help,86 g.n runs like it has a rev limiter

[turbocaddy1982]

hello,i have an hybird,1982 caddy coupe deville,86 g.n. motor and trans,has 190,000 miles on it and never any problems till now...when i take off from a light or just rev it up in park or neutral...the eng sounds like it has a msd rev limiter in it...can't be a miss because it is not always there...fuel pressure at the rail is steady...any common problems...p.s. lately just today the car started cold and stayed in a high rev for a while before coming down on it's own...the popping sound in the exhaust..i can hold it at that speed and it will continue to shake and pop..new plugs,wires,tested a new maf...any ideas?

 

[Quick6'n'-K.C.]

Coil pack and module or the cam sensor is going out.
Usually if the cam sensor goes out, once you shut it off the car wont start back up.
Coil pack and module can be purchased from Red Regal T in the parts for sale section for 50.00

I have a coil pack and module tester from caspers, it gets alot of use here in KC... I bust it out twice a week testing it on various cars that buck,cough,spit and run like arse...

BW

 

[RUQWKNF27]

My car wa sjust doing the same thing .. It would go to 4300 rpm's an just stop.. It was the Ignition Module.. I did notice sometimes on cold start it would idle real high then come down.. Bought one @ Asvance Auto for 76 bucks with lifetime warranty... Its not GM but it works for now!!!! Also OHM out your coil an make sure all post are between 11-13 ohms. Ohm it out front to back!!

 

[turbocaddy1982]

i will try that.... i ohmed the coil frt to back..got 13.o-13.1...both items are about 30,000 miles old....could be bad.....i have a spare somewhere....will get back to u guys....

 

[turbocaddy1982]

strike one, changed out the module and coil...ran good for a while like 1/2 hour then it came back.....i wonder if the crank or cam sensor would do the same thing intermittinly...i do have an oil leak in the front that might splash on the crank sensor....or maybe the turbo...seems only in the first take off..

 

[turbocaddy1982]

OK, after months and money spent chasing the problem...and dealing with it as my daily commuter..the problem surfaced itself...like i hope it would of...no check eng light or codes of any kind...the last symptom was an intermitt no boost past 5psi on the highway....then it went away ok...then just the other day...my oil light came on solid...I checked the oil level was fine.....started it and checked my oil pressure gauge...was fine and went to 60 psi when reved....replaced the oil pressure switch to solve the oil light problem and now she runs great.....remember the switch is a 3 prong switch,it also controls the fuel pump incase the eng oil pressure drops or incase of an accident and the eng stalled out the fuel pump won't keep pumping to fuel a fire...the switch must of been cutting my fuel supply at the rpm's that it always did it on..remember if i floored it past that point it went fine....i was looking at the rpm point and not the oil pressure point at the time of the stutter....hope it helps some of u folks out...it was not the maf,coil,module,tps,cam sensor,was thinking of a crank sensor ,but that works or does not work...even with 195,000 miles on it she flies like she's new.....turbo to ya!!!!!!

 

[DavzGN]

The oil pressure switch is only a backup to allow starting if the Fuel pump relay failes. Assuming your fuel pump relay is good, it will not kill the fuel pump if the oil pressure is low. I don't know if it would affect the Fuel pump if your fuel relay is bad.

David
87GN

 

[turbocaddy1982]

got it to run 2 god and now blows out the trans

 

[rodman99999]

The oil pressure switch is only a backup to allow starting if the Fuel pump relay failes. Assuming your fuel pump relay is good, it will not kill the fuel pump if the oil pressure is low. I don't know if it would affect the Fuel pump if your fuel relay is bad.

David
87GN

Correct- The oil pressure switch is also a bypass for the fuel pump relay, if it goes bad. If both are bad- no voltage to the fuel pump. It wouldn't just run poorly. It wouldn't run at all. Further: If the engine isn't running/doesn't start- the ECM cuts the power to the fuel pump after 4 seconds(fire prevention,etc.). Sorry to hear about the tranny issues!!