please help January 02, 2005, 11:16:23 PM just fired up my new enguine today and results are dismal. my setup is stock 99 explorer engine with 80k but slipped in a crower 1511 and some 1.7 cobra RRs. Im using 88 GT harness and computer but spliced on the expo injector connectors. I eliminated the egr spacer and all that applies. I used the resister voltage divider to tell the computer the egr is closed. It starts and idles but if I open the throttle at all it bogs and backfires. All this is in an 88 Tbird. I know every vacume line is connected. I know im not 180 out because I was and it would not start. Fixed that and it fired right up and will idle but thats about it. It seems to be hitting on all 8. In addition I have a lot of clatter from the valvetrain. I had a lot of lash after putting in the cam but assumed the lifters were not pumped up. Does the crower have a smaller base circle than the the stock cam? Plan to call them tomarrow and ask about that. I have changed a lot from stock 88 tbird but basically its the same as a 93 cobra exept the cam and p heads vice gt40's. Any ideas out there. I have not put a timing light on yet but I doubt Im a tooth off and I should be able to get it close enough to run decent. I will do that tomarrow first though. Quote Selected
Re: please help Reply #1 – January 03, 2005, 04:35:35 AM Ok frist off i could not find a crower cam with that part number.The chatter from the valvetrain not normal. Sounds like u need to tighten the rockers still. Is this a hyd roller cam? Will this cam work with the computer? whats the lift and spring presure? Quote Selected
Re: please help Reply #2 – January 03, 2005, 08:11:21 AM Cam is probably part # 15511. If this is indeed the cam it should work very well with a Mustang computer. A lot of guys woith speed density Mustangs swear by it and say it has great idle characteristics. As far as the base circle size on the Crower I couln't tell ya. I agree with SirChirpALot in that it does sound like some tightening is in order. Did you happen to check to see if you needed shims for the rocker arms? Quote Selected
Re: please help Reply #3 – January 03, 2005, 10:15:48 AM also, what computer are you running? Quote Selected
Re: please help Reply #4 – January 03, 2005, 11:01:09 AM It is the 15511 and is a Hyd roller. I used ford cobra (crain) 1.7 rockers. They are bolted down tight just as you would do the stockers. I did not have the lash with the stock expo cam and the same rockers. I pulled the rockers and lifters etc to put in the crower and now have lash when the valves are closed. I hoped it was just bled down lifters but evidently not as I ran it long enough to pump up. I dont know what shims would be for unless it is to lift the rocker off the pedestals to add clearance. I did have to shorten the bolts as they were bottoming in the hole before the rockers were bolted down tight. It's not loud like its gonnna break something but like a toyota 22r that needs an adjustment. I know these are zero lash engines so there should be no ticking at all. I suppose I will be installing longer pushrods before the car sees the road but still want to get it to run rightthe computer is an 88 must gt SD manual computer (DA1) I have a spare I can try. I woke up this morning and on my mind is the orange ground wire at the back of the harness. It is a shared return for the TPS and EGR and maybe something else. I think I need to check that as I dont remember connecting it. Also I have a spare TPS I can try. I would wrather check sensors with a DVM instead of easter eggn' and running the engine more than I need to but could not find anything in the tech section on it. I know the TPS should be at or close to 5vdc at WOT but I dont know the ohm values for static testing it.One other item I could use help on is the MAP. The cool cats H.O swap thread says I have to change to a H.O. Map. I went to Auto Zone to get one and checked the Part no. for an 88 tbird 5.0. against an 88 GT and they are the same part no. I could not try this at ford as they were closed. At 47.99 I thought I would try the stocker. Quote Selected
Re: please help Reply #5 – January 03, 2005, 08:11:02 PM The TPS sensor should sweep from approx 0-4500 ohms. You can check voltage with the engine off, the 5v circuit that feeds it is regulated by the EEC so its just as accurate engine running or not. Should be .6-.9v closed throttle to approx 4.5v at WOT.As far as the MAP sensors, Ford may have different part #s for them, but I've never seen any difference. I've even run 4cyl MAPs on a 5.0 with no problem. In the Probst EEC-IV book, he describes it's operation and has a table for the frequencys at different vaccum points. No where does he mention the readings will vary with different engine applications. Quote Selected
Re: please help Reply #6 – January 03, 2005, 09:29:28 PM Thanks TC 5.0, It was the orange ground wire. I hooked it up and now it runs almost normal. I still have the lash prob but thats a seperate issue. What I have now after setting the timing to 10 BTC (with spout removed) is it wants to idle at 2700 rpm. I pull the IAC or idle bypass conector off and it idles normal but will hunt a little. In park you can hit the gas and it gains rpm like a two stroke race bike but when driving it does not like mild application of throttle. Hit it hard and it will run, much harder than the stock SO but there are still some issues to deal with. I used the stock expo 65mm TB and IAC, just spliced the expo connector on to the GT harness for the IAC. Do I need to put a mustang IAC on the TB? Also I used the expo oil pressure and water temp senders and my oil pressure is pegging the guage and my water temp does not work. Both were single wire like stock bird/stang but had different connectors so I spliced the expo connectors to the stang harness. The stock bird oil pressure sender had an inline resistor so I will try putting that back and see if that cures it. I will swap back to the stock coolant temp sender also. I did use the stock enguine coolant temp (the one the computer monitors) so that should not be throwing off the ECU. If anyone has any ideas to my idle issues please advice. Thanks all Quote Selected
Re: please help Reply #7 – January 03, 2005, 09:33:38 PM Just thought of somthing. When setting the timing with the spout pulled out it will idle fine with the IAC hooked up. But when the spout connector is in it idles way high 2700-2800 rpm. What gives? Quote Selected
Re: please help Reply #8 – January 03, 2005, 11:15:19 PM your cutting off the engine before you hook the sprout back up right?be careful hooking the sprout back up with the engine running.,, why did i say that?its not like you could be careful of anything cause you cant,, its gonna break something with our without your care. Quote Selected
Re: please help Reply #9 – January 04, 2005, 04:16:49 AM Too much TPS voltage will cause high idle, make sure it is less than 1v. Quote Selected
Re: please help Reply #10 – January 04, 2005, 08:50:22 PM the tps was at 1.6 vdc. the t bird tps does not fit the explorer 65mm TB right so thats as low as I can get it with the screw holes lined up. I am going to splice in the explorer TPS and see if it works ok, it fits the TB. Also with key on engine off there is 12.5vdc to the IAC. Is this correct? I could not check it with engine running as I am waiting on pushrods and shims to get my valve geometry sqared away. thanks, Jay Quote Selected
Re: please help Reply #11 – January 04, 2005, 10:05:45 PM QuoteAlso with key on engine off there is 12.5vdc to the IAC. Is this correct? Yup, it gets 12v from the same feed as the fuel injectors. Quote Selected
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