Help: Severe Bogging down/sputtering with >1/4 acceleration

[ronhawaii]

Have a problem with my 91 Laser 2.0 Non-Turbo with auto trans and 80,000 miles that I hope someone here can help me with.

Current problem occurs whenever I press the accelerator more than 1/4 of the way which is basically all of the time right? When I exceed the 1/4 mark on the accelerator the car badly boggs down and sputters something terrible. As soon as I ease off the throttle and press it less than 1/4 power, the car gives no indications of a problem. If for instance I lightly press the accelerator from a dead stop the car has no problems and will accelerate up to highway speed with no problem at all, just takes a while to get there. Now, if I press the pedal more than 1/4 of the way, forget it!! It may also be worth noting that while sitting at a stop sign or in the driveway etc, pressing the accelerator with the car in park or neutral and reving the engine, the RPM's progress smoothly throughout the entire range with no sputtering etc. So, it only seems to occur when the car is under a load. Also, this problem definitely seems to be an engine related type of thing and not the transmission.

Ok, so what have I done to the car recently?

Well, about 2 months ago, the car was just running generally like crud. You know, not as much pep and and crazy idling. These symptoms came on slowly over time and I really didn't mess with it until it would not start at all one morning. Engine would crank but no start. Bench checked the starter and it was good. Battery, good. Spark, good (as far as I could tell, I could see spark during testing but cannot testify as to strength by just looking at it). So, looked at spark plugs. Looked like they needed to be changed so I did. Used Bosch plugs (Ok, don't kill me). While I was at it and since the car hadn't had much TLC in quite a while I also checked the wires(resistance good but have 40,000 miles on them), replaced fuel filter, PCV valve, air filter, engine oil, Pwr Steering and Alternator belts.

After doing the above, the car ran like a dream! Power restored, nice smooth idle, just beautiful. Car ran great for a month straight. Then one day I drove the car home from work with no problems, changed clothes and 20 minutes later hopped in the car to go to dinner and now I have the acceleration problem. Came out of nowhere! I have been looking to see if maybe there was a vacuum hose or anything else that may have disconnected etc but couldn't find anything. My experience with car troubleshooting and repair is VERY Limited so if I am missing something really easy please go easy on me!

So, what do you think?
Thanks in advance for your help here.

Ron

 

[plymouthtalon]

I always start by replacing less expensive parts in succession until the problem is fixed. You might want to step up now to looking at the injectors, since you've done a bunch of low-end part replacements.

 

[boostnbuds]

Buying parts until the problem goes away is the dumbest thing i have ever heard. I have no idea what your problem is, but i wouldnt buy parts until it went away thats just crazy!

 

[TheGreenX]

I feel your pain man. I have the same exact problem. Feels like im driving my old Escort again . Sometime this week i should be taking her in so ill tell you what i find out.

 

[jce132]

Have you checked out the rest of your ignition systems? There are several sensors (namely air flow, throttle, crank and camshaft position) that dictate when your engine gets fuel and spark. Use a manual to check resistance/voltage values on these systems.

 

[flinguist]

Might want to check your coil pack too.

 

[plymouthtalon]

Originally posted by boostnbuds
Buying parts until the problem goes away is the dumbest thing i have ever heard. I have no idea what your problem is, but i wouldnt buy parts until it went away thats just crazy!

Uh... what do you do, take it to a shop and let them charge you labor rates while they check everything? If there's a problem my car's having and I don't know what's causing it, I replace the cheapest thing I think might be causing the problem. If that doesn't fix it, I replace something else that might be suspect. That may sound dumb to you, but ask some other people who have been on this site for more than a month and it may start to make sense. Noob.

 

[92awddsm]

If the problem is related to how much throttle pressure you give it, I would look towards the throttle position sensor. Test it and you will probably find the problem.

 

[ronhawaii]

Thanks everyone for the recommendations. I will be hitting my garage this weekend with your ideas in mind to see if I can make any head way! I will be sure to post the results here either way.
Ron

 

[ronhawaii]

Well, thanks to all who posted advice. Long story short, problem solved. Solution? Cleaned, treated for corrosion and reseated the plug wires at the coil pack. While troubleshooting the coil pack I noticed quite a bit of corrosion built up on the connectors. Cleaned them up and all is running perfectly now!

 

[plymouthtalon]

Good deal man. Always start cheap & simple like that and half the time you won't even have to replace anything.