please help!

[Trydon]

hi, i have a 91 sho+ mtx. the problem is that it isn't running right. the problem just started this week and has gotten so bad that i can't drive it anymore until i fix it. if there is no load on the motor(not driving it), it seems to rev fine(most of the time) except sometimes when idleing it will drop to around 500 rpm for a couple seconds then go back to normal. but when there is a load on the motor it starts missing really bad (especially at full throttle). its kind of hard to describe, but it seems like it wants to die, but it won't. it acts like a couple of cylinders drop at the same time. i thought it could possibly be the camshaft position sensor maybe? i know the cams are good. it acts like it is something electronic that has to do with the timing. i think. it doesn't backfire or anything, it just doesn't want to go. the check engine light is NOT on. although sometimes it will come on for a second or two when driving down the road, but it goes right back off (it has always done that). i ran a diagnostics test on it and the only error code that came up was 24 for the act sensor, but i don't think that is the problem. can someone please help?

 

[Bizzy]

Ok...first things first. Does the tach ever drop to 0? If not then it's not your CPS. The idle issue could be caused by your IAB. Check out this article for info on how to clean it.

One more suggestion, re-check your codes. Run both the KOEO and KOER tests. Look here for more information on how to do it.

I hope this may be of some help. Welcome to the forum.

<small>[ October 19, 2002, 11:40 PM: Message edited by: Bizzy ]</small>

 

[BeatDaSHO]

check your plug wells for oil. It sounds like they might be full of oil and causing misfires in the cylinders. pull off the plug boot and take a look.

Greg

 

[Mike Kopstain]

BeatDaSHO:
check your plug wells for oil. It sounds like they might be full of oil and causing misfires in the cylinders. pull off the plug boot and take a look.

Greg

Ditto. Very common problem. Even if there aren't any traces of oil, pull the plugs and look for arcing up the insulator.

 

[Trydon]

hey, thanks for the suggestions beth, my tach doesn't drop to zero so it must not be that. i did only run the koeo test. i'll run the other test and see what comes up. thanks

 

[Trydon]

hey, yea i already checked the plug wells, they are clean. besides, i just did the 60k, including new plugs and wires and siliconing the well seals. thanks for the suggestions though

 

[Trydon]

o one more thing i forgot to mention. it is getting horrible gas mileage like this, about 5 miles to the gallon!

 

[Trydon]

i now think it could be either the throttle position sensor or the crank position sensor. i think it could be the tps because i ran the koer test and one of the codes i got was 73 for the tps, however i did not get any codes for the cps. do these sound like the symptoms of a bad tps? please help!

 

[Trydon]

screw it! i give up. any one wanna buy it? $1000 for a 91+ jewel green/mocha mtx. needs that problem fixed and exhaust. 140k on car i am done with it! i have had nothing but problems with it ever since i bought the car! $1000 any takers?

 

[DAMNMYSHOTOHELL]

Sounds to me like you need a new motor Trydon. Your Welcome for the help. Oh yeah, thanks again for the tip on the clutch. thumbs_u thumbs_u

<small>[ October 20, 2002, 08:01 PM: Message edited by: DAMNMYSHOTOHELL ]</small>

 

[projectSHO89]

Rerun the test. Goose the engine harder during the goose test.

Your posted symptoms do not point to a failed TPS or a failed CPS.

Pull the vacuum line from the fuel pressure regulator and see if there is gas or a gas smell in the line. If so, replace the regulator.

The SHO boys are always on the lookout for a "steal" that needs fixin...

Steve

 

[luigisho]

Even if it is the tps it only costs like $15 at AutoZone. Why give a car away over a tps?

 

[Trydon]

yeah, i dont think it is the tps and there is no gas or gas smell in the fuel pressure regulator, so i am still stuck. anyone have any other suggestions?

 

[Trydon]

o yeah, and to DAMNMYSHOTOHELL, u r welcome for the tip on the clutch. thumbs_u

 

[Trydon]

could it be a vacuum leak maybe? i've looked and can't find one, but it seems like it could be something like that or maybe something with the fuel system. i recently changed the fuel pump and filter. so i don't think it is either of those, but maybe something else in the fuel system. if i don't figure it out i am going to sell it because i am tired of the damn thing.

 

[MilTownSHO]

Wanna trade for a different 91? I'm in Milwaukee. I also got a parts car. Interested? Let me know

 

[SHOZ123]

Trydon, my '93 is doing the same thing. Does the tach read low at highway speed?

 

[BeatDaSHO]

Hey DougLee25.....wanna buy it? thumbs_u

Greg

 

[Trydon]

no i don't think my tach reads low at highway speed, but i don't know for sure because i haven't been driving it like this.

 

[Trydon]

yes i am interested in trading for another 91. what kind of shape is it in?