1986 TPI engine boggin after 3500 rpm have no idea what could be the problem any ideas would greatly help .
thanks in advance. WOT also is a problem just a bog. Could it have someting to do with fuel pressure. It almost seems as there is not enough fuel being delivered to the system. Advanced the timming with the distributer helps slightly. Even with slow accleration breakes down at 3500 4000 rpm.Might be pick up coil
dont know help please. Could it be the coil?

 

Dick,

You are correct on both guesses. Either fuel pressure or a weak ignition could cause your symptoms. Your addition that the engine bogs at WOT regardless of RPM would lead me to suggest the fuel pressure first. Ignition miss can occur under WOT since the cylinder pressure can be high enough to quench a spark from a weak system, but I'm guessing fuel delivery.

Check the pressure at idle with the vacuum hose still connected to the FPR. The rail pressure should be 37 PSIG +/- 3 PSIG. If you are much below 34 pounds, you can experience lean mixtures. Of course, teh first thing to do would be to check or replace the fuel filter. Sediment in teh tank can clog even a new filter if you ran the tank too low or got a bad load of fuel.

If the filter is new, test the FPR by pinching the fuel return hose. The pressure should climb. If not, the pump may be weak. If the pressure climbs with the fuel return line pinched shut but won't maintain otherwise, the FPR is suspect. If you get that far and have ever wanted to have an adjustable FPR, now's your chance.

If the fuel pressure checks out, start scrutinizing the ignition. Don't overlook the reluctor and pickup, HEI amplifier/switching module, and the coil itself. If your '86 is like mine, you still have the coil-in-cap distributor. There is nothing wromg with them, but they are a little more sensitive to contamination and moisture. Make sure the car and rotor are clean as well.

 

I've checked the fuel pressure around 38psi at idle.
checked the pickup tested ok
checked the coil again tested ok
The engine runs great to a point i mean to start and accel
slowly to about 3500 rpm in drive. if u punch it feels as if itloads up and then dies let off the gas picks up again. Anything past a quarter peddle an it just boggs when in drive. Im going to check the fuel pressure again to make certain that it is not the problem.
Thanks for your time if you can think of anything more please let me know. I will post you about the fuel pressure and the fpr.

 

hit the cat with a rubber mallet and listen for rattles even if you think your exhaust is flowing good .
tap the MAF with a screwdriver when idleing. it it cuts out or dies, replace it.
take your ing. module to autozone and have them test it.
check your spark to make sure it's a nice blue color.
check the fuel stuff like vader suggests.

Jess

 

I will try the cat tomorrow but it seem ok i have tapped it and no
noise but did notice the car performs a little better. May be a
fluke. When i noticed the performance increase i took it for a spin
At a stop sign i punch it and it backfired the code 43 (knock sensor) came and performance dropped considerably, i stopped put in park then it corrected itself and light went out. This is the first time this has happened. I still think you may be right with the cat. So i will try it and let you know.