No power? Shaking/bogging at 1/4 throttle?

[ryan95eclipse]

I am about to purchase a 98 spyder gst with 90k on it this weekend for 250 bucks. From the pictures it is clean as hell. But the owner has said the car idles great, doesnt smoke, doesnt leak nor over heat. BUT when he gives it abut 1/4 throttle it like sputters and shakes. the car idles and drives fine on a straight flat road but during an incline it does the same thing... Any ideas? Ill be getting it during this week or waiting to have it dropped off on the weekend. Opinions would help a lot! I would love to keep this car.

 

[force_feed]

That could be a number of problems.
fuel pressure
boost leak
faulty tps sensor

 

[pazsion]

yea a number of things to check

mfi relay or multiple purpose relay

check all battery connections and grounds and the battery clean them.
make sure all wires are in good condition and not cooked.. they bend with no cracking sounds.. no stiff points..

in wireing an old voltage regulater i had to patch the ignition wire and mfi wires.. these go to the alternater, mfi and computer.. and will cause bogging if shorting or loose.

listen to the car while running and push the thottle.. any whineing from the alternater is bad, fluctuateing lights, like those on the dash or lights on the rear view mirrior are particularly sensitive to this..let it shine on your hand and watch for dimming..or brightness..


replace the 02's check the throttle seonser and the idle air control.. make sure they are tight and not loose, and function properly.. replace the map sensor.

check the coil, plugs and wires..buy new ones..

This is what i did when my talon did the exact same thing.. changeing the coil plugs and wires made a big diffrence..i also got a computer just to be sure..

I also had a clogged injecter on top of all that..

ran some stp fuel treatment , water remover, and octane bootser.. cleared that up...

Make sure the timing marks are where they should be...!!

if these are off a bit, the car may run at speed, but funny at idle, or under throttle as well.. maybe even sound like it's detonateing. my timing belt slipped and caused a similar situation as well..

So many things to check.. but WELL worth it.. espeacially timing.. if thats not checked and you continue running around, it will slip more.. thats your valves and pistons dude.. save yourself $1200+ and check this carefully..

check compression..

 

[eclipsegsx224]

Is it smoking when your giving it gas ... saying your getting more fuel then air if so its deff. a boost leak

 

[chanley talon]

Sounds like junky plug wires.

 

[jb2zero0six5]

new plugs, boost leak test.

 

[crusada]

well either way if its way clean for 250 bucks for a spyder gst you cant go wrong . Awesome find man.

 

[eclipsegsx224]

ya deff agreed you could part it out worst care senerio and still make alot more than 250

 

[cliffkemp]

another thing to check is the connectors at the FIs. I had one that was not quite snapped on just right and would randomly lose its connection and it would be running on 3 cylinders. usually, it would 'disconnect' when accelerating or going up a hill as you suggested. all other things should be checked as well too.