I've got a 90 RS 305 and recently started having trouble. My car died the other day after I put it in reverse just after starting it (seemed like I lost all pressure somewhere and it just sputtered for a second and died).

Today, my car would surge when running. When at a light it began to surge and i felt a slight knocking (it was consistant, every 3 seconds or so). Driving seemed fine. I felt it surging still at low speeds and found that at idle from a dead stop it kept getting more powerfull until I was going about 30mpg w/o having hit the gas yet.

In the driveway when I had it in park I can feel it surging. It went up to about 1500 rpms without me ever hitting the gas... then it suddenly went back to normal (about 500rpms). A minute later it went jumped back up to 1500 rpms and I could feel it rev.

Any ideas? I just replaced the EGR tubing and valve, but I checked it for leaks just in case and didn't find any.

Jm

 

possibly the torque converter, i had a similar problem to this on my old grand am and it turned out to be the torque converter.

 

i would suggest looking for the vacuum leak after mesing with those vacuum lines witch tend to get brittle over time and those hard plastic lines are somewhat notorious for hiding thier cracks also running the trouble codes may be a help to narrow down the problem,,don

 

when i replaced my EGR valve it did that...i could do almost 30mph without touching the gas. I had forgot one of the vaccum lines onthe valve. Double check it because thats exactly what mine did/.

 

I will about guarantee that it is a vaccum leak. I just had that same exact problem. Same symptoms and everything.

The first thing I would check is a vacuum leak. Or maybe a vacuum line came off.

 

I checked the following lines:

The EGR line from the solonoid to the EGR valve.

The second EGR line from the solonoid out.

The EGR valve line to the carb. (longer line)

and the 4th small plastic line.

I also checked the other line on carb near the one from the egr, I think it ran to the air r

I checked 5 lines total. I also checked for the hell of it the vaccum on the part that has a little valve off of the air filter housing. It too had suction.

Is there anything else I can check?

Thanks,
Jm

 

just for shoots and giggles this may sound odd but were you operating the heater or air conditioning when this happened/ if not anyways open the hood and watch the a/c clutch see if it is kicking in every so odd seconds this happenend to a friend of mine but it just slipped my mind to mention by your description,,check with the heater on and off a/c on and off giving lets say one or two minutes on the on cycle and off cycle each to see what happens i recall this as also showing no trouble codes when this happened to him it was most puzzling

don

 

AC was on when it died in rev. Only died that one time (prolly' cause I threw it in reverse 'just after starting).

Car always surges a tiny bit w/ ac on. But this was doing it w/ ac off too. Didn't try heater. I do know that my AC compressor kicks in and out on sched, but if I use anything above the lowest setting on "MAX A/C" on the controls it sticks... I watched until it almost started to somke. Normal works fine, no sticking. Low freeon, bad compressor, I donno, never looked into it.

Funny thing. Friend of mine is a mechanic and I had a chance to let him see what was wrong. I started it up and nothing. No surge, didn't die, didn't run heavy. Drove around town and still nothing. So for now I guess it's okay... so I'm really thinking I have a leak somewhere.

jm

 

Check the lines to the evap cannister, if you still have one.

 

Check your O2 sensor and TPS. Had a similar problem and my O2 sensor was bad, but the TPS could be searching for the idle speed and unable to read the signal from the ECU.