SHO running rough and not enough power

[91 shonice]

HELP! I've had it up to here I've got a 91 and it dosen't have the power it should have. Its been gradually getting worse for the past 6 months. I thought it would be the exhaust or clogged cats becasue the car kept going putt putt putt, so I had those replaced with midwest y-pipes and dynomax exhausts. This still didn't fix the problem.The car idles at 800 rpm's and secondaries open at about 2800 rpms. The car eats up gas like crazy also. Somtimes it works and I have full power, but that dosen't last long. I'm stumped I spoke to some mechanics and they said that it may be no fuel pressure and I should change the pump. Another person said that I should change the injectors. HHHEEELLLPPP.

I really respect your thoughts and you've helped with many problems that I've had by other posts. If you could please help me out. I'm just an everyday backyard sho mechanic.

 

[SHOtime2511]

you need to get your EEC codes pulled Autozone,Advance auto both do this free of charge,of you can buy a nice code puller at Wal-Mart for around $35.00 it comes with a nifty book to tell you what each code means,if you post you problem codes here on the forum it will give us a little more to work with when it comes to what wrong with your car

 

[Redline]

Or you can pull them yourself for the cost of a paper clip:

http://www.midwestsho.com/catalog/troubleshooting.php?codes=instructions

Hard to say what your trouble might be without codes. It could be a number of things including: oil in the spark plug wells, the wrong spark plugs, a bad coil, bad plug wires, incorrectly connected plug wires, a dirty MAF, any combination of the above, or something completely different etc.

 

[91 shonice]

Okay, ran codes KOEO and got code 46 which is DIS module, think I should try replacing that? Also, when I ran KOER all the sensors where all out of range. but thats because the cars running rough. I just had a complete front engine maint. at NESS and changed all the sensors. Fred was very good at explaining everything.

 

[SHOtime2511]

id also check the coil pack before i changed the DIS
http://www.shoforum.com/cgi-bin/ult...c;f=17;t=005873 HOW TO
then id be looking to replace the DIS

 

[91 shonice]

So I changed the coil pack and now the car is running much better. But I still have the issue of the car running with some power to running fine. It seems that the car runs at less RPMs but then I'll see the tach jump up and down then run fine. ...

Could this be a fuel pump problem because of pressure loss. Do I change the fuel pump?

Stumpped

 

[ycode90]

I had a similar problem, I thought it might be the fuel system, then maybe the ignition system. Turns out there was a problem in the computer. I changed it out, and never had another problem.

 

[kurtis adum]

is there ne oil in ur plug well?
kurt

 

[slapnpop]

I haven't seen anyone mention the fuel filter yet. If you've got a large particulate clog that's working it's way in and out of the restriction, it could cause just this behavior. Except for the horrible gas mileage, mabe.

 

[Venom SHO s7]

If you can, swap the DIS for one you know works fine. My car had similar symptoms, ran fine one day, then like **** the next, and tach would act funny too. And you said you got a DIS code too, so its worth giving it a shot.
Just to make sure, check that you have the right firing order and that the plugs are threaded in right and your wires are making full contact at the coil and at the plugs.
good luck

 

[Fastball]

Damn, this sounds exactly what my '91 started doing last week!

Since the tach was jumping all around and I didn't get a "check engine" light I thought it just went through another cam position sensor. Replaced it with a new one from Advance, but the problem is still there.

When it does start running like garbage it sounds like I am driving an old VW. I plan on doing the plugs and wires today!

 

[ROB S]

Oil in the plug wells? New(er) wires? Failing ignition components will rob you of serious power.

If the car sounds normal but just has no power try unplugging the MAF and going for a drive. See if that eliminates the problem.

 

[Fastball]

OK, reviving this post a little.

I changed my plugs, (no oil in the wells), put on new wires, changed the fuel filter and went and bought the code reader from Wally World. Still running like garbage when it feels like it, then runs perfect.

Ran codes; KOEO 11, great; CM has a code 46 stored in it, (Coil 2 primary circuit failure); KOER 11 great again, I guess.

I really need to figure out if it is the coil pack or the DIS module. I know of no one else with an SHO to do a temp swap. I have tried to access the above address to check the coil pack, but it just takes me to the Forum Home page. I have done an Advanced search for the title and for member "projectSHO89" and come up with ZILCH on checking the coil pack.

Need some quick help here guys, I'm taking the family to VA Beach next weekend and need to take the SHO.

Thanks,
Big Dave

 

[Jaz2099]

BTW, advanced auto or autozone will check things for you like the DIS, etc.....

 

[Fastball]

Yes I had heard that and went over to them on Sunday. The guy with the ohm meter knew less than me when it comes to electrical....and I don't know Jack! He said it's easier for them to test them if they're off the car.

Anyway I asked him to check the availiblity of the DIS & coil pack. Much to my suprise they had a coil pack on the shelf. I asked him if I bought it, took it home, put it on immediately, and if it didn't work could I bring it back. After all most places clearly state, "no returns on electrical items". To my suprise he said sure just don't run it for a week and then return it. Well it took me 20 minutes to install & reset the idle and discover it wasn't the problem. So I put the old one back on, plus removed the DIS modile to take in so they could test it off the car, as he mentioned before. Guess what, their machine doesn't test this type of ignition module! Perfect!!

Well it HAD to be the problem so I had him order the Wells F147 with the Lifetime Warranty. It came in on Monday afternoon and I installed it Monday evening. Drove it to work today and she ran perfect!!

Since the oil has got to be full of gas, I'm just waiting for the SHO to cool down enough so I can go change the oil and filter. She deserves a fresh drink of Mobil 1 and some apologies from me for all the nasty words I said to her over the last week.

Now if my Traction T/A's would just get here I'll be all set for the trip to Virginia Beach!!

Later,
Big Dave

 

[kurtis adum]

glad to hear ya got her goin good cheers
kurt

 

[Joe'sSHO]

I'd be willing to bet that this is a DIS problem. When my DIS wasn't grounded my SHO was behaving exactly the same. Like others have said, try finding someone with a running SHO and swap in the working DIS. Sounds like the DIS to me though, esp. with the DIS code.

 

[Fastball]

Uh oh, I smell a money pit starting to grow.

Got my T/A' s on last night and on the way home my water pump took a dump!!

I am still suppossed to leave for VA Beach on Sunday!! God this makes me love my motorcycles even more!!

Now for a thread search on waterpumps.....

Big,(P.O.), Dave