302 help?

KillerStang · 11-04-2002, 12:53 AM

ok we are having problems with a 88 5.0, we put a e303 cam in it with new lifters pushrods and 1.6 roller tip lifters and we converted it to mass air. the problem we are having is that when we start it before it warms up it runs like **** you can hear it back fire through the intake. when we first started running it up and down the street it would fall on its face at 3k but now it hits 3k and studders and then it will slowly continue past 3k, but wont go over 4500 then the power just stops. durning no time does it actully have the power it should. we had a friend bring his scanner over and it read the egr wasnt working, speed sensor, thermactor system and other minor codes. we called tech support from pro-m. they said just worry about egr and speed sensor, we replaced egr and reseated speed sensor and make a couple conections in the wiring and grounds and stuff. the guy from tech support said to wire all the wires in the mass air conversion kit they first told me not to do. they were for the speed sensor and thermactor codes. they also had me re-adjust the tps and the idle bypass motor to adjust base idle. it should all be fine now, but we are gonna have our friend check it with his scanner again. tonight i just was running it with the hood open and could see the spark travel all the way from the distibutor to the spark plugs. i am replacing them tomorrow and well see what that changes. the thing is that even after fixing that stuff the car has not changed what it is doing and tech support isnt really helping much. I dont think they know what else to do and neither do we, we are kinda stuck right now. any help would be greatly appreciated.

NewAge 5.0 · 11-04-2002, 01:18 AM

is the mass air meter new? if not sounds like it is BAD or DIRTY the thin wire elements in there might be broke or dirty., try this first.. or maybe bad connection on it somewhere either the harness conections or something

jim_howard_pdx · 11-04-2002, 03:49 AM

Double check on the technique for your computer, but after checking the MAS wire, completely reset the computer. Then when the car fires, make sure NOTHING ELECTRICAL IS ON. No radio, no fan, no lights NOTHING. Then let the car idle for a minimum of 6 minutes.

The computer when reset, will work to re-establish a proper "new" idle with the new E cam. Nice choice of camshaft by the way!

You cannot use your pedal at all during this first 6 minutes. Let the computer do everything.

The way MAS works is that by using a fine filament wire, the computer monitors the temperature of the wire. As more air flows, the wire cools down, as less air flows the wire cools up. This is a very simple design. It works especially well for mid range torque and fuel efficiency. Actually, we typically see higher hp numbers from speed density type fuel injection set ups with sequential injection mode. On our race cars, we have the injector fire once when the combusion cycle begins, firing the fuel and air right at the hot intake valve. Then it fires again when the intake valve opens. This way the fuel charge is both homologous (evenly atomized) and dense (cool). It is fuel density, not fuel mixture that creates horsepower.

So much for MAS vs Speed Density......

I usually reset my computers by disconnecting the positive terminal of the battery, and turning the ignition ON. I leave it this way for a couple of hours, but I think only a few minutes are required.

Then I turn off the key, and reconnect the battery. Fire the car. Make sure NO POWER IS ON ANYWHERE. Just let the car set the idle and make sure you do not touch the gas pedal for at least 6 minutes. Then you should be good for a test drive. Check with the SVO group if you still have problems. They have tech bulletins out on just about every conceivable issue with their Motorsport Cams.

Always start with the simple and the rediculous first. I once had an engine with a totally clogged PCV hose. I did not find it until I removed it and blowed into one end. Then I found the plug in the middle at the restrictor.

Make sure your air/fuel sensor is properly torqued, and that the connection is good. The MAS or the sensor would be my guess right after resetting the computer.

Make sure you let us know your progress on this problem. Good hunting. Fun is right around the corner......or at least it should be.

88workcar · 11-04-2002, 06:45 AM

The last time I had this problem it was the dist. change the whole thing with a nother old one

Conman · 11-04-2002, 10:09 AM

Quote:

Originally posted by KillerStang
tonight i just was running it with the hood open and could see the spark travel all the way from the distibutor to the spark plugs. i am replacing them tomorrow and well see what that changes.

what do you mean you can see the spark?

you shouldn't see any sparks anywhere. I once had a set of Accel wires and the coil wire was arcing with the steel fuel line. Truck ran like **** and there was no computer anything to worry about. Never owned anything Accel ever since.

I would say that is your problem

jim_howard_pdx · 11-04-2002, 02:33 PM

If resetting the computer and checking all your wiring doesn't fix it, pull the distributor and have it replaced.

I too had a bad distributor once that allowed me to fire up and run to about 4k. It was rough, but it was running. Then anytime I tried to tip in the throttle it would go way rough, flatten, struggle andd even mimmick back firing. The rebuilt distributor fixed this for just 16 bucks.

