Van wont rev past 2k

[mahleek87]

I got a new problem here and I made a YouTube video of what it's doing.


http://youtu.be/B3IrHWVjykw


I have been driving this van for the past weeks without any problem and I just stop driving it five days ago when I decided to take the battery out and put it in my other van because that one died and it was cold over here And van number 2 has heat.


I bought a new battery the other day installed it in number two and then took the battery out of that van and put it back in Vin number one and try to start it and this is what it does.

I don't see any check engine light but I will try to check for codes in about one hour and report back if there are any .


Off the top of my head I think it possibly could be a failing ignition coil this one has about 95,000 miles on it

[mahleek87]

Ok so I went back to the van after a couple of hours and started it up. It ran perfectly fine. I let it warm up and revved it and it seems the problem is gone.

Once I let it run for a while I revved it, it was completely fine. I even drove it and it was fine. It seems like the problem is intermittent or completely went away... The van looks like its back to normal. I guess it may have been a fluke for sitting for a week. It is old... Maybe the parts are worn out and will eventually need to be replaced, but seems like everything is back to normal


I did however see that when I first started it on a cold start, the check engine light came on for a second and the van shut off. Then I started it again and it was gone... SO I checked for codes and came up with 3 and 7

Igniter or TPS...

[timsrv]

Based on the video it appears to me to be a faulty ECU or perhaps a bad (shorted) TPS. If it does that again, unplug the TPS and see if the problem goes away. If it does, plug it back in to see if it returns. If you are able to duplicate/eliminate the problem by plugging/unplugging the TPS, then the problem is a shorted TPS.....specifically a short between the terminals "IDL" & "E1". If the problem is not effected by unplugging TPS, but remains, then it's most likely a failed ECU. There's also a very small chance there's a problem with the harness, so before condemning the ECU, I would pull the pins IDL & EI from it just to be sure.

The ECU is designed to shut off the fuel injectors @ 2200 RPM, then turn them back on @1800 RPM when TPS terminals IDL & E1 are shorted. This is called Fuel Cut RPM and is outlined in the FI section of the service manual (FI-74 of the 87 FSM). It's an emission thing that cuts off fuel flow while decelerating, but in your case, it appears to be turning off injectors while trying to accelerate (an obvious malfunction). Tim

PS: If your TPS has more than 100k miles on it, I would recommend replacing it (as they don't last much longer than that anyhow). If you replace the TPS & the problem returns, at least you can rule that out. Tim

[mahleek87]

Thanks for the reply Tim.

If it does turn out to be the ECU the good news is I have two spares (different) laying around somewhere. Hopefully one belongs to an 86.

I drove it a little and from my shop to my house 5 miles and it was good. I guess Im just going to have to wait until it acts up again. Hopefully it doesn't tomorrow because I have a wedding to do and planned on taking both of my vans down to do the job.