mine was corroded at the fuesable link and would break contact hitting bumps causing the car to shut off. It would restart like nothing was wrong.
 
john I still have on my porch for a week now an auto meter fuel pressure gauge, coil pack and crank sensor...
also check to see if you have a loose nut behind the wheel. :D
 
thanks for the help Ill tell my mechanics that.I have put in so much money in this car I just hope to get it solved.I ha sent this car to high tech performance last year in los angeles,california to get this taken care of and i still had the same problem.I am supposed to send it back to them but i need more money to ship it there.I appreciate everybodys help on this site
 
It was a loose nut behind the wheel?

The starter wires and grounds all tight, all one hundred of the grounds; ground straps from S-10s, Crown Vics, BMWs etc. alot of extra grounds, but I will beattaching them in a few different places. Also, I have the LC-1 getting it's power from the ECM power lead, which I will also be changing this week. It's intermittent! the only thing I really noticed (mentioned above), I don't her the fuel pump initial bump when attempting to start at times, I think the pump or circuit has issuess. I will also be running a new hot wire circuit to the fuel pump and checking a myriad list of things, IE: loose balancer etc. Thanks for everyone's input and keep it coming, I will update if I figure it out. thanks again, John..And Albert, I tightened the loose nut behind the wheel with the wife's help!:eek:
 
How is the roller cam retained in the block? What about the cam sensor gear on the front of the cam? I assume it has the odd fire nose assembly? If so, check the bolt holding all the stuff on there. Mine came loose and I chased my tail for months trying to figure it out. The cam sensor gear would walk out enough to temporrarily stall the engine until everything lined back up. Then it would go on like nothing happened. Nothing ever showed on the scanner, fuel pressure was good, ... drove me nuts! After taking the front cover off the bolt fell out. It had been installed dry by the builder. I reinstalled it with serviceable lock tight and let it set up for a couple of days before I reassembed everything. Have not had a problem since.
 
How is the roller cam retained in the block? What about the cam sensor gear on the front of the cam? I assume it has the odd fire nose assembly? If so, check the bolt holding all the stuff on there. Mine came loose and I chased my tail for months trying to figure it out. The cam sensor gear would walk out enough to temporrarily stall the engine until everything lined back up. Then it would go on like nothing happened. Nothing ever showed on the scanner, fuel pressure was good, ... drove me nuts! After taking the front cover off the bolt fell out. It had been installed dry by the builder. I reinstalled it with serviceable lock tight and let it set up for a couple of days before I reassembed everything. Have not had a problem since.

This happened to me too. What I found is when the cam button comes loose it pushes the cam into the motor. Eventually the lobes of the cam start to hit the neighboring lifter edge causing that valve open slightly. This is magnified as the motor revs higher. The higher the rpm= the more interference with neighboring lobes.

Found mine when I took the intake off. I could see the lobes were not lined up. Not until I pulled the front cover I realized what had happened.

Stuff like this can leave you scratching.

Definitely don't want to forget the loctite on the button.
 
Thanks for all the suggestions...

It finally stalled at idle, parked in front of my shop and not 30 miles away! Didn't hear fuel pump initial prime when key turned back on, hotwire has voltage to solenoid, and when I unplugged solenoid and used a jumper wire directly to pump side of plug, pump runs! Replaced solenoid and car fired right up, hopefully it's fixed! I just recently replaced the pump, and the wire connector was brown from too much heat. It's possible the relay had been going out for some time and killed the last pump. Also, the car seems to run better; smoother at idle. If problem should re-occur, I will use the suggestions above to isolate it. Thanks again for all the responses, John.
 
still won't start

i took of the control module and hade a crack bought a new one and a new coil and still won't start:
 
Did you check...

your fuseable links? They will clear at any time. They are attached to the starter post.
 
Update...

No issues with engine dying intermittently since fuel pump relay replaced. But, since then, I have had an issue with the cam! Mine started eating into the block for no apparent reason, it has been repaired, just wanted to clarify that fuel pump relay was cause of engine dying intermittently in this case. Thanks for all the replies, John.:cool:
 
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