power cut almost completely under engine load

[stang-geoff]

I've about lost it with this car. It's getting frustrating to say the least.

Anyways, I'm having some serious driveability problems. My car is having misfire problems and under engine load the power is completely gone. It's like it hits a brickwall and the car will not accelerate. Such as if I go half throttle to WOT at around 2-3000rpms+ this problem will occur. It seems this problem is sensitive to heat. As this problem is intermittent. On a cold start this problem sometimes wont exist for a good 10-15 minutes and the problem will gradually get worse and an hour plus of continuous driving the car will become more difficult to drive for simple commuting

I haven't had this car for to long but it has always had this issue. I did basic tune up stuff such as replace the fuel filter and the cap and rotor. It had no effect. The car also came with new plugs properly gapped at what I believe was .040-.045". I finally got a timing light and found my timing was off by 5-10 degrees. Adjusting it still hasn't improved my situation. today I just pulled my tfi module on the distributor. Brought it in to the auto store and it failed the bench test. I installed a new module and the car still drives the same. I also used a tester on my plug wires to see what voltage my coil is firing at. It seems to be operating between 30-35 kvolts. I've pulled plug wires one at a time to see how it would affect the engine output and it seems my entire left bank is running weak. My exhaust is rotting out and it seems there's little to no exhaust flow on the left tailpipe. I don't think there are any exhaust leaks before the cats though.

Tomorrow I'm going to run compression tests and see if I can borrow a fuel pressure gauge and see what my fuel pressure is when I recreate my symptoms.

Does anyone have any ideas where I should go from here as far as diagnosis? this thing is kicking my ass majorly.

At this moment I'm thinking I might have a bad o2 on one bank or a clogged cat since I'm getting no flow on the tailpipe but most of the exhaust gases could be exiting some place else on that bank.

 

[Jmunk]

Test the coil and check that all your ground wires are good.

 

[stang-geoff]

I already tested what volts it was operating at. Do you mean going with an ohm meter and check resistance?

 

[Makdaddymac]

wish i had answers but there are three of us with this same exact issue with three seperate threads, i will in inform if i find anything out, i was going to try the tfi module and still will but now im not as hopeful after reading your post...good luck and please let me know what you find out

 

[SMOKEDYA]

I'm thinking it could be the cats. Get it warmed up and get a heat gun, check the temp BEFORE the cat and AFTER the cat on the exhust. If the temp is way way diffent then your cats are most likly clogged!peace











john

 

[stang-geoff]

Well today I got a hold of a fuel pressure gauge. I ran the car to wot on some open roads and I was able to get it to act up. My fuel pressure when I was recreating my symptom went as low as 12 psi.

My fuel pressure was at 32 psi under cruising conditions and would go up as high as 40 psi under a load before the symptom occurs

I was also thinking of testing my cats with the laser thermometer but shop got locked up before I got a chance to borrow one.

So it seems like I have a fuel problem with my wot issue. On monday I'm going to see if I can borrow a vacuum pump and play around with the regulator. I'm leaning towards a new fuel pump though.

If I can get a chance I would like to test the cats with a thermometer sometime. I'm due for emissions so I need to get this car in good running order.

I also wish I had a scope to look at the duty cycle of my injectors. It would be interesting to see what the injectors are doing when this problem happens. Have at least one channel looking at an injector on each bank to see if there's a difference between them.

Also, I'm finally feeling relieved. I feel like I'm getting somewhere with this