Surging on 90 sho

[tracer1315]

New to this site and cars in general other then driving them. Trying to learn on my 90 sho. It has 112,000 miles and when i start it the engine surges and i see the headlight dim and brighten a little but nothing else that i can tell. someone told me it was my MAF, so i replaced it and that just ended up being a waste of money. Anyone have any suggestions?

Thanks

 

[Vnuk1]

Here use this link to check for Engine codes so we can help diagnose your problem better and post the codes here.

http://www.shophoenixproject.com/eec/eec.htm

 

[Kens1992mtxSHO]

I would pull your codes and tighten every ground wire you've got. Don't forget the black grounding strap on the back of the intake (pass side)

 

[Vegasho]

I have a 1993 sho mtx and it had the same problem and it ended up being the rubber boots on the intake manifold where loose and all i did was tighten up the clamps and it was fine so try that first.

 

[shobote]

So headlights are probably brighter as the engine speed goes up, dimmer as it goes down. Check for vacuum leaks on intake. Being a newb to car fixin, you can go broke buying parts just guessing a problem based upon uneducated opinions; MAF's usually do not go bad either, just require cleaning the filament.

 

[93rev2sev]

Get an 8mm nut driver.

Tighten everything it fits.

 

[tracer1315]

Thanks guys i will try everything tomorrow and let you know how it goes.

 

[tracer1315]

Ran the codes, it said that it was a 73 which is the throttle positiion sensor, went ahead and replaced it so hopefully the problem will stop.