Also, if you are running a roller cam, you must change the distributor gear to steel or bronze. The cast iron gear factory gear will get worn away by the steel cam gear and you will end up with scorched bearing and journals. You should make sure to ask for a distributor for a roller cam year mustang, that way you should get the right one. But double and triple check this detail. This is very important for all of you out there. Know what kills your car fast! This is one of those things.

Good luck and let me know what works to fix the problem.

KillerStang · 11-04-2002, 11:35 PM

ok update,
we swapped the dist. out of my mustang (90 gt) into his car that 88 lx, the car picked up some more power but it is still studdering and back fireing. we also swapped the mass air meter out of my car to his car to check if that was the problem but nothing changed. my bro changed the wires and nothing happened there, we werent expecting anything there he just changed them b/c they were shot. he also ran it through emmisions today and passed. right now my bro is out driving it. thanks for all the replies and the info, but anyone got any other ideas of what might be going on? thanks in advance

88workcar · 11-05-2002, 12:02 AM

What is the timing and the fuel set at. Put the timing at 14 and the fuel at 39psi. Is the cam strait up?

KillerStang · 11-05-2002, 12:39 AM

timing is at 10* and ill look around and see if i can find the paper we wrote all the feul stuff down on, i think it was like 41 WOT and 37 at idle, i dont remember and what do you mean by straight up?

jim_howard_pdx · 11-05-2002, 02:27 PM

Did you find out how to reset the computer, and perform this function. If not, the computer is trying to run the car off the old algorythem that was defined.

PLEASE RESET THE THING PROPERLY and let it set the idle. Then we can monkey with everything else.

11-04-2002, 12:53 AM	#1
KillerStang Registered Member Join Date: May 2002 Posts: 30	302 help? ok we are having problems with a 88 5.0, we put a e303 cam in it with new lifters pushrods and 1.6 roller tip lifters and we converted it to mass air. the problem we are having is that when we start it before it warms up it runs like **** you can hear it back fire through the intake. when we first started running it up and down the street it would fall on its face at 3k but now it hits 3k and studders and then it will slowly continue past 3k, but wont go over 4500 then the power just stops. durning no time does it actully have the power it should. we had a friend bring his scanner over and it read the egr wasnt working, speed sensor, thermactor system and other minor codes. we called tech support from pro-m. they said just worry about egr and speed sensor, we replaced egr and reseated speed sensor and make a couple conections in the wiring and grounds and stuff. the guy from tech support said to wire all the wires in the mass air conversion kit they first told me not to do. they were for the speed sensor and thermactor codes. they also had me re-adjust the tps and the idle bypass motor to adjust base idle. it should all be fine now, but we are gonna have our friend check it with his scanner again. tonight i just was running it with the hood open and could see the spark travel all the way from the distibutor to the spark plugs. i am replacing them tomorrow and well see what that changes. the thing is that even after fixing that stuff the car has not changed what it is doing and tech support isnt really helping much. I dont think they know what else to do and neither do we, we are kinda stuck right now. any help would be greatly appreciated.

11-04-2002, 01:18 AM	#2
NewAge 5.0 Registered Member Join Date: Mar 1999 Location: Sanford NC USA Posts: 155	is the mass air meter new? if not sounds like it is BAD or DIRTY the thin wire elements in there might be broke or dirty., try this first.. or maybe bad connection on it somewhere either the harness conections or something __________________ 88 Hatch 10.60's @ 130 89 Hatch Not as fast but holds its own

11-04-2002, 03:49 AM	#3
jim_howard_pdx Registered Member Join Date: Apr 2002 Location: Portland Oregon Posts: 247	Double check on the technique for your computer, but after checking the MAS wire, completely reset the computer. Then when the car fires, make sure NOTHING ELECTRICAL IS ON. No radio, no fan, no lights NOTHING. Then let the car idle for a minimum of 6 minutes. The computer when reset, will work to re-establish a proper "new" idle with the new E cam. Nice choice of camshaft by the way! You cannot use your pedal at all during this first 6 minutes. Let the computer do everything. The way MAS works is that by using a fine filament wire, the computer monitors the temperature of the wire. As more air flows, the wire cools down, as less air flows the wire cools up. This is a very simple design. It works especially well for mid range torque and fuel efficiency. Actually, we typically see higher hp numbers from speed density type fuel injection set ups with sequential injection mode. On our race cars, we have the injector fire once when the combusion cycle begins, firing the fuel and air right at the hot intake valve. Then it fires again when the intake valve opens. This way the fuel charge is both homologous (evenly atomized) and dense (cool). It is fuel density, not fuel mixture that creates horsepower. So much for MAS vs Speed Density...... I usually reset my computers by disconnecting the positive terminal of the battery, and turning the ignition ON. I leave it this way for a couple of hours, but I think only a few minutes are required. Then I turn off the key, and reconnect the battery. Fire the car. Make sure NO POWER IS ON ANYWHERE. Just let the car set the idle and make sure you do not touch the gas pedal for at least 6 minutes. Then you should be good for a test drive. Check with the SVO group if you still have problems. They have tech bulletins out on just about every conceivable issue with their Motorsport Cams. Always start with the simple and the rediculous first. I once had an engine with a totally clogged PCV hose. I did not find it until I removed it and blowed into one end. Then I found the plug in the middle at the restrictor. Make sure your air/fuel sensor is properly torqued, and that the connection is good. The MAS or the sensor would be my guess right after resetting the computer. Make sure you let us know your progress on this problem. Good hunting. Fun is right around the corner......or at least it should be. __________________ 1966 Customized for daily street and highway domination. 358 Windsor running 425 HP C-4 Auto and 3.25 Posi

