toad636

Can someome please help me out? I just picked up a bone stock original 88 L98 from the original owner and I have a couple issues. First, my air box cover has an IATS in it but it is not plugged in to a harness. I cannot find the harness anywhere under the hood. Is this supposed to be here or do I have a donor airbox cover? Will this cause problems? Second I have this annoying problem of the check engine light coming on after I shut the car off and then restart it. Sometimes when I start the car it runs normally no light and I can drive it forever it runs great. Then I shut it off to get gas or food, go back start it up, sometimes no light and good. Sometimes the light pops on and the car idles 300-500 rpm in drive and surges between 500-1500 rpm in park, and the exhaust stinks like hell burns your eyes and the car runs like junk. I took it to a local shop and they told me it threw a mass air code up. I didnt trust them and my dad owns an 87 formula 350, so I pilfered his Mass air for a couple days and gave him mine. Both cars run as they did before the swap. If anyone has any ideas I would be grateful as I dont know squat. I'm not afraid to spend the money to fix it. I just dont wanna swap sixty parts to get there or hack it in. The car is cherry stock and I intend to keep it that way.

red rock

iTrader: (2)

Next time the ses light comes on, check the code yourself so you know for sure. A MAF code can be cause from a few things besides a MAF sensor. A burn off relay or MAF relay, vacuum leaks etc. As for the IAT, It is mounted under the back of the plenum, but some move it out to the air box cover. Yours should be plugged in under the plenum or the wire harness extended out to the air box sensor. Oh and by the way, welcome to TGO.

toad636

Thanks Red Rock, I took your advise. I took the car to a local performance shop my friend recommended. They actually showed me the Snap on scanning tool screen and emailed me the info that it was reading. It does say the only code is maf. They also shook it down visually for vacumm leaks. They recommend I throw a Maf in it. Also I saw what I think is the IATS at the back of the plenum threaded right into the bottom of the plenum. Thats weird to me for it to also have one installed in the air box cover. It actually has a threaded bung that looks factory that its screwed into. Is there any advantages one way or another for the different locations? I dont think it is giving me any problems due to the fact MAF was the only code.

red rock

iTrader: (2)

By moving the IAT out to the air box, the sensor reads cooler air resulting in a little better performance. The theory is that the plenum gets heat soaked from the engine resulting in a little sluggish performance. It's the same as when you first take off with the car when it's cool, It feels a little snappy than when it get's warmer. As far as a MAF is concered, you did a swap with your pop on the MAF with no difference you said. So rather than spending upwards of $150, I would look at the relays first. The burn off RELAY and the MAF sensor RELAY are cheap to change first. There are a lot of threads on here about MAF problems, so read up on them. Good luck

toad636

Ok so here is the latest. I took to a reputable shop and of course maf code came up. I bought a brand new maf sensor. Ran great for two days. Then did the same crap. Bought 2 new relays, 1 burn off and 1 mass air relay. Did the same damn thing. Disconnected battery and cleared codes. Ran great for a day, then all the same crap happened. Now whenever it acts up I cant even keep it running. I know its not any of the parts I already changed because the damn car will start up and run excellent over 50% of the time. My next try is for new connectors 2 for the relays for maf and 1 for the maf sensor itself. If that dont work I'm gonna buy a used ecm from hawks for $100. Does anyone have any input? This car is pissing me off.