Ok I take my car for a drive today and i noticed the car was backfiring way more than normal while i was decelling in gear 3300 rpm or so and less so I tried disconnecting my tps to see if that fixed the problem and it didnt fix anything. I then hooked it back up and tested it out again, and still have the problem with backfiring on decel alot , way too much like constant .

Then I floor it and now im getting the 3800 rpm hesitation as well and its very very noticable, almost like the car suddenly hits a wall and stop revving.

So I then proceed to check out the cars grounds and tighten all the grounds I see in the engine bay, the one on the top of the block was actually loose and I tightened it up a bit but the car still has the hesitation just maybe not as bad or not happening as often but it definitely still does it pretty much almost everytime you try to floor it through 3800 rpm range.

I also after that tightened up the bolts on the terminals for the battery so the wires would be held in tighter. This did nothing either and I also tightened the ground on the side of the strut tower this didnt help either.

The funny thing is my car had this problem with the 3800 rpm hesitation before and it went away on its own somehow, now 3000 miles later its back, but i dont think it was having the problem with lots of backfiring on decel though....but at one point it was so bad the car would not rev past 1500rpm, that stopped also.

Anyone have any ideas what is causing this ? I really dont think the tps could be causing this because the problem went away on its own before, the only ground I'd be left to check is the ground on the starter and see if i messed something up on that, because strangely the starter has given me problems before that have fixed themself.

I also saw somethign that was a black box that was dangling that was disconnected thats near the oil filter/clutch slave , but i was told this isnt a ground and only a oil pressure condensor (dont know what its used for tho).

Anyone that could help it would be much appreciated , I dont have any ohmeter or anything like that so if anyone is going to say to use one I dont have one

Maybe I'll get lucky and the problem will go away by itself again, but Id like for it to go away for good. Oh and does this 3800 rpm hesitation have any chance of messing up your engine from doing it ? It feels like a fuel cut basically but not sure whats actually being cut or whats actually happening when this hesitation is happening.

Seems like this mod would probably be a good idea to do from Aaron Cakes site -

5. Additional Grounds
I know at the beginning of the article I ranted about adding unnecessary grounds. As it turns out, there is one location where an additional ground can be very beneficial. If you are experiencing the notorious 3800 RPM hesitation, adding an additional ground to your boost/pressure sensor is a known cure that seems to be effective most of the time. Remove and clean the boost/pressure sensor plug as described above. Thoroughly clean both the sensor and harness contacts with contact cleaner. Locate the ground wire (this is the brown/black wire on '86-'88 cars, and the black wire on '89-'92 cars) and separate it slightly from the harness. Cut it, then strip both ends a little. When you cut make sure to leave ample room on both ends. Slip some adhesive lined heat-shrink tubing over one end before twisting both ends back together with an additional third wire. Solder the connection, cover with dielectric grease and then use the heatshrink tubing to seal it. Now run this third wire along the harness to either a good body ground or (preferably) the ECU ground on top of the engine. This essentially regrounds all the engine sensors except the O2 and knock sensor.

 

You can find a ton of threads on the 3800 hesitation. What worked for me was to simply clean the ground under in Upper Intake Manifold. Just cleaned it with some sandpaper and cleaned the surface it's attached to.

 

Cool thanks, what about a wire brush ? Or would sandpaper be better ? I think sandpaper probably would be better just wondering.

 

Adjusting your TPS will solve a lot of problems. probably your backfiring and hesitation is because of that. also, i suspect you have clogged catalytic converters.

 

Well the problem went away before (3800 rpm hesitation) and I never adjusted the tps, but back then it didnt backfire on decel like it is now. (is it possible that my grounds are messing up the tps also , or possible that my tps went bad)

Also I have a straight pipe in place of the main cat that was there, aside from that its just all piping ( header/catback)

 

My hesitation comes and goes. I don't take my car that high often (at least at full throttle) so I have yet to fix it.

It keeps your oil pressure gauge from exploding (semi-humor... <3 to Hailers).

FAQ's... "What is this little black box with a single wire and a small metal tab that is mounted near or on the clutch slave cylinder?
It is the Condensor (capacitor) for the Oil Pressure Sender. It is needed to protect the oil pressure gauge from burning out in the event of sender failure, and for smoothing any erratic pluses from the sender."

I hate to be the *** that says it but... go buy a multi-meter. I bought an analog (whatever the needle ones are called) one for about $10. My digital one was like $25. You need one if you are going to work on your car.

I've never heard of it messing up an engine. As far as I understand it, the secondary injectors fail to fire (or fire erratically) which causes the engine to stumble (not enough gas obviously).

You can sandpaper them but buying a ring terminal is very inexpensive. When I get around to it I'm just going to buy new ones. It'll be good crimping practice anyways.

 

Ok i cleaned all the grounds and went for a drive and the hesitation didnt go away nor did the backfiring on decel and when downshifting.

So I then swapped another tps I have onto the car and now the hesitation has gone away but the car still backfires constantly when i downshift or when Im deceling. I messed with the tps setting and that did nothing for me. I also cleaned all the electronic connectors with some electronic cleaner spary too which seems to help nothing.

Could it be that both these tps are bad and this one is just not as bad as the other one ? What else could be the cause of my problem ? Everything on this car has less 3000 miles or less, so dont say its my engine is bad, the spark plugs, fuel filter, fuel injectors. Because theyve all been previously maintained/replaced, fuel injectors cleaned engine rebuilt etc.

I might just try finding another tps but i dont have the money for one , I would test my tps but i dont even have the money for an ohmeter.


Edit - Also , this backfiring on the decel (it does it quite a bit) , this isnt bad for the motor right ? i was assuming its not since its only doing it when im not hitting the gas but I was racing a car today so now im paranoid and just want to know for sure. (car is running great right now aside from the stupid backfiring)