Help 91 vert wont accelerate
 

Hi Thanks for your help! I just bought a 91 vert day before yesterday it ran perfectly fine the day i got it and yesterday but to day oddly after i washed my car it started acting up. If i press the gas pedal more then 1/4 way in it bogs out and wont rev. I took it to autozone and spent like 6 hours there today :/. We did a compression test on both rotors it had 91 in the front and 88 in the back we even did the poor man test and i got between 3 and 4 psht when cranking over on both rotors. I pretty sure my seals are good. There are no codes. We check and tried different spark plugs the guy was nice enough to let me use brand new spark plugs and it still bogged down. So we put the old ones back. We check the TPS it had good voltage. Oddly enough it revs fin from the throttle body. It only bogs down when I am driving?!!? Please help im at wits end! ive been looking through the threads and i cant seem to find an answer.

oh one more thing!! i just thought about this. yesterday morning i did run fuel system cleaner through the fuel. I am wondering if it could of ruined my 02 sensor would that cause the bog as well?

Most likely if you washed the car and now it won't run right.It would point to the Electricals being hit by water.
Water in connectors, Kirk..Not good to do.
Try to get a way to dry the connections.
A Hair dryer is usually good.
Take the spark plug wires off too and Blow hot air at the plugs,wires,coil.
See the CAS( crank angle sensor..or "distributor" in piston talk) .
take the 2 Philips screws off that,remove the circular lid and Blow hot air in there too.
Get the air at the Fuel INJECTOR connectors too.If you hit those with water then you would get intermittent fuel.

Well, if it ran fine when you got it and now it runs terrible after adding fuel system cleaner, ive got money on the catalytic converter being plugged up. You'd be surprised the amount of carbon built up in a ~20yo car, now coming out sticking to your cat.

Do you have emissions in your county? Might be time to unbolt the exhaust and take a peak at the cat. And if it was me, id just go ahead and knock that sucker out while your in there :icon_tup:

A clogged cat is notorious for accel issues. The motor is being choked. By no means am I with the car identifying other causes, but thats my .02 from what youve said.

Oh and 91 and 88 psi for comp test is not good. 89 or below needs a rebuild

Rebuild?.No.Don't count the engine out yet!
It's Ok for now.It will run fine on 80-90 per rotor.
I've seen 70 psi TII engine Run.Good...and they would scare the crap out of you.
Start back-tracking what you did before it ran crappy.Your answer is there.

Encountered and solved this problem recently for a friend... Check the main ground that goes underneath the upper intake. Also if you have a volt meter, check all the grounds leading to the ecu and if that does not help, try a another adjusted tps.

The haynes manual was saying compression should be above 85? Ok so all my wires n plugs are dry. I didnt spray the engine bay down or anything and i hand washed it. OK i just found another thing wrong wondering if it could cause the problem. My radiators coolant sensor is leaking it seems like. No low coolant light though :/. Problem is still here. Ok this is getting weirder... My exhaust has no smoke or anything coming out of it but sparks and flames are coming out the exhaust now when it bogs ??? so maybe it is the cat? Or is that an injector issue?

OK so here is an update still not running right sigh :( replaced spark plugs and wires found that the o2 sensor was dead so replaced that too> I am going crazy. However the new plugs and wires seemed to of helped the idle and start up but the limp mode or what ever it is seems to still be in effect. Next suggestions please

Try running the car w/the Oxygen Sensor removed. If it runs better then you likely have a clogged cat as previously suggested.

alright im almost positive i found my answer the back 5 or 6 port what ever one it is wont move with pressure applied like the front one so tomorrow morning off comes the intake manifold

The 6 the port not opening will not cause a severe issue as you describe. Sounds like limp mode to me. How did you check codes? Maybe bulb is blown.

Hello now i have a new problem.... sigh :( well the ports got cleaned up and work now and the car idled and ran fine. Let it idle for about 5 min after driving it of a bit to let it warm up fully. I turned it off went inside to get ready to go out to celebrate the revival went outside and it wouldnt start. That was about 1 1/2 ago!! lmfao!!I took it to the mazda shop they ran the codes all it was throwing was hard starts. They told me my wires were shorting out so I order new ones. I got it to start once today and it died about 10 seconds after. Tried the deflooding egi fuse out crank 5-10 sec about 4 times. That did not help so i did the spark plug removal. I cleaned each spark plug. I put another new set of wires on today. It seemed like it helped the car felt like it was having less trouble starting. I ordered a new set of NGK plugs as well. The guy at the shop told me that in the winter when its colder you should run 6 -8 plug rather then 7 - 9 if you want to have your car to start in under 50 degree weather. I am not sure if this is true so i ordered a set of eather and they are the laser platinum plugs they should be here on monday or maybe even wed after xmas but hopefully on monday. I have a sneaking feeling my fuel pump is acting up because one of the deflood attempts it took alot longer before it seemed to have enough fuel to start but it seems like its just an inch away from starting. Any suggestions? btw the cat and exhaust are fine. compression is also fine the mechanic told me. He also told me it took them forever to get it started just to find out the wires were bad. He also said hard starts where the only codes. I did take off the fuel pump acces panel and check the wiring and it was all good but i noticed it was still the factory fuel pump. Im going to order a new one of those new payday already did the fuel filter. If i dont have it running but the payday after that im going to het a new oil metering pump. Then a new tps because that thing is un godly expensive compared to the other 2

im still leaning toward fuel delivery. a bad tps adjustment could cause issues. mass airflow sensor could also cause these kinds of issues.

ok so i made a video sry its upside down but here is the link

im actually having a very similar problem right now with my 86 FD. still working on it as well but a lot of this has been helpful