sully72

Hey, I'm new here, i have been reading your stuff for years but haven't ever joined but now im in need of some help and some of the advice on this bulletin is pretty good. Here is my dilemma... i put a 94 22re in my 85 with mostly no problems. Got it mostly all set up but the engine cuts out at 2k rpms and kind of bounces between 2k and about 1800 rpms. Any help would be wonderful as im in a time crunch to get back to school.
Thanks in advance
Jim

4Crawler

iTrader: (3)

Check the air flow meter and throttle position sensors for starters:
http://www.4crawler.com/4x4/CheapTricks/AFM/index.shtml
http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

sully72

ok, thank you very much. I was planning on adjusting the tps but didn't know that it could have that dramatic of an effect on the engine but I am still learning as I go. I will let you know how it goes... thanks for the help
Jim

sully72

OK went and checked the tps and afm today and no dice. Set the tps... no change... checked the afm and it was ok but i cut the top out and moved the lever back and fourth as it was continually revving up and cutting out and no changes except that when i moved it one way it would rev and cut out faster and the opposite way would take it longer to cycle. I played with the mixture a little and no changes. Pulled codes and got a knock sensor and tps but with the tps set i dont think it would be that or the knock sensor? Replaced knock sensor and no change. I'm at a loss here... I would be willing to bet that it is electrical but im not sure what it would be. Sorry for the long post. When i come down a hill and downshift and push the pedal it has the feeling like its out of gas. Revs fine right up to 2k and just stops, drops about 2k, and then goes back up to 2k all while i hold the pedal steady. What could cause this? Thanks in advance
Jim

4Crawler

iTrader: (3)

Try the fuel pump test jumper:
http://www.4crawler.com/4x4/CheapTri...shtml#FuelPump

sully72

Still the same... It says in that article the jumper will cause the fuel pump to be on any time the ignition is on... my truck already does that.I thought it was normal. Don't think it matters. thanks for sticking with me. what next

4Crawler

iTrader: (3)

Only time the fuel pump should normally run is either when the starter is cranking or whel the AFM flapper door is open (i.e. the engine is pulling in air). If you, for example, stall the engine, the fuel pump normally shuts off, even though the key/ignition is still on.

Might have a loose connection between the various sensors and the ECU. Might be worth checking for continuity in those circuits. I once had a loose AFM connector and the engine would cut out from time to time. Finally the ECU threw an AFM code and that led me to test those wires and I found (and fixed) the problem.

sully72

ok i will check but witch ones in particular do you think would cause this?
Jim

4Crawler

iTrader: (3)

Any that change resistance with the throttle position or engine speed for starters. And on the TPS, one test to try is disconnect it and see if the problem goes away or not. It will trip a check engine light, but should still run.

sully72

Ok I pulled the plug off the tps and fired it up just for kicks. Grabbed the throttle twisted it and it went up there in the rpms. interesting... so now it's fixed... sort of. I probably want the tps plugged in right? Does this mean that it's bad? I have another one around here but im not sure if its good. Actually i have a 94 one but i would have to splice the wires and would that even work? haha thanks for the help
Jim

4Crawler

iTrader: (3)

Probably means the TPS has a dropout in resistance on the VTA-E2 circuit.

sully72

Sorry to bomb you with q's but why do you think it didn't do this to my old engine only a week ago?

sully72

so i put the other tps on and it's the same deal... I wonder if i need to use the one that came with the engine? the 94. They did switch the throttle bodies. What do you think?
Jim

4Crawler

iTrader: (3)

You need a good TPS in any event, test the VTA-E2 resistance over the whole range of motion. Watch for a gradually increasing resistance as you open up up. You should see no sudden jumps or dips in resistance as you check it out. If it is OK at the TPS connector, you could repeat the test at the ECU connector (pinouts on the TPS page above). If that is all OK, you might have a case of a loose connection some place that is intermittent. At a certain engine RPM, it may vibrate just right to make the loose connection open up. Also, try resetting the ECU, pull power or EFI fuse for a few minutes.

sully72

After testing the wires to the tps (at the plug and from the ecu) it turned out that the wiring was fine, which was a relief because i was worried about rewiring it. I took the tps off to look at the inside and noticed something that i should have noticed a long time ago... The metal plate inside of the new throttle body is perpendicular to the old one! So i laughed at myself and out it all back together and it works fine... Just wanted to say thanks for the help and let you all know for future reference. Thanks again
Jim

coondogger

Had the same problem with a buddies EFI.......... There are two relays with the fuel pump. Run a wire straight from the fuel pump to the battery, and see if it will rev. past 2,000 rpm.

Jes85SR5

Im experiencing some what the same problem, did all of 4crawlers checks on tps, still throwing codes for tps and knock sensor. plate in throttle body? im unfamiliar, fill me in?