Insane Hesitation
 

I am a little stumped on this one. I was thinking something with fuel but i am sort of leading away from that but still could be a good possiability. Well anyways It starts and idles fine. compression is fine. It will drive fine if i am very very slow in gaining speeds.
But if I try to press the gas much at all it really hesitates at just about any rpm. seems to be a bit less at higher rpms but its a bitch to get past 4k rpms. But heres the funny thing. It dosnt do it all the time. It seems to do it when the car fully warms up. I just took it for a test drive to test some things out and it didnt do it at all untill about 5 miles down the road. So makes me believe something starts going wrong after its fully warm. (maybe o2 sensor?) My dad tossed in the idea that maybe a spart plug coil is breaking down or something when it gets warm??? just a suggestion. I am going to let the car cool down and try to get a video of it and show the rpms and speed and let you listen to it. It really backfires bogs down like crazy when i accel.
After looking at the SAFC it seems like it is fine untill the throttle says 100% and if i try to push the gas anymore is when it really happens badly.
Could something with the throttle body be messed up? We were looking at it and it looks like alot of things are out of sinc on it. We cant even set the tps because the screw will come out of the threads before we can even get it to 1. it is at about 1.50 right now. Any suggestions would be great.

I checked the injector plug wires and they are are getting correct readings. I changed out the primary injectors and it didnt help at all.

If this dosnt really make sense just let me know, i asked alot at once so this might be confusing.

well after a bit more of messing around, it seems like its not running on the back rotor ( maybe not getting gas) but only after its fully warmed up. I was able to still reach 10lbs of boost well it was semi-warm and it drove awesome, but after it fully warmed up it all started again. We took off the back spark plugs well it was idling and it didnt notice a difference really. making us believe its not getting gas when its fully warm. but it still has spark.

Before you started talking injectors, it sounded like a clogged cat or pump inlet fuel filter...

If you still have the stock injectors on the car, you can swap a secondary into the primary spot that you think is bad and see if that helps...

Well I have a straight pipe. so it wouldnt be clogged. I have 660cc injectors in the secondary. But i did swap the old secondarys into the primarys and it still didnt do anything. I havnt really checked out my fuel....I was thinking of checking it out and rewiring it maybe. maybe im loosing pressure for some reason and not getting enough gas. I have a walboro255hpl or something in it right now.

also its a 87 TII btw.

has anyone had any problems simular to this after changing out the pulsation dampener with the bango bolt? I started doing this soon after i did that. But it is probably just a conciedence. (soon as in a week or so)

Think im going to change spark plugs tomorrow and check the timing and go from there.

check the fuel pump.

otherwise im kind of getting stumped here.

also my boost tends to be around 10-13....should i change the timing at all? or just put it where its suppose to be stock.

any other suggestions would be great

^

These are classic worn out TPS symptoms.
-The golden test:
Unplug the TPS connector.
Clip a cheap analog (needle type) VOM on the orange & black pins.
Set it to the 1K scale.
Hold off the throttle & work the TPS plunger in & out.
You should see a smooth sweep from ~0 to ~5K ohms.
Any bad spots or drop outs in the stroke - it's bad & will give fuel cuts at part throttle.
-And- It usually gets worse when it's hot.

The ECU sees a bad spot as "idle" and if you're trying to do anything over 1500 RPM it freaks.

I will have to look into that then tonight. maybe thats why i havnt been able to keep a good idle yet.

do u have a stock BOV or is aftermarket. cuz i had the same problem since i had the car. and last night i tightened my after market bov to stiff, and it seemed to work fine now. good luck

hum....Really??? I have an greddy type s that is not tight at all as a matter of fact is only on there finger tight. Maybe that is causing my hesitation problems???

well i still have my stock bov. But I guess I will just have to start checking components and such and go from there

My first bet is still a bad spot in the TPS stroke.

You know if the TPS is interchangable between n/a and tii?

I will take try and test it tonight. My multimeter uses a clip on end thoough not the needle type, i am not at my car to look at it but could i still use that?

So I should check the volts of it? or should i do the normal with resistence?
When you mean hold off the throttle and work the tps plunger in & out, do you mean the screw? or push that throttle piece that it sits on?

i still need to try testing my tps. it was set by sonicrat when it idled like shit at 1200rpms and now i have it at 500 rpms. so i guess i should try setting it again. i think thats my problem. everything else seems fine. im guessing that its ur problem 2 huse

Well I believe most of the settings on my throttle body are completly out of wack for sure.

But me and my dad checked the timing which was off alot actually, and we set it back to where its suppose to be. We couldnt find the yellow line though so we just set it with the T1 on the red line and it def helped out alot. I am going to try and clean it a bit to see if we can find the yellow line so we can set it correctly.

But now my idle is all the way up to about 1300 and closer to 2k when its hot. (hot as in driving for 15mins).

What causes the Ecu to retard the timing? The first test drive after changing it went well, but right as i was pulling into the garage the idle dropped to aroud 700 and the timing was completly different from when we set it. But we reset it and such and it hasnt done it yet.

so i guess i am just going try and get that TB all set back to stock positions and such by following the fsm and haynes. and then readjust the tps and cables and timing and see what happens from there.

Hey check the vac line that comes in from the charcoal can. If it's off you'll have just the problems you origionally described.

I dont get why that would cause this kind of problems? Isnt that just to vent air or something simular to that? I removed that though. One line goes to the gastank i believe and the other just went to the side of the engine bay and towards the ground.