1987 delta 88 rough idle & no power under load

[intimidater]

i have a 1987 olds delta 88 royale with the 3.8 v6 and 63,000 miles, it started acting like it wasnt getting fuel so i replaced the fuel pump, strainer, fuel filter air filter, and sprayed a bunch of fuel injection cleaner into the throttle body opening, things got worse, now it idles really rough, but when u rev it up in park, it sounds good and revs fine, but under load it has no power and barely goes sometimes, pops n hisses... since then ive replaced the fuel regulator, idle air control valve, & spark plugs. The fuel injectors are all ticking and tested good with ohm meter, the timing chain and cam sensor were replaced 6 months ago... every now n then i get code 32 EGR valve, but i can puch up on the diaphram with my finger and it seems to work ok, yesterday i got code 34 air temp sensor, for the first time. Any ideas im going nuts trying to figure this out, i also ran seafoam thru the vac line twice now and it seems to help at first but fades away. could it be the ignition control module or coil? it also has the correct fuel pressure 45psi.... HELP PLEASE!!!

[Tech II]

Check coil output with a spark tester?

Does this have 3 coils or one coil with 6 terminals?

Plugs were replaced...what about wires?

Exhaust back pressure high?

[intimidater]

its got the older style coil...has one piece w/ 3 wires on each side! the exhast is rusting out, kinda loud with a hole or 2 in muffler. how do u measure exhaust pressure? all i did with testing coil is with a test light making sure each wire was firing. i didn't change the plug wires yet Cuz the look like they're in descent shape.....

[maxwedge]

Tough to tell what the symptoms are here, is this a dead miss at idle or under load? The egr not closing fully can cause stumbles, poor idle and hesitiation but at 40 mph it would run ok.

[intimidater]

at 40 it runs ok but at 55 it will barely go any faster, almost impossible to go 65

[intimidater]

it misses at idle and under load, just not while revving in neutral!

[Tech II]

Way back when, when dinosaurs roamed the earth, there was a campaign for 86-87 3.8's.....

Quite involved and luckily, replacement parts were covered then under the campaign.....such as MAF, coils, etc.

You have the infamous Magnavox coil, which was prone to failure.....can do two things...check the output of each terminal with a spark tester(best thing to do), or ohm out each pair of secondary terminals(which may or may not show a problem).....I believe secondary resistance for these was 10K-12K ohms....if one or more pairs is out of spec, need coil....however, can be in spec and still fail, that's why the spark tester is your best bet......

Wires can't be checked just by looking at them.....not that expensive....

I doubt it's injectors, because it would do it every time.....

As for exhaust, an exhaust leak near the O2 sensor(like the seal at the ex manifold/exhaust pipe), could skew the data from the sensor(causing the car to run rich thinking it's a lean condition) and could even foul the O2 sensor....was vehicle scanned for codes? Don't need a code reader, can read flashes of CE light by jumping "A" to "B" in the ALDL connector, key on, engine NOT running......will flash "12" 3X's, and then flash any other codes 3X's in succession....when it flashes "12" again, all the codes have been read....bad O2 sensor could set a 13, 44, or 45 code.....however, those codes could also be set by other things such as a vac leak, leaking injector, dirty air filter, etc.

Could have a back pressure problem.....can test that by removing the O2 sensor, and attaching a pressure tester(need special fitting)....or you can create a leak at the exhaust manifold by loosening the bolts and creating a space(could create problems though, on this year car, if nut/stud threads are rusted bad) or by removing the O2 sensor and just briefly driving the vehicle....if you now have power where before there was none, then you could have a bad cat(most likely) or a blockage in another part of the exhaust(rare).....

[intimidater]

I checked coil with ohm meter and 2 posts had no resistance, bought a new coil and problem solved, runs like new!!! Thanks for all the help!