The message to which you are about to reply is shown first. GO TO REPLY FORM



 VIEW    REPLY TO THIS MESSAGE    PRINT   SAVE 

RPM's fluctuating on their own when holding above 3K or when entering boost, also strange noise heard 700 1987

posted by  someone claiming to be 740TurboPerformance on  Sun Dec 7 13:55 CST 2003 [RELATED]

Thought I'd come by say hello and see what you guys thought about this problem


I drove my girl to her moms house and it had plenty of power, boosted just fine, past 4,000RPM unbelievably smooth, then when holding my foot near full throttle I see the RPM's start to jump up and down from 4,000RPM to 4,100RPM and the vehicle surges a bit.

I had the window rolled down and tried it again keeping my foot on the gas, it is crazy you can hear a fairly loud popping or tick tick tick tick tick noise when it does it from the engine compartment if you roll the window down and its doing it. I don't know if its detonating, misfiring or there is something mechanical wrong inside the motor (I'd hate to believe so because it runs so good otherwise with lots of power). You can only hear that noise when the window is rolled down and will only make the noise if you keep your foot on the throttle as the boost gauge enters boost. Driving normal out of boost it doesn't tweak at all however I just started it tonight, let it warm up and when holding the throttle at 3,000RPM it started to do it minus the strange noise I heard when driving and entering boost when it was doing it. The RPM's flucated a bit more wildly when parked and holding the throttle.


What the heck is going on............? That noise has me a bit concerned, it doesn't do it at idle so I don't know. At idle I started jiggling the wiring harness around, IAC wire, Hall Sensor Wire, AMM/MAS wire and it keeps idling fine at the same speed.


I noticed that the Fuel Injector Resistor pack looked like it wasn't in the best shape, some of the wires were just a tad frayed coming out of it but they all seemed to be connected fine and making connection, this and the knock sensor are the only things I am really figuring it may likely be at this point. I guess it could also be the Hall Sensor, I hope not, I just paid the Volvo shop I go to, to have the Distributor resealed, Cap and Rotor replaced.


So far I've replaced the Idle Air Control Valve, Ignition Module, cleaned the connectors, grounds, new Spark Plugs, Wires, Ignition Cap and Rotor, newer Wiring Harness seemingly in good shape (old one was shorted), new Intake Manfold Gasket, new Vacuum hoses, cleaned Throttlebody, new Turbo Hoses, new Air Filter. I tried another AMM/MAS today that was working that I had kickin' around. I tried a new Fuel Pump Relay, the Fuel Pressure Regulator is new. The previous owner had replaced the Fuel Pump and ECU with pulls from slightly newer lower mileage Volvos. I don't know................ I need some help and would really appreciate it, thanks...........!






USERNAME
Use "claim to be" below if you don't want to log in.
PASSWORD
I don't have an account. Sign me up.
CLAIM TO BE
Use only if you don't want to login (post anonymously).
ENTER CAPTCHA CODE
This is required for posting anonymously.
OPTIONS notify by email
Available only to user accounts.
SUBJECT
MODEL/YEAR
MESSAGE

DICTIONARY
LABEL(S) +
IMAGE URL *
[IMAGE LIBRARY (UPLOAD/SELECT)]

* = Field is optional.

+ = Enter space delimited labels for this post. An example entry: 240 muffler


©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.