Engine/Trans issues
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Engine/Trans issues
Hey guys! I'm new here and I have a lot of questions but I'll try to keep my posts short as possible. I just have bought a 1990 f150 xlt lariat with 302 5.0 engine. 33" tires. Not 100% sure what transmission is in it but it is an aod (no od button) It has PRNODD1. The pan has 14 bolts, and has RF E90P 7006AA. Door jam says trans type T? My biggest issue right now is that the truck seems to upshift way too soon. The guy that had it before me had the TV cable rigged with zip ties and a spring so I bought a new one but even though I followed instructions to adjust it its still not right. Shift points are 20 mph, 35, and 55 mph. Depending on how far pedal is pressed it can vary slightly. Also I have noticed it shift at 18 mph then again at about 25, 35. Once it hits 2nd and 3rd that's it. It bogs down unless I floor it then it kicks down and shifts back up and bogs again. It's way worse under light throttle on backroads. I'm having engine issues I'd like to talk about later too. Thanks for any help!
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The shift points sound correct for that trans, your problem is the 33" tires and the stock axle gear ratio which is likely way too tall for the way this truck is setup. What is the axle code on the drivers door pillar?
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I had the same truck you can see it there in my Avatar. When I first got it the truck could not maintain hwy speeds(60-70mph) on level ground into a headwind and that was with 31" tires. The immediate solution for you is to never use OD, just forget that it even exists and always select D when starting out.
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OK I'll try that for sure. Today it shifted at 18 mph then 23 needless to say it bogged down bad. My engine isn't running perfect either. At startup the idle goes up and down til warmed up and misses some too. My FPR vacuum hose smells of gas. Changed pcv valve, tps, air intake temp sensor and plugs. The terminals underneath my distributor cap are pitted a little so I plan on replacing that too. Also think I have an exhaust leak as 2 of my header bolts (1 on each side) are broke off in the engine. I appreciate your help! Oh and idk if the ecm has anything to do with transmission but I'm getting a code 15 (keep alive memory failure) checked 12v at pin 1 ground at 40 and 60 all good. Pins fitting into harness seem good. Also code 41 engine lean right side 02 sensor. The guy I bought it off of put header's and flowmasters on it so he cut the 02 sensors completely out.
Last edited by Ckn087; Nov 17, 2017 at 09:06 AM. Reason: Left something out
FTE Legend
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From: Ottawa, Ontario
That means the diaphram has ruptured, replace the FPR immediately.
That is no good, the O2 sensor(there is only 1) needs to be reinstalled in the passenger side header collector.
That is no good, the O2 sensor(there is only 1) needs to be reinstalled in the passenger side header collector.
Hotshot
Joined: May 2003
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From: south louisiana
And get that TV cable adjusted correctly, otherwise the transmission will be toast in short order. That's probably the problem with the erratic shifting, along with the too steep final drive ratio.
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Ok does that mean my fuel pressure is too low with the diaphragm being ruptured? Truck misses and idles up and down until warm. Kinda runs little roug too. And how do I go about putting an O2 sensor back in?
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What is the proper way to adjust that cable? Transmission is making weird sounds as I slow to a stop. I can actually hear the gears or something turning and occasionally a grinding sound. I do know that when I got it I had to force it out of 4H into 2H and the other day I tried pulling it back into 4H and it made a bad grinding sound. Would the stock gear setup and 33''s have anything to do with the weird shifting? Or the vehicle speed sensor?
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You can buy a header collector reducer with an O2 bung and install it
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A muffler shop should be able to help you with that, they can weld in a bung for the sensor in the header collector or in the head pipe near that.
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Have a look at this video. This gives you a good starting point, if you want a little firmer shift then carefully increase preload 1 notch at a time and test drive. If you do that several times and get to a point where the trans won't downshift properly when slowing down you have gone too far and need to back off a notch or two.
You may not have the t-case fully engaged or disgaged now. The shift linkage in these trucks are always seizing up, I strongly suggest you remove it from the truck, carefully dismantle and lube the pivot and reinstall. The shift linkage and lever are made from pot metal so you will break it if it gets really stuck and you force it. When operating correctly the t-case shifter should move through it's gates as easily as a manual transmission.
No.
No.
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Ok guys, I had a muffler shop weld a bung on and got my o2 sensor on and cleared my code 41. I also replaced the fpr. When I went to de-pressurize the fuel rail with the shrader valve, nothing came out at all. But now that the new one is on it idles lower than before. It was at 730 now 630 rpms and it runs a lot better than it was. It does idle wierd. It shoots up to 2k at startup then goes below 5k and tries to stall. Then it will go up and down until warmed up or until i give it gas as it tries to stall. Now, I'm getting a code 33 which my Haynes manual says is EGR valve not opening insufficient flow. I have actually watched my EGR valve open at 1/4 throttle or so. And I'm also getting code 73, 25, and 15. I have had 33, and 15 but never saw 25 or 73. I checked power to pin 1 and ground at 40 and 60. All checked out. Is my ecm bad? Is there a knock sensor on a 302 5.0? Thanks guys sorry for so many questions and I appreciate the help so far!
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From: south louisiana
There were knock sensors on some 5.0's but not all. Swapped the engine in a friends 92 E150, it had one. Only one I've run across though. have had several 90's E and F series with both 5.0 and 5.8, but that was the only one I've run across that had a knock sensor.
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Ok so if mine has one where would it be located? Drivers side intake? My engine just started making a knocking sound and it sounds like it's coming from underneath. It started after I put my first 16 oz of marvel misery oil. It's not pinging. Its more like a knock or pecking. My oil pressure gauge is either on the edge of the R in NORMAL or barely touching the N. Never stays in place. That's getting pretty low right?