I'm back working on this 1991 3.1L I've since replaced almost everything.

New Fuel Pump after finding out I had just replacd it with a TBI pump!
New Fuel Filter
New MAP sensor
New TPS
New Cap, Rotor, Plugs & Wires
New Igntion module

Here's the problem,, the car sat outside in the cold for like 1 month and I went outside and the car fired up like a new car and idled great. so I pull it into the garage to to look everything over and try to find the real problem which is why after it warms up it runs like CRAP!! it will bog out and almost die.

the 2nd problem is after I simply pull it in the garage and shut it off and restart it,, it will only run on "like 3 cylinders"..

I have verified that its a spark problem by hooking up a timing light to ech plug wire and more then a few are getting VERY spuratic signals.. like the#1 wire will only pulse every other time or maybe take a break and then come back. however I can move the timing light to he number 2 side and its firing 100% with no missing????

So I'm lie WTF!! can it be a bad cap and rotor?? a bad pickup on the ditributor?? or a bad coil??

Lastly is there a crank or cam sensor on this 3.1L?

I'm honestly at witts end with this car.
Brad M

 

I would suspect the crank sensor
Does the computer have any codes

I'm not sure if the timing light is reliable on the #2 cylinder, but very odd it would fire 100% correctly on #2 and not #1, perhapse #1 is grounding off somewhere if in '91 3.1's had still distributors and not coil packs which it what it sounds like on your post.

how would it be possible for any sensor to cause a problem that only occurs on SOME cylinders with a distributor system unless you've got the wrong rotor or cap or the plug or wire is grounding off

 

Also this car DOES NOT have a coil pack or crank or cam position sensor.
Check for codes pape clip between A and B

Check collant temp sensor would run like crap when warm dollars 12.00
Distributor Pick up coil 15.00 at auto zone
Coil 33.00

How many miles could be a timing chain.

 

I myself am strongly thinking its somewhere in the distributor..

the car only has 70K original miles,, and sat for 5 years in a garage and 5 years outside.

I figured since it was a distributor car it wouldnt have a crank sensor.

I'm gonna pull apart the distributor today and maybe replace everything once more.. I may have gotten a faulty ignition module?

Brad