11-04-2002, 06:45 AM	#4
88workcar Registered Member Join Date: Oct 1999 Location: Pierre Part, La. U.S.A. Posts: 1,850	The last time I had this problem it was the dist. change the whole thing with a nother old one __________________ 88workcar 1988 Mustang LX 342. 417rwhp @ 6800. 28 X 10 ET Drag, 4.30s, 10.69 @ 126.43 1.42 60ft. 11.13 @ 127.7 on BFGs 1.72 60ft Rice Hater # 42 To be old and wise, You must first be young and stupid I'm somewhere in tthe middle.

11-04-2002, 02:33 PM	#6
jim_howard_pdx Registered Member Join Date: Apr 2002 Location: Portland Oregon Posts: 247	If resetting the computer and checking all your wiring doesn't fix it, pull the distributor and have it replaced. I too had a bad distributor once that allowed me to fire up and run to about 4k. It was rough, but it was running. Then anytime I tried to tip in the throttle it would go way rough, flatten, struggle andd even mimmick back firing. The rebuilt distributor fixed this for just 16 bucks. Also, if you are running a roller cam, you must change the distributor gear to steel or bronze. The cast iron gear factory gear will get worn away by the steel cam gear and you will end up with scorched bearing and journals. You should make sure to ask for a distributor for a roller cam year mustang, that way you should get the right one. But double and triple check this detail. This is very important for all of you out there. Know what kills your car fast! This is one of those things. Good luck and let me know what works to fix the problem. __________________ 1966 Customized for daily street and highway domination. 358 Windsor running 425 HP C-4 Auto and 3.25 Posi

11-04-2002, 11:35 PM	#7
KillerStang Registered Member Join Date: May 2002 Posts: 30	ok update, we swapped the dist. out of my mustang (90 gt) into his car that 88 lx, the car picked up some more power but it is still studdering and back fireing. we also swapped the mass air meter out of my car to his car to check if that was the problem but nothing changed. my bro changed the wires and nothing happened there, we werent expecting anything there he just changed them b/c they were shot. he also ran it through emmisions today and passed. right now my bro is out driving it. thanks for all the replies and the info, but anyone got any other ideas of what might be going on? thanks in advance

11-05-2002, 12:02 AM	#8
88workcar Registered Member Join Date: Oct 1999 Location: Pierre Part, La. U.S.A. Posts: 1,850	What is the timing and the fuel set at. Put the timing at 14 and the fuel at 39psi. Is the cam strait up? __________________ 88workcar 1988 Mustang LX 342. 417rwhp @ 6800. 28 X 10 ET Drag, 4.30s, 10.69 @ 126.43 1.42 60ft. 11.13 @ 127.7 on BFGs 1.72 60ft Rice Hater # 42 To be old and wise, You must first be young and stupid I'm somewhere in tthe middle.

11-05-2002, 12:39 AM	#9
KillerStang Registered Member Join Date: May 2002 Posts: 30	timing is at 10* and ill look around and see if i can find the paper we wrote all the feul stuff down on, i think it was like 41 WOT and 37 at idle, i dont remember and what do you mean by straight up?

11-05-2002, 02:27 PM	#10
jim_howard_pdx Registered Member Join Date: Apr 2002 Location: Portland Oregon Posts: 247	Did you find out how to reset the computer, and perform this function. If not, the computer is trying to run the car off the old algorythem that was defined. PLEASE RESET THE THING PROPERLY and let it set the idle. Then we can monkey with everything else. __________________ 1966 Customized for daily street and highway domination. 358 Windsor running 425 HP C-4 Auto and 3.25 Posi